Enum.Parse 方法

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
 static System::Object ^ Parse(Type ^ enumType, ReadOnlySpan<char> value);

public static object Parse (Type enumType, ReadOnlySpan<char> value);

static member Parse : Type * ReadOnlySpan<char> -> obj

Public Shared Function Parse (enumType As Type, value As ReadOnlySpan(Of Char)) As Object

参数

返回

类型 enumType 的对象，其值由 value表示。

例外

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
 static System::Object ^ Parse(Type ^ enumType, System::String ^ value);

public static object Parse (Type enumType, string value);

[System.Runtime.InteropServices.ComVisible(true)]
public static object Parse (Type enumType, string value);

static member Parse : Type * string -> obj

[<System.Runtime.InteropServices.ComVisible(true)>]
static member Parse : Type * string -> obj

Public Shared Function Parse (enumType As Type, value As String) As Object

参数

返回

类型 enumType 的对象，其值由 value表示。

属性

ComVisibleAttribute

例外

示例

以下示例使用 Parse(Type, String) 方法分析通过调用 GetNames 方法创建的字符串数组。 它还使用 Parse(Type, String) 方法分析由位字段组成的枚举值。

using namespace System;

[Flags]
enum class Colors
{
   Red = 1,
   Green = 2,
   Blue = 4,
   Yellow = 8
};

int main()
{
   Console::WriteLine(  "The entries of the Colors enumeration are:" );
   Array^ a = Enum::GetNames( Colors::typeid );
   Int32 i = 0;
   while ( i < a->Length )
   {
      Object^ o = a->GetValue( i );
      Console::WriteLine( o->ToString() );
      i++;
   }

   Console::WriteLine();
   Object^ orange = Enum::Parse( Colors::typeid,  "Red, Yellow" );
   Console::WriteLine("The orange value has the combined entries of {0}", orange );
}

/*
This code example produces the following results:

The entries of the Colors Enum are:
Red
Green
Blue
Yellow

The orange value has the combined entries of Red, Yellow

*/

using System;

public class ParseTest
{
    [Flags]
    enum Colors { Red = 1, Green = 2, Blue = 4, Yellow = 8 };

    public static void Main()
    {
        Console.WriteLine("The entries of the Colors enumeration are:");
        foreach (string colorName in Enum.GetNames(typeof(Colors)))
        {
            Console.WriteLine("{0} = {1:D}", colorName,
                                         Enum.Parse(typeof(Colors), colorName));
        }
        Console.WriteLine();

        Colors orange = (Colors) Enum.Parse(typeof(Colors), "Red, Yellow");
        Console.WriteLine("The orange value {0:D} has the combined entries of {0}",
                           orange);
    }
}

/*
This code example produces the following results:

The entries of the Colors Enum are:
Red = 1
Green = 2
Blue = 4
Yellow = 8

The orange value 9 has the combined entries of Red, Yellow

*/

open System

[<Flags>]
type Colors =
    | Red = 1
    | Green = 2
    | Blue = 4
    | Yellow = 8

printfn "The entries of the Colors enumeration are:"
for colorName in Enum.GetNames typeof<Colors> do
    printfn $"{colorName} = {Enum.Parse(typeof<Colors>, colorName):D}"
printfn ""

let orange = Enum.Parse(typeof<Colors>, "Red, Yellow") :?> Colors
printfn $"The orange value {orange:D} has the combined entries of {orange}"

// This code example produces the following results:
//     The entries of the Colors Enum are:
//     Red = 1
//     Green = 2
//     Blue = 4
//     Yellow = 8
//    
//     The orange value 9 has the combined entries of Red, Yellow

Public Class ParseTest

    <Flags()> _
    Enum Colors
        Red = 1
        Green = 2
        Blue = 4
        Yellow = 8
    End Enum

    Public Shared Sub Main()
        Console.WriteLine("The entries of the Colors enumeration are:")
        Dim colorName As String
        For Each colorName In [Enum].GetNames(GetType(Colors))
            Console.WriteLine("{0} = {1:D}", colorName, [Enum].Parse(GetType(Colors), colorName))
        Next
        Console.WriteLine()

        Dim orange As Colors = CType([Enum].Parse(GetType(Colors), "Red, Yellow"), Colors)
        Console.WriteLine("The orange value {0:D} has the combined entries of {0}", orange)
    End Sub
End Class

