Enum.TryParse メソッド

public:
 static bool TryParse(Type ^ enumType, System::String ^ value, [Runtime::InteropServices::Out] System::Object ^ % result);

public static bool TryParse (Type enumType, string? value, out object? result);

public static bool TryParse (Type enumType, string value, out object result);

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

Public Shared Function TryParse (enumType As Type, value As String, ByRef result As Object) As Boolean

パラメーター

戻り値

Boolean

変換が成功した場合は true。それ以外の場合は false。true if the conversion succeeded; false otherwise.

public:
 static bool TryParse(Type ^ enumType, System::String ^ value, bool ignoreCase, [Runtime::InteropServices::Out] System::Object ^ % result);

public static bool TryParse (Type enumType, string? value, bool ignoreCase, out object? result);

public static bool TryParse (Type enumType, string value, bool ignoreCase, out object result);

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

Public Shared Function TryParse (enumType As Type, value As String, ignoreCase As Boolean, ByRef result As Object) As Boolean

パラメーター

戻り値

Boolean

変換が成功した場合は true。それ以外の場合は false。true if the conversion succeeded; false otherwise.

public:
generic <typename TEnum>
 where TEnum : value class static bool TryParse(System::String ^ value, bool ignoreCase, [Runtime::InteropServices::Out] TEnum % result);

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

public static bool TryParse<TEnum> (string? value, bool ignoreCase, out TEnum result) where TEnum : struct;

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

Public Shared Function TryParse(Of TEnum As Structure) (value As String, ignoreCase As Boolean, ByRef result As TEnum) As Boolean

型パラメーター

パラメーター

戻り値

Boolean

value パラメーターが正常に変換された場合は true。それ以外の場合は false。true if the value parameter was converted successfully; otherwise, false.

例外

例

次の例では、Colors列挙体を定義し、TryParse<TEnum>(String, Boolean, TEnum)メソッドを呼び出して文字列を対応する列挙値に変換し、IsDefinedメソッドを呼び出して、特定の整数値がColors列挙体の基になる値であることを確認します。The following example defines a Colors enumeration, calls the TryParse<TEnum>(String, Boolean, TEnum) 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. TryParse<TEnum>(String, Boolean, TEnum)メソッドは、名前付き定数の文字列形式を等価の列挙値に変換しようとしたときに、大文字と小文字を区別しない比較を使用します。The TryParse<TEnum>(String, Boolean, TEnum) method uses case-insensitive comparison when trying to convert the string representations of named constants to their equivalent enumeration values.

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)
      {
         Colors colorValue;
         if (Enum.TryParse(colorString, true, out colorValue))
            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);
         else
            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
         Dim colorValue As Colors
         If [Enum].TryParse(colorString, True, colorValue) Then        
            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                    
         Else
            Console.WriteLine("{0} is not a member of the Colors enumeration.", colorString)
         End If
      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.

注釈

TryParse<TEnum>(String, Boolean, TEnum)はParse(Type, String, Boolean)メソッドと同じですが、例外をスローするのではなく、変換に失敗した場合はfalseを返します。TryParse<TEnum>(String, Boolean, TEnum) is identical to the Parse(Type, String, Boolean) method, except that instead of throwing an exception, it returns false if the conversion fails. これにより、列挙値の文字列形式を解析するときに例外処理を行う必要がなくなります。It eliminates the need for exception handling when parsing the string representation of an enumeration value.

valueパラメーターには、列挙メンバーの基になる値または名前付き定数の文字列形式、またはコンマ (,) で区切られた名前付き定数または基になる値のリストが含まれます。The value parameter contains the string representation of an enumeration member's underlying value or named constant, or a list of named constants or underlying values delimited by commas (,). valueに複数の名前付き定数または値が含まれている場合は、valueの各値、名前、またはコンマの前または後に 1 つ以上の空白文字を含めることができます。If value includes multiple named constants or values, one or more blank spaces can precede or follow each value, name, or comma in value. valueがリストの場合、resultは、指定された名前または基になる値を、ビットごとにOR演算で組み合わせた値となります。If value is a list, result reflects the value of the specified names or underlying values combined with a bitwise OR operation. valueが列挙値の名前の文字列表現である場合、 value と列挙名の比較はパラメーターによって異なり ignoreCase ます。If value is the string representation of the name of an enumeration value, the comparison of value with enumeration names depends on the ignoreCase parameter. の場合、 true 比較では大文字と小文字が区別されません。の場合は、 false 大文字と小文字が区別されます。If true, the comparison is case-insensitive; if false, it is case-sensitive.

