ConvertEventArgs.DesiredType 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

取得您要的值的資料類型。

public:
 property Type ^ DesiredType { Type ^ get(); };

public Type? DesiredType { get; }

member this.DesiredType : Type

Public ReadOnly Property DesiredType As Type

屬性值

Type

您要的值的 Type。

範例

下列程式碼範例會 DesiredType 使用 屬性來判斷某個類型的轉換是否可以繼續。 方法會 DecimalToCurrencyString 測試 是否 DesiredType 為字串。 如果沒有，程式碼會結束 方法。 同樣地，方法會 CurrencyStringToDecimal 測試 是否 DesiredType 為 Decimal ，如果 不是 true ，則會結束。

private:
   void DecimalToCurrencyString( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      // The method converts only to string type. 
      if ( cevent->DesiredType != String::typeid )
      {
         return;
      }

      cevent->Value = ( (Decimal^)(cevent->Value) )->ToString( "c" );
   }

   void CurrencyStringToDecimal( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      // The method converts only to decimal type.
      if ( cevent->DesiredType != Decimal::typeid )
      {
         return;
      }

      cevent->Value = Decimal::Parse( cevent->Value->ToString(),
         NumberStyles::Currency, nullptr );
   }

private void DecimalToCurrencyString(object sender, ConvertEventArgs cevent)
{
   // The method converts only to string type. 
   if(cevent.DesiredType != typeof(string)) return;

   cevent.Value = ((decimal) cevent.Value).ToString("c");
}

private void CurrencyStringToDecimal(object sender, ConvertEventArgs cevent)
{   
   // The method converts only to decimal type.
   if(cevent.DesiredType != typeof(decimal)) return;

   cevent.Value = Decimal.Parse(cevent.Value.ToString(),
   NumberStyles.Currency, null);
}

Private Sub DecimalToCurrencyString(sender As Object, cevent As ConvertEventArgs)
   ' The method converts only to string type. 
   If cevent.DesiredType IsNot GetType(String) Then
      Return
   End If 
   cevent.Value = CDec(cevent.Value).ToString("c")
End Sub 
 
 
Private Sub CurrencyStringToDecimal(sender As Object, cevent As ConvertEventArgs)
   ' The method converts only to decimal type.
   If cevent.DesiredType IsNot GetType(Decimal) Then
      Return
   End If 
 cevent.Value = Decimal.Parse(cevent.Value.ToString, _
 NumberStyles.Currency, nothing)
End Sub

備註

屬性 DesiredType 可讓您檢查要轉換值的屬性類型。