Convert.ToSingle 方法 (System) (2024)

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::String ^ value, IFormatProvider ^ provider);

public static float ToSingle (string value, IFormatProvider provider);

public static float ToSingle (string? value, IFormatProvider? provider);

static member ToSingle : string * IFormatProvider -> single

Public Shared Function ToSingle (value As String, provider As IFormatProvider) As Single

参数

返回

与 value 中数字等效的单精度浮点数，如果 value 为 null，则为 0（零）。

例外

示例

下面的示例在将数值字符串Single数组中的元素转换为值时，使用IFormatProvider表示 en-US 和 fr-FR 区域性的对象。

using System;using System.Globalization;public class Example{ public static void Main() { string[] values = { "123456789", "12345.6789", "12 345,6789", "123,456.789", "123 456,789", "123,456,789.0123", "123 456 789,0123", "1.235e12", "1.03221e-05", Double.MaxValue.ToString() }; CultureInfo[] cultures = { new CultureInfo("en-US"), new CultureInfo("fr-FR") }; foreach (CultureInfo culture in cultures) { Console.WriteLine("String -> Single Conversion Using the {0} Culture", culture.Name); foreach (string value in values) { Console.Write("{0,22} -> ", value); try { Console.WriteLine(Convert.ToSingle(value, culture)); } catch (FormatException) { Console.WriteLine("FormatException"); } catch (OverflowException) { Console.WriteLine("OverflowException"); } } Console.WriteLine(); } }}// The example displays the following output:// String -> Single Conversion Using the en-US Culture// 123456789 -> 1.234568E+08// 12345.6789 -> 12345.68// 12 345,6789 -> FormatException// 123,456.789 -> 123456.8// 123 456,789 -> FormatException// 123,456,789.0123 -> 1.234568E+08// 123 456 789,0123 -> FormatException// 1.235e12 -> 1.235E+12// 1.03221e-05 -> 1.03221E-05// 1.79769313486232E+308 -> Overflow//// String -> Single Conversion Using the fr-FR Culture// 123456789 -> 1.234568E+08// 12345.6789 -> FormatException// 12 345,6789 -> 12345.68// 123,456.789 -> FormatException// 123 456,789 -> 123456.8// 123,456,789.0123 -> FormatException// 123 456 789,0123 -> 1.234568E+08// 1.235e12 -> FormatException// 1.03221e-05 -> FormatException// 1.79769313486232E+308 -> FormatException

open Systemopen System.Globalizationlet values = [| "123456789"; "12345.6789"; "12 345,6789" "123,456.789"; "123 456,789"; "123,456,789.0123" "123 456 789,0123"; "1.235e12"; "1.03221e-05" string Double.MaxValue |]let cultures = [| CultureInfo "en-US"; CultureInfo "fr-FR" |]for culture in cultures do printfn $"String -> Single Conversion Using the {culture.Name} Culture" for value in values do printf $"{value,22} -> " try printfn $"{Convert.ToSingle(value, culture)}" with | :? FormatException -> printfn "FormatException" | :? OverflowException -> printfn "OverflowException" printfn ""// The example displays the following output:// String -> Single Conversion Using the en-US Culture// 123456789 -> 1.234568E+08// 12345.6789 -> 12345.68// 12 345,6789 -> FormatException// 123,456.789 -> 123456.8// 123 456,789 -> FormatException// 123,456,789.0123 -> 1.234568E+08// 123 456 789,0123 -> FormatException// 1.235e12 -> 1.235E+12// 1.03221e-05 -> 1.03221E-05// 1.79769313486232E+308 -> Overflow//// String -> Single Conversion Using the fr-FR Culture// 123456789 -> 1.234568E+08// 12345.6789 -> FormatException// 12 345,6789 -> 12345.68// 123,456.789 -> FormatException// 123 456,789 -> 123456.8// 123,456,789.0123 -> FormatException// 123 456 789,0123 -> 1.234568E+08// 1.235e12 -> FormatException// 1.03221e-05 -> FormatException// 1.79769313486232E+308 -> FormatException

Imports System.GlobalizationModule Example Public Sub Main() Dim values() As String = { "123456789", "12345.6789", "12 345,6789", _ "123,456.789", "123 456,789", "123,456,789.0123", _ "123 456 789,0123", "1.235e12", "1.03221e-05", _ Double.MaxValue.ToString() } Dim cultures() As CultureInfo = { New CultureInfo("en-US"), _ New CultureInfo("fr-FR") } For Each culture As CultureInfo In cultures Console.WriteLine("String -> Single Conversion Using the {0} Culture", _ culture.Name) For Each value As String In values Console.Write("{0,22} -> ", value) Try Console.WriteLine(Convert.ToSingle(value, culture)) Catch e As FormatException Console.WriteLine("FormatException") CAtch e As OverflowException Console.WriteLine("Overflow") End Try Next Console.WriteLine() Next End SubEnd Module' The example displays the following output:' String -> Single Conversion Using the en-US Culture' 123456789 -> 1.234568E+08' 12345.6789 -> 12345.68' 12 345,6789 -> FormatException' 123,456.789 -> 123456.8' 123 456,789 -> FormatException' 123,456,789.0123 -> 1.234568E+08' 123 456 789,0123 -> FormatException' 1.235e12 -> 1.235E+12' 1.03221e-05 -> 1.03221E-05' 1.79769313486232E+308 -> Overflow' ' String -> Single Conversion Using the fr-FR Culture' 123456789 -> 1.234568E+08' 12345.6789 -> FormatException' 12 345,6789 -> 12345.68' 123,456.789 -> FormatException' 123 456,789 -> 123456.8' 123,456,789.0123 -> FormatException' 123 456 789,0123 -> 1.234568E+08' 1.235e12 -> FormatException' 1.03221e-05 -> FormatException' 1.79769313486232E+308 -> FormatException

注解

返回值是在 上value调用 Single.Parse 方法的结果。

provider 是获取 IFormatProviderNumberFormatInfo 对象的实例。 对象 NumberFormatInfo 提供有关 格式的 value区域性特定信息。 如果 provider 为 null， NumberFormatInfo 则使用当前区域性的 。

如果希望在转换失败时不处理异常，可以改为调用 Single.TryParse 方法。 它返回一个 Boolean 值，该值指示转换是成功还是失败。

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::SByte value);

[System.CLSCompliant(false)]public static float ToSingle (sbyte value);

