Enum.Parse 方法

定義

把一或多個列舉常數的名稱或數值的字串表示轉換為一個相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object.

多載

Parse(Type, String)

把一或多個列舉常數的名稱或數值的字串表示轉換為一個相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object.

Parse(Type, String, Boolean)

把一或多個列舉常數的名稱或數值的字串表示轉換為一個相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object. 參數會定義運算是否區分大小寫。A parameter specifies whether the operation is case-insensitive.

Parse<TEnum>(String, Boolean)

將一或多個列舉常數的名稱或數值字串表示 (由 TEnum 所指定) 轉換為相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants specified by TEnum to an equivalent enumerated object. 參數會定義運算是否區分大小寫。A parameter specifies whether the operation is case-insensitive.

Parse<TEnum>(String)

將一或多個列舉常數的名稱或數值字串表示 (由 TEnum 所指定) 轉換為相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants specified by TEnum to an equivalent enumerated object.

Parse(Type, String)

把一或多個列舉常數的名稱或數值的字串表示轉換為一個相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object.

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

參數

enumType
Type

列舉類型。An enumeration type.

value
String

字串,包含要轉換的名稱或數值。A string containing the name or value to convert.

傳回

enumType 類型的物件,其值以 value 表示。An object of type enumType whose value is represented by value.

屬性

例外狀況

enumTypevaluenullenumType or value is null.

enumType 不是 EnumenumType is not an Enum.

-或--or- value 為空字串 ("") 或只包含空格。value is either an empty string or only contains white space.

-或--or- value 為名稱,但不是為列舉所定義的其中一個具名常數。value is a name, but not one of the named constants defined for the enumeration.

value 超出 enumType 之基礎類型的範圍。value is outside the range of the underlying type of enumType.

範例

下列範例會使用 Parse(Type, String) 方法來剖析藉由呼叫 GetNames 方法所建立的字串陣列。The following example uses the Parse(Type, String) method to parse an array of strings that are created by calling the GetNames method. 它也會使用 Parse(Type, String) 方法來剖析包含位欄位的列舉值。It also uses the Parse(Type, String) method to parse an enumeration value that consists of a bit field.

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

*/
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
'

備註

value 參數包含列舉成員的基礎值或命名常數的字串表示,或是以逗號(,)分隔的已命名常數清單。The value parameter contains the string representation of an enumeration member's underlying value or named constant, or a list of named constants delimited by commas (,). 一或多個空格可以在 value中的每個值、名稱或逗號之前或後面。One or more blank spaces can precede or follow each value, name, or comma in value. 如果 value 是清單,則傳回值會是與位 OR 運算結合的指定名稱值。If value is a list, the return value is the value of the specified names combined with a bitwise OR operation.

如果 value 是未對應至 enumType之已命名常數的名稱,則方法會擲回 ArgumentExceptionIf value is a name that does not correspond to a named constant of enumType, the method throws an ArgumentException. 如果 value 是整數的字串表示,而不代表 enumType 列舉的基礎值,則此方法會傳回其基礎值 value 轉換成整數類資料類型的列舉成員。If value is the string representation of an integer that does not represent an underlying value of the enumType enumeration, the method returns an enumeration member whose underlying value is value converted to an integral type. 如果不想要此行為,請呼叫 IsDefined 方法,以確保整數的特定字串表示確實是 enumType的成員。If this behavior is undesirable, call the IsDefined method to ensure that a particular string representation of an integer is actually a member of enumType. 下列範例會定義 Colors 列舉,並呼叫 Parse(Type, String) 方法,將字串轉換為其對應的列舉值,並呼叫 IsDefined 方法,以確保特定整數值是 Colors 列舉中的基礎值。The following example defines a Colors enumeration, calls the Parse(Type, String) method to convert strings to their corresponding enumeration values, and calls the IsDefined method to ensure that particular integral values are underlying values in the Colors enumeration.

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.
<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.

這是區分大小寫的作業。This operation is case-sensitive.

另請參閱

Parse(Type, String, Boolean)

把一或多個列舉常數的名稱或數值的字串表示轉換為一個相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants to an equivalent enumerated object. 參數會定義運算是否區分大小寫。A parameter specifies whether the operation is case-insensitive.

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

參數

enumType
Type

列舉類型。An enumeration type.

value
String

字串,包含要轉換的名稱或數值。A string containing the name or value to convert.

ignoreCase
Boolean

true 表示忽略大小寫,false 表示區分大小寫。true to ignore case; false to regard case.