valueがTEnumの名前付き定数に対応しない名前である場合、メソッドはfalseを返します。If value is a name that does not correspond to a named constant of TEnum, the method returns false. valueがTEnum列挙体の基になる値を表さない整数の文字列表現の場合、メソッドは、基になる値が整数型に変換されたvalueである列挙体のメンバーを返します。If value is the string representation of an integer that does not represent an underlying value of the TEnum enumeration, the method returns an enumeration member whose underlying value is value converted to an integral type. この動作が望ましくない場合は、IsDefinedメソッドを呼び出して、整数の特定の文字列形式が実際にTEnumのメンバーであることを確認します。 If this behavior is undesirable, call the IsDefined method to ensure that a particular string representation of an integer is actually a member of TEnum.

こちらもご覧ください

• Parse(Type, String, Boolean)

public:
generic <typename TEnum>
 where TEnum : value class static bool TryParse(System::String ^ value, [Runtime::InteropServices::Out] TEnum % result);

public static bool TryParse<TEnum> (string value, out TEnum result) where TEnum : struct;

public static bool TryParse<TEnum> (string? value, out TEnum result) where TEnum : struct;

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

Public Shared Function TryParse(Of TEnum As Structure) (value As String, ByRef result As TEnum) As Boolean

型パラメーター

パラメーター

戻り値

Boolean

value パラメーターが正常に変換された場合は true。それ以外の場合は false。true if the value parameter was converted successfully; otherwise, false.

例外

例

次の例では、Colors列挙体を定義し、TryParse<TEnum>(String, TEnum)メソッドを呼び出して文字列を対応する列挙値に変換し、IsDefinedメソッドを呼び出して、特定の整数値がColors列挙体の基になる値であることを確認します。The following example defines a Colors enumeration, calls the TryParse<TEnum>(String, TEnum) 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)
      {
         Colors colorValue;
         if (Enum.TryParse(colorString, out colorValue))
            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);
         else
            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
         Dim colorValue As Colors
         If [Enum].TryParse(colorString, colorValue) Then        
            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                    
         Else
            Console.WriteLine("{0} is not a member of the Colors enumeration.", colorString)
         End If
      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.

注釈

TryParse<TEnum>(String, TEnum)はParse(Type, String)メソッドと同じですが、例外をスローするのではなく、変換に失敗した場合はfalseを返します。TryParse<TEnum>(String, TEnum) is identical to the Parse(Type, String) method, except that instead of throwing an exception, it returns false if the conversion fails. これにより、列挙値の文字列形式を解析するときに例外処理を行う必要がなくなります。It eliminates the need for exception handling when parsing the string representation of an enumeration value.

valueパラメーターには、列挙メンバーの基になる値または名前付き定数の文字列形式、またはコンマ (,) で区切られた名前付き定数または基になる値のリストが含まれます。The value parameter contains the string representation of an enumeration member's underlying value or named constant, or a list of named constants or underlying values delimited by commas (,). valueに複数の名前付き定数または値が含まれている場合は、valueの各値、名前、またはコンマの前または後に 1 つ以上の空白文字を含めることができます。If value includes multiple named constants or values, one or more blank spaces can precede or follow each value, name, or comma in value. valueがリストの場合、resultは、指定された名前または基になる値を、ビットごとにOR演算で組み合わせた値となります。If value is a list, result reflects the value of the specified names or underlying values combined with a bitwise OR operation. valueが列挙値の名前の文字列表現である場合、valueと列挙型の比較では大文字と小文字が区別されます。If value is the string representation of the name of an enumeration value, the comparison of value with enumeration names is case-sensitive.

valueがTEnumの名前付き定数に対応しない名前である場合、メソッドはfalseを返します。If value is a name that does not correspond to a named constant of TEnum, the method returns false. valueがTEnum列挙体の基になる値を表さない整数の文字列表現の場合、メソッドは、基になる値が整数型に変換されたvalueである列挙体のメンバーを返します。If value is the string representation of an integer that does not represent an underlying value of the TEnum enumeration, the method returns an enumeration member whose underlying value is value converted to an integral type. この動作が望ましくない場合は、IsDefinedメソッドを呼び出して、整数の特定の文字列形式が実際にTEnumのメンバーであることを確認します。 If this behavior is undesirable, call the IsDefined method to ensure that a particular string representation of an integer is actually a member of TEnum.

こちらもご覧ください

• Parse(Type, String)