[<System.CLSCompliant(false)>]static member ToSingle : sbyte -> single

Public Shared Function ToSingle (value As SByte) As Single

参数

返回

一个与 value 等效的 8 位带符号整数。

属性

CLSCompliantAttribute

示例

以下示例将有符号字节数组中的每个元素转换为 Single 值。

sbyte[] numbers = { SByte.MinValue, -23, 0, 17, SByte.MaxValue };float result;foreach (sbyte number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the SByte value '-128' to the Single value -128.// Converted the SByte value '-23' to the Single value -23.// Converted the SByte value '0' to the Single value 0.// Converted the SByte value '17' to the Single value 17.// Converted the SByte value '127' to the Single value 127.

let numbers = [| SByte.MinValue; -23y; 0y; 17y; SByte.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the SByte value '-128' to the Single value -128.// Converted the SByte value '-23' to the Single value -23.// Converted the SByte value '0' to the Single value 0.// Converted the SByte value '17' to the Single value 17.// Converted the SByte value '127' to the Single value 127.

Dim numbers() As SByte = { SByte.MinValue, -23, 0, 17, SByte.MaxValue }Dim result As SingleFor Each number As SByte In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the SByte value '-128' to the Single value -128.' Converted the SByte value '-23' to the Single value -23.' Converted the SByte value '0' to the Single value 0.' Converted the SByte value '17' to the Single value 17.' Converted the SByte value '127' to the Single value 127.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::Object ^ value, IFormatProvider ^ provider);

public static float ToSingle (object value, IFormatProvider provider);

public static float ToSingle (object? value, IFormatProvider? provider);

static member ToSingle : obj * IFormatProvider -> single

Public Shared Function ToSingle (value As Object, provider As IFormatProvider) As Single

参数

返回

与 value 等效的单精度浮点数，如果 value 为 null，则为零。

例外

示例

下面的示例定义一个实现 Temperature 接口的 IConvertible 类。 该方法的 IConvertible.ToSingle 实现返回表示温度的私有 Single 变量的内部值。

using System;using System.Globalization;public class Temperature : IConvertible{ private float m_Temp; public Temperature(float temperature) { this.m_Temp = temperature; } public float Celsius { get { return this.m_Temp; } } public float Kelvin { get { return this.m_Temp + 273.15f; } } public float Fahrenheit { get { return (float) Math.Round(this.m_Temp * 9 / 5 + 32, 2); } } public override string ToString() { return m_Temp.ToString("N2") + " °C"; } // IConvertible implementations. public TypeCode GetTypeCode() { return TypeCode.Object; } public bool ToBoolean(IFormatProvider provider) { if (m_Temp == 0) return false; else return true; } public byte ToByte(IFormatProvider provider) { if (m_Temp < Byte.MinValue || m_Temp > Byte.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the Byte type.", this.m_Temp)); else return Convert.ToByte(this.m_Temp); } public char ToChar(IFormatProvider provider) { throw new InvalidCastException("Temperature to Char conversion is not supported."); } public DateTime ToDateTime(IFormatProvider provider) { throw new InvalidCastException("Temperature to DateTime conversion is not supported."); } public decimal ToDecimal(IFormatProvider provider) { return Convert.ToDecimal(this.m_Temp); } public double ToDouble(IFormatProvider provider) { return Convert.ToDouble(this.m_Temp); } public short ToInt16(IFormatProvider provider) { if (this.m_Temp < Int16.MinValue || this.m_Temp > Int16.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the Int16 type.", this.m_Temp)); else return Convert.ToInt16(this.m_Temp); } public int ToInt32(IFormatProvider provider) { if (this.m_Temp < Int32.MinValue || this.m_Temp > Int32.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the Int32 type.", this.m_Temp)); else return Convert.ToInt32(this.m_Temp); } public long ToInt64(IFormatProvider provider) { if (this.m_Temp < Int64.MinValue || this.m_Temp > Int64.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the Int64 type.", this.m_Temp)); else return Convert.ToInt64(this.m_Temp); } public sbyte ToSByte(IFormatProvider provider) { if (this.m_Temp < SByte.MinValue || this.m_Temp > SByte.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the SByte type.", this.m_Temp)); else return Convert.ToSByte(this.m_Temp); } public float ToSingle(IFormatProvider provider) { return this.m_Temp; } public string ToString(IFormatProvider provider) { return m_Temp.ToString("N2", provider) + " °C"; } public object ToType(Type conversionType, IFormatProvider provider) { switch (Type.GetTypeCode(conversionType)) { case TypeCode.Boolean: return this.ToBoolean(null); case TypeCode.Byte: return this.ToByte(null); case TypeCode.Char: return this.ToChar(null); case TypeCode.DateTime: return this.ToDateTime(null); case TypeCode.Decimal: return this.ToDecimal(null); case TypeCode.Double: return this.ToDouble(null); case TypeCode.Int16: return this.ToInt16(null); case TypeCode.Int32: return this.ToInt32(null); case TypeCode.Int64: return this.ToInt64(null); case TypeCode.Object: if (typeof(Temperature).Equals(conversionType)) return this; else throw new InvalidCastException(String.Format("Conversion to a {0} is not supported.", conversionType.Name)); case TypeCode.SByte: return this.ToSByte(null); case TypeCode.Single: return this.ToSingle(null); case TypeCode.String: return this.ToString(provider); case TypeCode.UInt16: return this.ToUInt16(null); case TypeCode.UInt32: return this.ToUInt32(null); case TypeCode.UInt64: return this.ToUInt64(null); default: throw new InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name)); } } public ushort ToUInt16(IFormatProvider provider) { if (this.m_Temp < UInt16.MinValue || this.m_Temp > UInt16.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the UInt16 type.", this.m_Temp)); else return Convert.ToUInt16(this.m_Temp); } public uint ToUInt32(IFormatProvider provider) { if (this.m_Temp < UInt32.MinValue || this.m_Temp > UInt32.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the UInt32 type.", this.m_Temp)); else return Convert.ToUInt32(this.m_Temp); } public ulong ToUInt64(IFormatProvider provider) { if (this.m_Temp < UInt64.MinValue || this.m_Temp > UInt64.MaxValue) throw new OverflowException(String.Format("{0} is out of range of the UInt64 type.", this.m_Temp)); else return Convert.ToUInt64(this.m_Temp); }}