傳回

enumType 類型的物件,其值以 value 表示。An object of type enumType whose value is represented by value.

屬性

例外狀況

enumTypevaluenullenumType or value is null.

enumType 不是 EnumenumType is not an Enum.

-或--or- value 為空字串 ("") 或只包含空格。value is either an empty string ("") or only contains white space.

-或--or- value 為名稱,但不是為列舉所定義的其中一個具名常數。value is a name, but not one of the named constants defined for the enumeration.

value 超出 enumType 之基礎類型的範圍。value is outside the range of the underlying type of enumType.

範例

下列範例會使用 Parse(Type, String, Boolean) 方法來剖析藉由呼叫 GetNames 方法所建立的字串陣列。The following example uses the Parse(Type, String, Boolean) method to parse an array of strings that are created by calling the GetNames method. 它也會使用 Parse(Type, String) 方法來剖析包含位欄位的列舉值。It also uses the Parse(Type, String) method to parse an enumeration value that consists of a bit field.

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.
<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.

備註

value 參數包含列舉成員的基礎值或命名常數的字串表示,或是以逗號(,)分隔的已命名常數清單。The value parameter contains the string representation of an enumeration member's underlying value or named constant, or a list of named constants delimited by commas (,). 一或多個空格可以在 value中的每個值、名稱或逗號之前或後面。One or more blank spaces can precede or follow each value, name, or comma in value. 如果 value 是清單,則傳回值會是與位 OR 運算結合的指定名稱值。If value is a list, the return value is the value of the specified names combined with a bitwise OR operation.

如果 value 是未對應至 enumType之已命名常數的名稱,則方法會擲回 ArgumentExceptionIf value is a name that does not correspond to a named constant of enumType, the method throws an ArgumentException. 如果 value 是整數的字串表示,而不代表 enumType 列舉的基礎值,則此方法會傳回其基礎值 value 轉換成整數類資料類型的列舉成員。If value is the string representation of an integer that does not represent an underlying value of the enumType enumeration, the method returns an enumeration member whose underlying value is value converted to an integral type. 如果不想要此行為,請呼叫 IsDefined 方法,以確保整數的特定字串表示確實是 enumType的成員。If this behavior is undesirable, call the IsDefined method to ensure that a particular string representation of an integer is actually a member of enumType. 下列範例會定義 Colors 列舉,並呼叫 Parse(Type, String, Boolean) 方法,將字串轉換為其對應的列舉值,並呼叫 IsDefined 方法,以確保特定整數值是 Colors 列舉中的基礎值。The following example defines a Colors enumeration, calls the Parse(Type, String, Boolean) method to convert strings to their corresponding enumeration values, and calls the IsDefined method to ensure that particular integral values are underlying values in the Colors enumeration.

ignoreCase 參數會指定此作業是否區分大小寫。The ignoreCase parameter specifies whether this operation is case-sensitive.

另請參閱

Parse<TEnum>(String, Boolean)

將一或多個列舉常數的名稱或數值字串表示 (由 TEnum 所指定) 轉換為相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants specified by TEnum to an equivalent enumerated object. 參數會定義運算是否區分大小寫。A parameter specifies whether the operation is case-insensitive.

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

類型參數

TEnum

列舉類型。An enumeration type.

參數

value
String

字串,包含要轉換的名稱或數值。A string containing the name or value to convert.

ignoreCase
Boolean

true 表示忽略大小寫,false 表示區分大小寫。true to ignore case; false to regard case.

傳回

TEnum

TEnum 類型的物件,其值以 value 表示。An object of type TEnum whose value is represented by value.

例外狀況

TEnum 不是 Enum 類型。TEnum is not an Enum type.

valuenullvalue is null.

value 不包含列舉資訊。value does not contain enumeration information.

Parse<TEnum>(String)

將一或多個列舉常數的名稱或數值字串表示 (由 TEnum 所指定) 轉換為相等列舉物件。Converts the string representation of the name or numeric value of one or more enumerated constants specified by TEnum to an equivalent enumerated object.

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

類型參數

TEnum

列舉類型。An enumeration type.

參數

value
String

字串,包含要轉換的名稱或數值。A string containing the name or value to convert.

傳回

TEnum

TEnum 類型的物件,其值以 value 表示。An object of type TEnum whose value is represented by value.

例外狀況

TEnum 不是 Enum 類型。TEnum is not an Enum type.

valuenullvalue is null.

value 不包含列舉資訊。value does not contain enumeration information.

適用於