'This example displays the following output:
'
'The entries of the Colors Enum are:
'Red = 1
'Green = 2
'Blue = 4
'Yellow = 8
'
'The myOrange value 9 has the combined entries of Red, Yellow
'

注解

value 参数包含枚举成员的基础值或命名常量的字符串表示形式，或用逗号（，）分隔的命名常量列表。 一个或多个空格可以位于 value中的每个值、名称或逗号前面或后面。 如果 value 是列表，则返回值是指定名称的值，并结合按位 OR 操作。

如果 value 的名称与 enumType的命名常量不对应，该方法将引发 ArgumentException。 如果 value 是一个不表示 enumType 枚举的基础值的整数的字符串表示形式，该方法将返回一个枚举成员，其基础值 value 转换为整型类型。 如果此行为不可取，请调用 IsDefined 方法以确保整数的特定字符串表示形式实际上是 enumType的成员。 以下示例定义一个 Colors 枚举，调用 Parse(Type, String) 方法将字符串转换为其相应的枚举值，并调用 IsDefined 方法以确保特定整型值是 Colors 枚举中的基础值。

using System;

[Flags] enum Colors { None=0, Red = 1, Green = 2, Blue = 4 };

public class Example
{
   public static void Main()
   {
      string[] colorStrings = { "0", "2", "8", "blue", "Blue", "Yellow", "Red, Green" };
      foreach (string colorString in colorStrings)
      {
         try {
            Colors colorValue = (Colors) Enum.Parse(typeof(Colors), colorString);
            if (Enum.IsDefined(typeof(Colors), colorValue) | colorValue.ToString().Contains(","))
               Console.WriteLine("Converted '{0}' to {1}.", colorString, colorValue.ToString());
            else
               Console.WriteLine("{0} is not an underlying value of the Colors enumeration.", colorString);
         }
         catch (ArgumentException) {
            Console.WriteLine("'{0}' is not a member of the Colors enumeration.", colorString);
         }
      }
   }
}
// The example displays the following output:
//       Converted '0' to None.
//       Converted '2' to Green.
//       8 is not an underlying value of the Colors enumeration.
//       'blue' is not a member of the Colors enumeration.
//       Converted 'Blue' to Blue.
//       'Yellow' is not a member of the Colors enumeration.
//       Converted 'Red, Green' to Red, Green.

open System

[<Flags>]
type Colors =
    | None = 0
    | Red = 1
    | Green = 2
    | Blue = 4

let colorStrings = [ "0"; "2"; "8"; "blue"; "Blue"; "Yellow"; "Red, Green" ]
for colorString in colorStrings do
    try
        let colorValue = Enum.Parse(typeof<Colors>, colorString) :?> Colors
        if Enum.IsDefined(typeof<Colors>, colorValue) || (string colorValue).Contains "," then
            printfn $"Converted '{colorString}' to {colorValue}."
        else
            printfn $"{colorString} is not an underlying value of the Colors enumeration."
    with :? ArgumentException ->
        printfn $"'{colorString}' is not a member of the Colors enumeration."
// The example displays the following output:
//       Converted '0' to None.
//       Converted '2' to Green.
//       8 is not an underlying value of the Colors enumeration.
//       'blue' is not a member of the Colors enumeration.
//       Converted 'Blue' to Blue.
//       'Yellow' is not a member of the Colors enumeration.
//       Converted 'Red, Green' to Red, Green.

<Flags> Enum Colors As Integer
   None = 0
   Red = 1
   Green = 2
   Blue = 4
End Enum

Module Example
   Public Sub Main()
      Dim colorStrings() As String = {"0", "2", "8", "blue", "Blue", "Yellow", "Red, Green"}
      For Each colorString As String In colorStrings
         Try
            Dim colorValue As Colors = CType([Enum].Parse(GetType(Colors), colorString), Colors)        
            If [Enum].IsDefined(GetType(Colors), colorValue) Or colorValue.ToString().Contains(",") Then 
               Console.WriteLine("Converted '{0}' to {1}.", colorString, colorValue.ToString())
            Else
               Console.WriteLine("{0} is not an underlying value of the Colors enumeration.", colorString)            
            End If                    
         Catch e As ArgumentException
            Console.WriteLine("'{0}' is not a member of the Colors enumeration.", colorString)
         End Try
      Next
   End Sub
End Module
' The example displays the following output:
'       Converted '0' to None.
'       Converted '2' to Green.
'       8 is not an underlying value of the Colors enumeration.
'       'blue' is not a member of the Colors enumeration.
'       Converted 'Blue' to Blue.
'       'Yellow' is not a member of the Colors enumeration.
'       Converted 'Red, Green' to Red, Green.