open Systemtype Temperature(temperature: float32) = member _.Celsius = temperature member _.Kelvin = temperature + 273.15f member _.Fahrenheit = MathF.Round(temperature * 9f / 5f + 32f, 2) override _.ToString() = $"{temperature:N2} °C" // IConvertible implementations. interface IConvertible with member _.GetTypeCode() = TypeCode.Object member _.ToBoolean(provider: IFormatProvider) = temperature <> 0f member _.ToByte(provider: IFormatProvider) = if temperature < float32 Byte.MinValue || temperature > float32 Byte.MaxValue then raise (OverflowException $"{temperature} is out of range of the Byte type.") else Convert.ToByte temperature member _.ToChar(provider: IFormatProvider) = raise (InvalidCastException "Temperature to Char conversion is not supported.") member _.ToDateTime(provider: IFormatProvider) = raise (InvalidCastException "Temperature to DateTime conversion is not supported.") member _.ToDecimal(provider: IFormatProvider) = Convert.ToDecimal temperature member _.ToDouble(provider: IFormatProvider) = Convert.ToDouble temperature member _.ToInt16(provider: IFormatProvider) = if temperature < float32 Int16.MinValue || temperature > float32 Int16.MaxValue then raise (OverflowException $"{temperature} is out of range of the Int16 type.") else Convert.ToInt16 temperature member _.ToInt32(provider: IFormatProvider) = if temperature < float32 Int32.MinValue || temperature > float32 Int32.MaxValue then raise (OverflowException $"{temperature} is out of range of the Int32 type.") else Convert.ToInt32 temperature member _.ToInt64(provider: IFormatProvider) = if float32 temperature < float32 Int64.MinValue || temperature > float32 Int64.MaxValue then raise (OverflowException $"{temperature} is out of range of the Int64 type.") else Convert.ToInt64 temperature member _.ToSByte(provider: IFormatProvider) = if temperature < float32 SByte.MinValue || temperature > float32 SByte.MaxValue then raise (OverflowException $"{temperature} is out of range of the SByte type.") else Convert.ToSByte temperature member _.ToSingle(provider: IFormatProvider) = temperature override _.ToString(provider: IFormatProvider) = temperature.ToString("N2", provider) + " °C" member this.ToType(conversionType: Type, provider: IFormatProvider) = let this = this :> IConvertible match Type.GetTypeCode conversionType with | TypeCode.Boolean -> this.ToBoolean null | TypeCode.Byte -> this.ToByte null | TypeCode.Char -> this.ToChar null | TypeCode.DateTime -> this.ToDateTime null | TypeCode.Decimal -> this.ToDecimal null | TypeCode.Double -> this.ToDouble null | TypeCode.Int16 -> this.ToInt16 null | TypeCode.Int32 -> this.ToInt32 null | TypeCode.Int64 -> this.ToInt64 null | TypeCode.Object -> if typeof<Temperature>.Equals conversionType then this else raise (InvalidCastException $"Conversion to a {conversionType.Name} is not supported.") | TypeCode.SByte -> this.ToSByte null | TypeCode.Single -> this.ToSingle null | TypeCode.String -> this.ToString provider | TypeCode.UInt16 -> this.ToUInt16 null | TypeCode.UInt32 -> this.ToUInt32 null | TypeCode.UInt64 -> this.ToUInt64 null | _ -> raise (InvalidCastException $"Conversion to {conversionType.Name} is not supported.") member _.ToUInt16(provider: IFormatProvider) = if temperature < float32 UInt16.MinValue || temperature > float32 UInt16.MaxValue then raise (OverflowException $"{temperature} is out of range of the UInt16 type.") else Convert.ToUInt16 temperature member _.ToUInt32(provider: IFormatProvider) = if temperature < float32 UInt32.MinValue || temperature > float32 UInt32.MaxValue then raise (OverflowException $"{temperature} is out of range of the UInt32 type.") else Convert.ToUInt32 temperature member _.ToUInt64(provider: IFormatProvider) = if temperature < float32 UInt64.MinValue || temperature > float32 UInt64.MaxValue then raise (OverflowException $"{temperature} is out of range of the UInt64 type.") else Convert.ToUInt64 temperature

Imports System.GlobalizationPublic Class Temperature : Implements IConvertible Private m_Temp As Single Public Sub New(temperature As Single) Me.m_Temp = temperature End Sub Public ReadOnly Property Celsius() As Single Get Return Me.m_Temp End Get End Property Public ReadOnly Property Kelvin() As Single Get Return Me.m_Temp + 273.15F End Get End Property Public ReadOnly Property Fahrenheit() As Single Get Return CSng(Math.Round(Me.m_Temp * 9 / 5 + 32, 2)) End Get End Property Public Overrides Function ToString() As String Return m_Temp.ToString("N2") & " °C" End Function ' IConvertible implementations. Public Function GetTypeCode() As TypeCode _ Implements IConvertible.GetTypeCode Return TypeCode.Object End Function Public Function ToBoolean(provider As IFormatProvider) As Boolean _ Implements IConvertible.ToBoolean If m_Temp = 0 Then Return False Else Return True End If End Function Public Function ToByte(provider As IFormatProvider) As Byte _ Implements IConvertible.ToByte If m_Temp < Byte.MinValue Or m_Temp > Byte.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the Byte type.", _ Me.m_Temp)) Else Return Convert.ToByte(Me.m_Temp) End If End Function Public Function ToChar(provider As IFormatProvider) As Char _ Implements IConvertible.ToChar Throw New InvalidCastException("Temperature to Char conversion is not supported.") End Function Public Function ToDateTime(provider As IFormatProvider) As Date _ Implements IConvertible.ToDateTime Throw New InvalidCastException("Temperature to DateTime conversion is not supported.") End Function Public Function ToDecimal(provider As IFormatProvider) As Decimal _ Implements IConvertible.ToDecimal Return Convert.ToDecimal(Me.m_Temp) End Function Public Function ToDouble(provider As IFormatProvider) As Double _ Implements IConvertible.ToDouble Return Convert.ToDouble(Me.m_Temp) End Function Public Function ToInt16(provider As IFormatProvider) As Int16 _ Implements IConvertible.ToInt16 If Me.m_Temp < Int16.MinValue Or Me.m_Temp > Int16.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the Int16 type.", _ Me.m_Temp)) Else Return Convert.ToInt16(Me.m_Temp) End If End Function Public Function ToInt32(provider As IFormatProvider) As Int32 _ Implements IConvertible.ToInt32 If Me.m_Temp < Int32.MinValue Or Me.m_Temp > Int32.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the Int32 type.", _ Me.m_Temp)) Else Return Convert.ToInt32(Me.m_Temp) End If End Function Public Function ToInt64(provider As IFormatProvider) As Int64 _ Implements IConvertible.ToInt64 If Me.m_Temp < Int64.MinValue Or Me.m_Temp > Int64.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the Int64 type.", _ Me.m_Temp)) Else Return Convert.ToInt64(Me.m_Temp) End If End Function Public Function ToSByte(provider As IFormatProvider) As SByte _ Implements IConvertible.ToSByte If Me.m_Temp < SByte.MinValue Or Me.m_Temp > SByte.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the SByte type.", _ Me.m_Temp)) Else Return Convert.ToSByte(Me.m_Temp) End If End Function Public Function ToSingle(provider As IFormatProvider) As Single _ Implements IConvertible.ToSingle Return Me.m_Temp End Function Public Overloads Function ToString(provider As IFormatProvider) As String _ Implements IConvertible.ToString Return m_Temp.ToString("N2", provider) & " °C" End Function Public Function ToType(conversionType As Type, provider As IFormatProvider) As Object _ Implements IConvertible.ToType Select Case Type.GetTypeCode(conversionType) Case TypeCode.Boolean Return Me.ToBoolean(Nothing) Case TypeCode.Byte Return Me.ToByte(Nothing) Case TypeCode.Char Return Me.ToChar(Nothing) Case TypeCode.DateTime Return Me.ToDateTime(Nothing) Case TypeCode.Decimal Return Me.ToDecimal(Nothing) Case TypeCode.Double Return Me.ToDouble(Nothing) Case TypeCode.Int16 Return Me.ToInt16(Nothing) Case TypeCode.Int32 Return Me.ToInt32(Nothing) Case TypeCode.Int64 Return Me.ToInt64(Nothing) Case TypeCode.Object If GetType(Temperature).Equals(conversionType) Then Return Me Else Throw New InvalidCastException(String.Format("Conversion to a {0} is not supported.", _ conversionType.Name)) End If Case TypeCode.SByte Return Me.ToSByte(Nothing) Case TypeCode.Single Return Me.ToSingle(Nothing) Case TypeCode.String Return Me.ToString(provider) Case TypeCode.UInt16 Return Me.ToUInt16(Nothing) Case TypeCode.UInt32 Return Me.ToUInt32(Nothing) Case TypeCode.UInt64 Return Me.ToUInt64(Nothing) Case Else Throw New InvalidCastException(String.Format("Conversion to {0} is not supported.", conversionType.Name)) End Select End Function Public Function ToUInt16(provider As IFormatProvider) As UInt16 _ Implements IConvertible.ToUInt16 If Me.m_Temp < UInt16.MinValue Or Me.m_Temp > UInt16.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the UInt16 type.", _ Me.m_Temp)) Else Return Convert.ToUInt16(Me.m_Temp) End If End Function Public Function ToUInt32(provider As IFormatProvider) As UInt32 _ Implements IConvertible.ToUInt32 If Me.m_Temp < UInt32.MinValue Or Me.m_Temp > UInt32.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the UInt32 type.", _ Me.m_Temp)) Else Return Convert.ToUInt32(Me.m_Temp) End If End Function Public Function ToUInt64(provider As IFormatProvider) As UInt64 _ Implements IConvertible.ToUInt64 If Me.m_Temp < UInt64.MinValue Or Me.m_Temp > UInt64.MaxValue Then Throw New OverflowException(String.Format("{0} is out of range of the UInt64 type.", _ Me.m_Temp)) Else Return Convert.ToUInt64(Me.m_temp) End If End FunctionEnd Class

下面的示例说明了对 方法的 Convert.ToSingle(Object, IFormatProvider) 调用如何反过来调用 IConvertible.ToSingle 类的 Temperature 实现。

public class Example{ public static void Main() { Temperature cold = new Temperature(-40); Temperature freezing = new Temperature(0); Temperature boiling = new Temperature(100); Console.WriteLine(Convert.ToInt32(cold, null)); Console.WriteLine(Convert.ToInt32(freezing, null)); Console.WriteLine(Convert.ToDouble(boiling, null)); }}// The example dosplays the following output:// -40// 0// 100

let cold = Temperature -40flet freezing = Temperature 0flet boiling = Temperature 100fprintfn $"{Convert.ToInt32(cold, null)}"printfn $"{Convert.ToInt32(freezing, null)}"printfn $"{Convert.ToDouble(boiling, null)}"// The example dosplays the following output:// -40// 0// 100

Module Example Public Sub Main() Dim cold As New Temperature(-40) Dim freezing As New Temperature(0) Dim boiling As New Temperature(100) Console.WriteLine(Convert.ToInt32(cold, Nothing)) Console.WriteLine(Convert.ToInt32(freezing, Nothing)) Console.WriteLine(Convert.ToDouble(boiling, Nothing)) End SubEnd Module' The example displays the following output:' -40' 0' 100

注解

返回值是调用 IConvertible.ToSingle 的基础类型的 value方法的结果。

provider 使用户能够指定有关 的内容 value的区域性特定转换信息。 例如，如果 value 是 String 表示数字的 ， provider 则可提供有关用于表示该数字的表示法的区域性特定信息。

基类型忽略 provider;但是，如果 value 是实现 IConvertible 接口的用户定义类型，则可以使用 参数。

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::UInt64 value);

[System.CLSCompliant(false)]public static float ToSingle (ulong value);

[<System.CLSCompliant(false)>]static member ToSingle : uint64 -> single

Public Shared Function ToSingle (value As ULong) As Single

参数

返回

一个等于 value 的单精度浮点数。

属性

CLSCompliantAttribute

示例

以下示例将无符号长整数数组中的每个元素转换为 Single 值。

ulong[] numbers = { UInt64.MinValue, 121, 12345, UInt64.MaxValue };float result;foreach (ulong number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the UInt64 value '0' to the Single value 0.// Converted the UInt64 value '121' to the Single value 121.// Converted the UInt64 value '12345' to the Single value 12345.// Converted the UInt64 value '18446744073709551615' to the Single value 1.844674E+19.

let numbers = [| UInt64.MinValue; 121uL; 12345uL; UInt64.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the UInt64 value '0' to the Single value 0.// Converted the UInt64 value '121' to the Single value 121.// Converted the UInt64 value '12345' to the Single value 12345.// Converted the UInt64 value '18446744073709551615' to the Single value 1.844674E+19.