此操作区分大小写。

另请参阅

• IsDefined(Type, Object)

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
 static System::Object ^ Parse(Type ^ enumType, ReadOnlySpan<char> value, bool ignoreCase);

public static object Parse (Type enumType, ReadOnlySpan<char> value, bool ignoreCase);

static member Parse : Type * ReadOnlySpan<char> * bool -> obj

Public Shared Function Parse (enumType As Type, value As ReadOnlySpan(Of Char), ignoreCase As Boolean) As Object

参数

返回

类型 enumType 的对象，其值由 value表示。

例外

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
 static System::Object ^ Parse(Type ^ enumType, System::String ^ value, bool ignoreCase);

public static object Parse (Type enumType, string value, bool ignoreCase);

[System.Runtime.InteropServices.ComVisible(true)]
public static object Parse (Type enumType, string value, bool ignoreCase);

static member Parse : Type * string * bool -> obj

[<System.Runtime.InteropServices.ComVisible(true)>]
static member Parse : Type * string * bool -> obj

Public Shared Function Parse (enumType As Type, value As String, ignoreCase As Boolean) As Object

参数

返回

类型 enumType 的对象，其值由 value表示。

属性

ComVisibleAttribute

例外

示例

以下示例使用 Parse(Type, String, Boolean) 方法分析通过调用 GetNames 方法创建的字符串数组。 它还使用 Parse(Type, String) 方法分析由位字段组成的枚举值。

using System;

[Flags] enum Colors { None=0, Red = 1, Green = 2, Blue = 4 };

public class Example
{
   public static void Main()
   {
      string[] colorStrings = { "0", "2", "8", "blue", "Blue", "Yellow", "Red, Green" };
      foreach (string colorString in colorStrings)
      {
         try {
            Colors colorValue = (Colors) Enum.Parse(typeof(Colors), colorString, true);
            if (Enum.IsDefined(typeof(Colors), colorValue) | colorValue.ToString().Contains(","))
               Console.WriteLine("Converted '{0}' to {1}.", colorString, colorValue.ToString());
            else
               Console.WriteLine("{0} is not an underlying value of the Colors enumeration.", colorString);
         }
         catch (ArgumentException) {
            Console.WriteLine("{0} is not a member of the Colors enumeration.", colorString);
         }
      }
   }
}
// The example displays the following output:
//       Converted '0' to None.
//       Converted '2' to Green.
//       8 is not an underlying value of the Colors enumeration.
//       Converted 'blue' to Blue.
//       Converted 'Blue' to Blue.
//       Yellow is not a member of the Colors enumeration.
//       Converted 'Red, Green' to Red, Green.

open System

[<Flags>]
type Colors =
    | None = 0
    | Red = 1
    | Green = 2
    | Blue = 4

let colorStrings = [ "0"; "2"; "8"; "blue"; "Blue"; "Yellow"; "Red, Green" ]
for colorString in colorStrings do
    try
        let colorValue = Enum.Parse(typeof<Colors>, colorString, true) :?> Colors
        if Enum.IsDefined(typeof<Colors>, colorValue) || (string colorValue).Contains "," then
            printfn $"Converted '{colorString}' to {colorValue}."
        else
            printfn $"{colorString} is not an underlying value of the Colors enumeration."
    with :? ArgumentException ->
        printfn $"{colorString} is not a member of the Colors enumeration."

// The example displays the following output:
//       Converted '0' to None.
//       Converted '2' to Green.
//       8 is not an underlying value of the Colors enumeration.
//       Converted 'blue' to Blue.
//       Converted 'Blue' to Blue.
//       Yellow is not a member of the Colors enumeration.
//       Converted 'Red, Green' to Red, Green.