Dim numbers() As ULong = { UInt64.MinValue, 121, 12345, UInt64.MaxValue }Dim result As SingleFor Each number As ULong In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the UInt64 value '0' to the Single value 0.' Converted the UInt64 value '121' to the Single value 121.' Converted the UInt64 value '12345' to the Single value 12345.' Converted the UInt64 value '18446744073709551615' to the Single value 1.844674E+19.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::UInt32 value);

[System.CLSCompliant(false)]public static float ToSingle (uint value);

[<System.CLSCompliant(false)>]static member ToSingle : uint32 -> single

Public Shared Function ToSingle (value As UInteger) As Single

参数

返回

一个等于 value 的单精度浮点数。

属性

CLSCompliantAttribute

示例

以下示例将无符号整数数组中的每个元素转换为 Single 值。

uint[] numbers = { UInt32.MinValue, 121, 12345, UInt32.MaxValue };float result;foreach (uint number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the UInt32 value '0' to the Single value 0.// Converted the UInt32 value '121' to the Single value 121.// Converted the UInt32 value '12345' to the Single value 12345.// Converted the UInt32 value '4294967295' to the Single value 4.294967E+09.

let numbers = [| UInt32.MinValue; 121u; 12345u; UInt32.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the UInt32 value '0' to the Single value 0.// Converted the UInt32 value '121' to the Single value 121.// Converted the UInt32 value '12345' to the Single value 12345.// Converted the UInt32 value '4294967295' to the Single value 4.294967E+09.

 Dim numbers() As UInteger = { UInt32.MinValue, 121, 12345, UInt32.MaxValue } Dim result As Single For Each number As UInteger In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result) Next ' The example displays the following output:' Converted the UInt32 value '0' to the Single value 0.' Converted the UInt32 value '121' to the Single value 121.' Converted the UInt32 value '12345' to the Single value 12345.' Converted the UInt32 value '4294967295' to the Single value 4.294967E+09.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::String ^ value);

public static float ToSingle (string value);

public static float ToSingle (string? value);

static member ToSingle : string -> single

Public Shared Function ToSingle (value As String) As Single

参数

返回

与 value 中数字等效的单精度浮点数，如果 value 为 null，则为 0（零）。

例外

示例

以下示例尝试将数值字符串数组中的每个元素转换为 Single 值。

string[] values= { "-1,035.77219", "1AFF", "1e-35", "1.63f", "1,635,592,999,999,999,999,999,999", "-17.455", "190.34001", "1.29e325"};float result;foreach (string value in values){ try { result = Convert.ToSingle(value); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", value.GetType().Name, value, result.GetType().Name, result); } catch (FormatException) { Console.WriteLine("Unable to convert '{0}' to a Single.", value); } catch (OverflowException) { Console.WriteLine("'{0}' is outside the range of a Single.", value); }}// The example displays the following output:// Converted the String value '-1,035.77219' to the Single value -1035.772.// Unable to convert '1AFF' to a Single.// Converted the String value '1e-35' to the Single value 1E-35.// Unable to convert '1.63f' to a Single.// Converted the String value '1,635,592,999,999,999,999,999,999' to the Single value 1.635593E+24.// Converted the String value '-17.455' to the Single value -17.455.// Converted the String value '190.34001' to the Single value 190.34.// 1.29e325' is outside the range of a Single.

let values = [| "-1,035.77219"; "1AFF"; "1e-35"; "1.63f"; "1,635,592,999,999,999,999,999,999" "-17.455"; "190.34001"; "1.29e325" |]for value in values do try let result = Convert.ToSingle value printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}." with | :? FormatException -> printfn $"Unable to convert '{value}' to a Single." | :? OverflowException -> printfn $"'{value}' is outside the range of a Single."// The example displays the following output:// Converted the String value '-1,035.77219' to the Single value -1035.772.// Unable to convert '1AFF' to a Single.// Converted the String value '1e-35' to the Single value 1E-35.// Unable to convert '1.63f' to a Single.// Converted the String value '1,635,592,999,999,999,999,999,999' to the Single value 1.635593E+24.// Converted the String value '-17.455' to the Single value -17.455.// Converted the String value '190.34001' to the Single value 190.34.// 1.29e325' is outside the range of a Single.

Dim values() As String = { "-1,035.77219", "1AFF", "1e-35", "1.63f", "1,635,592,999,999,999,999,999,999", "-17.455", "190.34001", "1.29e325"}Dim result As SingleFor Each value As String In values Try result = Convert.ToSingle(value) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", value.GetType().Name, value, _ result.GetType().Name, result) Catch e As FormatException Console.WriteLine("Unable to convert '{0}' to a Single.", value) Catch e As OverflowException Console.WriteLine("'{0}' is outside the range of a Single.", value) End TryNext' The example displays the following output:' Converted the String value '-1,035.77219' to the Single value -1035.772.' Unable to convert '1AFF' to a Single.' Converted the String value '1e-35' to the Single value 1E-35.' Unable to convert '1.63f' to a Single.' Converted the String value '1,635,592,999,999,999,999,999,999' to the Single value 1.635593E+24.' Converted the String value '-17.455' to the Single value -17.455.' Converted the String value '190.34001' to the Single value 190.34.' '1.29e325' is outside the range of a Single.

注解

ToSingle(String)使用 方法等效于将 传递给 valueSingle.Parse(String) 方法。 value 通过使用当前区域性的格式设置约定进行解释。

如果希望在转换失败时不处理异常，可以改为调用 Single.TryParse 方法。 它返回一个 Boolean 值，该值指示转换是成功还是失败。

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(float value);

public static float ToSingle (float value);

static member ToSingle : single -> single

Public Shared Function ToSingle (value As Single) As Single

参数

返回

不经更改即返回 value。

另请参阅

• Single

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::Object ^ value);

public static float ToSingle (object value);

public static float ToSingle (object? value);

static member ToSingle : obj -> single

Public Shared Function ToSingle (value As Object) As Single

参数

返回

与 value 等效的单精度浮点数，如果 value 为 null，则为零。

例外

示例

以下示例尝试将对象数组中的每个元素转换为 Single 值。

object[] values = { true, 'a', 123, 1.764e32, "9.78", "1e-02", 1.67e03, "A100", "1,033.67", DateTime.Now, Decimal.MaxValue };float result;foreach (object value in values){ try { result = Convert.ToSingle(value); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", value.GetType().Name, value, result.GetType().Name, result); } catch (FormatException) { Console.WriteLine("The {0} value {1} is not recognized as a valid Single value.", value.GetType().Name, value); } catch (OverflowException) { Console.WriteLine("The {0} value {1} is outside the range of the Single type.", value.GetType().Name, value); } catch (InvalidCastException) { Console.WriteLine("Conversion of the {0} value {1} to a Single is not supported.", value.GetType().Name, value); }}// The example displays the following output:// Converted the Boolean value 'True' to the Single value 1.// Conversion of the Char value a to a Single is not supported.// Converted the Int32 value '123' to the Single value 123.// Converted the Double value '1.764E+32' to the Single value 1.764E+32.// Converted the String value '9.78' to the Single value 9.78.// Converted the String value '1e-02' to the Single value 0.01.// Converted the Double value '1670' to the Single value 1670.// The String value A100 is not recognized as a valid Single value.// Converted the String value '1,033.67' to the Single value 1033.67.// Conversion of the DateTime value 11/7/2008 08:02:35 AM to a Single is not supported.// Converted the Decimal value '79228162514264337593543950335' to the Single value 7.922816E+28.

let values: obj[] = [| true; 'a'; 123; 1.764e32; "9.78"; "1e-02"; 1.67e03; "A100"; "1,033.67"; DateTime.Now; Decimal.MaxValue |]for value in values do try let result = Convert.ToSingle value printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}." with | :? FormatException -> printfn $"The {value.GetType().Name} value {value} is not recognized as a valid Single value." | :? OverflowException -> printfn $"The {value.GetType().Name} value {value} is outside the range of the Single type." | :? InvalidCastException -> printfn $"Conversion of the {value.GetType().Name} value {value} to a Single is not supported."// The example displays the following output:// Converted the Boolean value 'True' to the Single value 1.// Conversion of the Char value a to a Single is not supported.// Converted the Int32 value '123' to the Single value 123.// Converted the Double value '1.764E+32' to the Single value 1.764E+32.// Converted the String value '9.78' to the Single value 9.78.// Converted the String value '1e-02' to the Single value 0.01.// Converted the Double value '1670' to the Single value 1670.// The String value A100 is not recognized as a valid Single value.// Converted the String value '1,033.67' to the Single value 1033.67.// Conversion of the DateTime value 11/7/2008 08:02:35 AM to a Single is not supported.// Converted the Decimal value '79228162514264337593543950335' to the Single value 7.922816E+28.

Dim values() As Object = { True, "a"c, 123, 1.764e32, "9.78", "1e-02", _ 1.67e03, "A100", "1,033.67", Date.Now, _ Decimal.MaxValue }Dim result As SingleFor Each value As Object In values Try result = Convert.ToSingle(value) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ value.GetType().Name, value, _ result.GetType().Name, result) Catch e As FormatException Console.WriteLine("The {0} value {1} is not recognized as a valid Single value.", _ value.GetType().Name, value) Catch e As OverflowException Console.WriteLine("The {0} value {1} is outside the range of the Single type.", _ value.GetType().Name, value) Catch e As InvalidCastException Console.WriteLine("Conversion of the {0} value {1} to a Single is not supported.", _ value.GetType().Name, value) End TryNext' The example displays the following output:' Converted the Boolean value 'True' to the Single value 1.' Conversion of the Char value a to a Single is not supported.' Converted the Int32 value '123' to the Single value 123.' Converted the Double value '1.764E+32' to the Single value 1.764E+32.' Converted the String value '9.78' to the Single value 9.78.' Converted the String value '1e-02' to the Single value 0.01.' Converted the Double value '1670' to the Single value 1670.' The String value A100 is not recognized as a valid Single value.' Converted the String value '1,033.67' to the Single value 1033.67.' Conversion of the DateTime value 11/7/2008 07:56:24 AM to a Single is not supported.' Converted the Decimal value '79228162514264337593543950335' to the Single value 7.922816E+28.

注解

返回值是调用 IConvertible.ToSingle 基础类型的 value方法的结果。

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::UInt16 value);

[System.CLSCompliant(false)]public static float ToSingle (ushort value);

[<System.CLSCompliant(false)>]static member ToSingle : uint16 -> single

Public Shared Function ToSingle (value As UShort) As Single

参数

返回

一个等于 value 的单精度浮点数。

属性

CLSCompliantAttribute

示例

以下示例将无符号 16 位整数数组中的每个元素转换为 Single 值。

ushort[] numbers = { UInt16.MinValue, 121, 12345, UInt16.MaxValue };float result;foreach (ushort number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the UInt16 value '0' to the Single value 0.// Converted the UInt16 value '121' to the Single value 121.// Converted the UInt16 value '12345' to the Single value 12345.// Converted the UInt16 value '65535' to the Single value 65535.

let numbers = [| UInt16.MinValue; 121us; 12345us; UInt16.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the UInt16 value '0' to the Single value 0.// Converted the UInt16 value '121' to the Single value 121.// Converted the UInt16 value '12345' to the Single value 12345.// Converted the UInt16 value '65535' to the Single value 65535.

Dim numbers() As UShort = { UInt16.MinValue, 121, 12345, UInt16.MaxValue }Dim result As SingleFor Each number As UShort In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the UInt16 value '0' to the Single value 0.' Converted the UInt16 value '121' to the Single value 121.' Converted the UInt16 value '12345' to the Single value 12345.' Converted the UInt16 value '65535' to the Single value 65535.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(int value);

public static float ToSingle (int value);

static member ToSingle : int -> single

Public Shared Function ToSingle (value As Integer) As Single

参数

返回

一个等于 value 的单精度浮点数。

示例

以下示例将整数数组中的每个元素转换为 Single 值。

int[] numbers = { Int32.MinValue, -1000, 0, 1000, Int32.MaxValue };float result;foreach (int number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the Int32 value '-2147483648' to the Single value -2.147484E+09.// Converted the Int32 value '-1000' to the Single value -1000.// Converted the Int32 value '0' to the Single value 0.// Converted the Int32 value '1000' to the Single value 1000.// Converted the Int32 value '2147483647' to the Single value 2.147484E+09.

let numbers = [| Int32.MinValue; -1000; 0; 1000; Int32.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the Int32 value '-2147483648' to the Single value -2.147484E+09.// Converted the Int32 value '-1000' to the Single value -1000.// Converted the Int32 value '0' to the Single value 0.// Converted the Int32 value '1000' to the Single value 1000.// Converted the Int32 value '2147483647' to the Single value 2.147484E+09.