<Flags> Enum Colors As Integer
   None = 0
   Red = 1
   Green = 2
   Blue = 4
End Enum

Module Example
   Public Sub Main()
      Dim colorStrings() As String = {"0", "2", "8", "blue", "Blue", "Yellow", "Red, Green"}
      For Each colorString As String In colorStrings
         Try
            Dim colorValue As Colors = CType([Enum].Parse(GetType(Colors), colorString, True), Colors)        
            If [Enum].IsDefined(GetType(Colors), colorValue) Or colorValue.ToString().Contains(",") Then 
               Console.WriteLine("Converted '{0}' to {1}.", colorString, colorValue.ToString())
            Else
               Console.WriteLine("{0} is not an underlying value of the Colors enumeration.", colorString)            
            End If                    
         Catch e As ArgumentException
            Console.WriteLine("{0} is not a member of the Colors enumeration.", colorString)
         End Try
      Next
   End Sub
End Module
' The example displays the following output:
'       Converted '0' to None.
'       Converted '2' to Green.
'       8 is not an underlying value of the Colors enumeration.
'       Converted 'blue' to Blue.
'       Converted 'Blue' to Blue.
'       Yellow is not a member of the Colors enumeration.
'       Converted 'Red, Green' to Red, Green.

注解

value 参数包含枚举成员的基础值或命名常量的字符串表示形式，或用逗号（，）分隔的命名常量列表。 一个或多个空格可以位于 value中的每个值、名称或逗号前面或后面。 如果 value 是列表，则返回值是指定名称的值，并结合按位 OR 操作。

如果 value 的名称与 enumType的命名常量不对应，该方法将引发 ArgumentException。 如果 value 是一个不表示 enumType 枚举的基础值的整数的字符串表示形式，该方法将返回一个枚举成员，其基础值 value 转换为整型类型。 如果此行为不可取，请调用 IsDefined 方法以确保整数的特定字符串表示形式实际上是 enumType的成员。 以下示例定义一个 Colors 枚举，调用 Parse(Type, String, Boolean) 方法将字符串转换为其相应的枚举值，并调用 IsDefined 方法以确保特定整型值是 Colors 枚举中的基础值。

ignoreCase 参数指定此操作是否区分大小写。

另请参阅

• IsDefined(Type, Object)

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
generic <typename TEnum>
 where TEnum : value class static TEnum Parse(System::String ^ value, bool ignoreCase);

public static TEnum Parse<TEnum> (string value, bool ignoreCase) where TEnum : struct;

static member Parse : string * bool -> 'Enum (requires 'Enum : struct)

Public Shared Function Parse(Of TEnum As Structure) (value As String, ignoreCase As Boolean) As TEnum

类型参数

参数

返回

类型 TEnum 的对象，其值由 value表示。

例外

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
generic <typename TEnum>
 where TEnum : value class static TEnum Parse(ReadOnlySpan<char> value, bool ignoreCase);

public static TEnum Parse<TEnum> (ReadOnlySpan<char> value, bool ignoreCase) where TEnum : struct;

static member Parse : ReadOnlySpan<char> * bool -> 'Enum (requires 'Enum : struct)

Public Shared Function Parse(Of TEnum As Structure) (value As ReadOnlySpan(Of Char), ignoreCase As Boolean) As TEnum

类型参数

参数

返回

TEnum 一个类型 TEnum 的对象，其值由 value表示。

例外

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
generic <typename TEnum>
 where TEnum : value class static TEnum Parse(ReadOnlySpan<char> value);

public static TEnum Parse<TEnum> (ReadOnlySpan<char> value) where TEnum : struct;

static member Parse : ReadOnlySpan<char> -> 'Enum (requires 'Enum : struct)

Public Shared Function Parse(Of TEnum As Structure) (value As ReadOnlySpan(Of Char)) As TEnum

类型参数

参数

返回

TEnum 一个类型 TEnum 的对象，其值由 value表示。

例外

Source:

Enum.cs

Source:

Enum.cs

Source:

Enum.cs

public:
generic <typename TEnum>
 where TEnum : value class static TEnum Parse(System::String ^ value);

public static TEnum Parse<TEnum> (string value) where TEnum : struct;

static member Parse : string -> 'Enum (requires 'Enum : struct)

Public Shared Function Parse(Of TEnum As Structure) (value As String) As TEnum

类型参数

参数

返回

类型 TEnum 的对象，其值由 value表示。

例外