Dim numbers() As Integer = { Int32.MinValue, -1000, 0, 1000, Int32.MaxValue }Dim result As SingleFor Each number As Integer In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the Int32 value '-2147483648' to the Single value -2.147484E+09.' Converted the Int32 value '-1000' to the Single value -1000.' Converted the Int32 value '0' to the Single value 0.' Converted the Int32 value '1000' to the Single value 1000.' Converted the Int32 value '2147483647' to the Single value 2.147484E+09.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(short value);

public static float ToSingle (short value);

static member ToSingle : int16 -> single

Public Shared Function ToSingle (value As Short) As Single

参数

返回

一个等于 value 的单精度浮点数。

示例

以下示例将 16 位整数数组中的每个元素转换为 Single 值。

short[] numbers = { Int16.MinValue, -1032, 0, 192, Int16.MaxValue };float result;foreach (short number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the Int16 value '-32768' to the Single value -32768.// Converted the Int16 value '-1032' to the Single value -1032.// Converted the Int16 value '0' to the Single value 0.// Converted the Int16 value '192' to the Single value 192.// Converted the Int16 value '32767' to the Single value 32767.

let numbers = [| Int16.MinValue; -1032s; 0s; 192s; Int16.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the Int16 value '-32768' to the Single value -32768.// Converted the Int16 value '-1032' to the Single value -1032.// Converted the Int16 value '0' to the Single value 0.// Converted the Int16 value '192' to the Single value 192.// Converted the Int16 value '32767' to the Single value 32767.

Dim numbers() As Short = { Int16.MinValue, -1032, 0, 192, Int16.MaxValue }Dim result As SingleFor Each number As Short In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the Int16 value '-32768' to the Single value -32768.' Converted the Int16 value '-1032' to the Single value -1032.' Converted the Int16 value '0' to the Single value 0.' Converted the Int16 value '192' to the Single value 192.' Converted the Int16 value '32767' to the Single value 32767.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(double value);

public static float ToSingle (double value);

static member ToSingle : double -> single

Public Shared Function ToSingle (value As Double) As Single

参数

返回

一个等于 value 的单精度浮点数。

使用“舍入为最接近的数字”规则对 value 进行舍入。 例如，当舍入为两位小数时，值 2.345 变成 2.34，而值 2.355 变成 2.36。

示例

以下示例将值数组 Double 中的每个元素转换为 Single 值。

double[] values = { Double.MinValue, -1.38e10, -1023.299, -12.98, 0, 9.113e-16, 103.919, 17834.191, Double.MaxValue };float result;foreach (double value in values){ result = Convert.ToSingle(value); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", value.GetType().Name, value, result.GetType().Name, result);}// The example displays the following output:// Converted the Double value '-1.79769313486232E+308' to the Single value -Infinity.// Converted the Double value '-13800000000' to the Single value -1.38E+10.// Converted the Double value '-1023.299' to the Single value -1023.299.// Converted the Double value '-12.98' to the Single value -12.98.// Converted the Double value '0' to the Single value 0.// Converted the Double value '9.113E-16' to the Single value 9.113E-16.// Converted the Double value '103.919' to the Single value 103.919.// Converted the Double value '17834.191' to the Single value 17834.19.// Converted the Double value '1.79769313486232E+308' to the Single value Infinity.

let values = [| Double.MinValue; -1.38e10; -1023.299; -12.98; 0; 9.113e-16; 103.919; 17834.191; Double.MaxValue |]for value in values do let result = Convert.ToSingle value printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the Double value '-1.79769313486232E+308' to the Single value -Infinity.// Converted the Double value '-13800000000' to the Single value -1.38E+10.// Converted the Double value '-1023.299' to the Single value -1023.299.// Converted the Double value '-12.98' to the Single value -12.98.// Converted the Double value '0' to the Single value 0.// Converted the Double value '9.113E-16' to the Single value 9.113E-16.// Converted the Double value '103.919' to the Single value 103.919.// Converted the Double value '17834.191' to the Single value 17834.19.// Converted the Double value '1.79769313486232E+308' to the Single value Infinity.

Dim values() As Double = { Double.MinValue, -1.38e10, -1023.299, -12.98, _ 0, 9.113e-16, 103.919, 17834.191, Double.MaxValue }Dim result As SingleFor Each value As Double In values result = Convert.ToSingle(value) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ value.GetType().Name, value, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the Double value '-1.79769313486232E+308' to the Single value -Infinity.' Converted the Double value '-13800000000' to the Single value -1.38E+10.' Converted the Double value '-1023.299' to the Single value -1023.299.' Converted the Double value '-12.98' to the Single value -12.98.' Converted the Double value '0' to the Single value 0.' Converted the Double value '9.113E-16' to the Single value 9.113E-16.' Converted the Double value '103.919' to the Single value 103.919.' Converted the Double value '17834.191' to the Single value 17834.19.' Converted the Double value '1.79769313486232E+308' to the Single value Infinity.

另请参阅

• Double
• Round

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::Decimal value);

public static float ToSingle (decimal value);

static member ToSingle : decimal -> single

Public Shared Function ToSingle (value As Decimal) As Single

参数

返回

一个等于 value 的单精度浮点数。

使用“舍入为最接近的数字”规则对 value 进行舍入。 例如，当舍入为两位小数时，值 2.345 变成 2.34，而值 2.355 变成 2.36。

示例

以下示例将值数组 Decimal 中的每个元素转换为 Single 值。

decimal[] values = { Decimal.MinValue, -1034.23m, -12m, 0m, 147m, 199.55m, 9214.16m, Decimal.MaxValue };float result;foreach (var value in values){ result = Convert.ToSingle(value); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", value.GetType().Name, value, result.GetType().Name, result);}// The example displays the following output:// Converted the Decimal value '-79228162514264337593543950335' to the Single value -7.9228163E+28.// Converted the Decimal value '-1034.23' to the Single value -1034.23.// Converted the Decimal value '-12' to the Single value -12.// Converted the Decimal value '0' to the Single value 0.// Converted the Decimal value '147' to the Single value 147.// Converted the Decimal value '199.55' to the Single value 199.55.// Converted the Decimal value '9214.16' to the Single value 9214.16.// Converted the Decimal value '79228162514264337593543950335' to the Single value 7.9228163E+28.

let values = [| Decimal.MinValue; -1034.23m; -12m; 0m; 147m; 199.55m; 9214.16m; Decimal.MaxValue |]for value in values do let result = Convert.ToSingle value printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the Decimal value '-79228162514264337593543950335' to the Single value -7.9228163E+28.// Converted the Decimal value '-1034.23' to the Single value -1034.23.// Converted the Decimal value '-12' to the Single value -12.// Converted the Decimal value '0' to the Single value 0.// Converted the Decimal value '147' to the Single value 147.// Converted the Decimal value '199.55' to the Single value 199.55.// Converted the Decimal value '9214.16' to the Single value 9214.16.// Converted the Decimal value '79228162514264337593543950335' to the Single value 7.9228163E+28.

Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _ 199.55d, 9214.16d, Decimal.MaxValue }Dim result As SingleFor Each value As Decimal In values result = Convert.ToSingle(value) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ value.GetType().Name, value, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the Decimal value '-79228162514264337593543950335' to the Single value -7.922816E+28.' Converted the Decimal value '-1034.23' to the Single value -1034.23.' Converted the Decimal value '-12' to the Single value -12.' Converted the Decimal value '0' to the Single value 0.' Converted the Decimal value '147' to the Single value 147.' Converted the Decimal value '199.55' to the Single value 199.55.' Converted the Decimal value '9214.16' to the Single value 9214.16.' Converted the Decimal value '79228162514264337593543950335' to the Single value 7.922816E+28.

另请参阅

• Round

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(DateTime value);

public static float ToSingle (DateTime value);

static member ToSingle : DateTime -> single

Public Shared Function ToSingle (value As DateTime) As Single

参数

返回

不支持此转换。 不返回任何值。

例外

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(char value);

public static float ToSingle (char value);

static member ToSingle : char -> single

Public Shared Function ToSingle (value As Char) As Single

参数

返回

不支持此转换。 不返回任何值。

例外

另请参阅

• Char

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(System::Byte value);

public static float ToSingle (byte value);

static member ToSingle : byte -> single

Public Shared Function ToSingle (value As Byte) As Single

参数

返回

一个等于 value 的单精度浮点数。

示例

以下示例将字节值数组中的每个元素转换为 Single 值。

byte[] numbers = { Byte.MinValue, 10, 100, Byte.MaxValue };float result;foreach (byte number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the Byte value 0 to the Single value 0.// Converted the Byte value 10 to the Single value 10.// Converted the Byte value 100 to the Single value 100.// Converted the Byte value 255 to the Single value 255.

let numbers = [| Byte.MinValue; 10uy; 100uy; Byte.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the Byte value 0 to the Single value 0.// Converted the Byte value 10 to the Single value 10.// Converted the Byte value 100 to the Single value 100.// Converted the Byte value 255 to the Single value 255.

Dim numbers() As Byte = { Byte.MinValue, 10, 100, Byte.MaxValue }Dim result As SingleFor Each number As Byte In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result)Next' The example displays the following output:' Converted the Byte value 0 to the Single value 0.' Converted the Byte value 10 to the Single value 10.' Converted the Byte value 100 to the Single value 100.' Converted the Byte value 255 to the Single value 255.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(bool value);

public static float ToSingle (bool value);

static member ToSingle : bool -> single

Public Shared Function ToSingle (value As Boolean) As Single

参数

返回

如果 value 为 true，则为数字 1；否则，为 0。

示例

以下示例将布尔值 true 和 false 转换为 Single 值。

bool[] flags = { true, false };float result;foreach (bool flag in flags){ result = Convert.ToSingle(flag); Console.WriteLine("Converted {0} to {1}.", flag, result);}// The example displays the following output:// Converted True to 1.// Converted False to 0.

let flags = [| true; false |]for flag in flags do let result = Convert.ToSingle flag printfn $"Converted {flag} to {result}."// The example displays the following output:// Converted True to 1.// Converted False to 0.

Dim flags() As Boolean = { True, False }Dim result As SingleFor Each flag As Boolean In flags result = Convert.ToSingle(flag) Console.WriteLine("Converted {0} to {1}.", flag, result)Next' The example displays the following output:' Converted True to 1.' Converted False to 0.

Source:

Convert.cs

Source:

Convert.cs

Source:

Convert.cs

public: static float ToSingle(long value);

public static float ToSingle (long value);

static member ToSingle : int64 -> single

Public Shared Function ToSingle (value As Long) As Single

参数

返回

一个等于 value 的单精度浮点数。

示例

以下示例将长整数数组中的每个元素转换为 Single 值。

long[] numbers = { Int64.MinValue, -903, 0, 172, Int64.MaxValue};float result;foreach (long number in numbers){ result = Convert.ToSingle(number); Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", number.GetType().Name, number, result.GetType().Name, result);}// The example displays the following output:// Converted the Int64 value '-9223372036854775808' to the Single value -9.223372E+18.// Converted the Int64 value '-903' to the Single value -903.// Converted the Int64 value '0' to the Single value 0.// Converted the Int64 value '172' to the Single value 172.// Converted the Int64 value '9223372036854775807' to the Single value 9.223372E+18.

let numbers = [| Int64.MinValue; -903; 0; 172; Int64.MaxValue |]for number in numbers do let result = Convert.ToSingle number printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."// The example displays the following output:// Converted the Int64 value '-9223372036854775808' to the Single value -9.223372E+18.// Converted the Int64 value '-903' to the Single value -903.// Converted the Int64 value '0' to the Single value 0.// Converted the Int64 value '172' to the Single value 172.// Converted the Int64 value '9223372036854775807' to the Single value 9.223372E+18.

 Dim numbers() As Long = { Int64.MinValue, -903, 0, 172, Int64.MaxValue} Dim result As Single For Each number As Long In numbers result = Convert.ToSingle(number) Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _ number.GetType().Name, number, _ result.GetType().Name, result) Next ' The example displays the following output:Converted the Int64 value '-9223372036854775808' to the Single value -9.223372E+18.Converted the Int64 value '-903' to the Single value -903.Converted the Int64 value '0' to the Single value 0.Converted the Int64 value '172' to the Single value 172.Converted the Int64 value '9223372036854775807' to the Single value 9.223372E+18. ' Converted the Int64 value '-9223372036854775808' to the Single value -9.223372E+18. ' Converted the Int64 value '-903' to the Single value -903. ' Converted the Int64 value '0' to the Single value 0. ' Converted the Int64 value '172' to the Single value 172. ' Converted the Int64 value '9223372036854775807' to the Single value 9.223372E+18.