Binding.Parse Kejadian

Definisi

Ruang nama:

System.Windows.Forms

Rakitan:

System.Windows.Forms.dll

Terjadi ketika nilai kontrol terikat data berubah.

public:
 event System::Windows::Forms::ConvertEventHandler ^ Parse;

public event System.Windows.Forms.ConvertEventHandler Parse;

member this.Parse : System.Windows.Forms.ConvertEventHandler 

Public Custom Event Parse As ConvertEventHandler 

Jenis Acara

ConvertEventHandler

Contoh

Contoh kode berikut membuat Binding, menambahkan ConvertEventHandler delegasi ke Parse peristiwa dan Format , dan menambahkan Binding ke BindingsCollection kontrol TextBox melalui DataBindings properti . Delegasi DecimalToCurrencyString peristiwa, ditambahkan ke Format peristiwa, memformat nilai terikat ( Decimal jenis) sebagai mata uang menggunakan ToString metode . Delegasi CurrencyStringToDecimal peristiwa, ditambahkan ke Parse peristiwa, mengonversi nilai yang ditampilkan oleh kontrol kembali ke Decimal jenis .

private:
   void DecimalToCurrencyString( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      // The method converts only to string type. Test this using the DesiredType.
      if ( cevent->DesiredType != String::typeid )
      {
         return;
      }
      
      // Use the ToString method to format the value as currency ("c").
      cevent->Value = ( (Decimal)(cevent->Value) ).ToString( "c" );
   }

   void CurrencyStringToDecimal( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      // The method converts back to decimal type only.
      if ( cevent->DesiredType != Decimal::typeid )
      {
         return;
      }
      
      // Converts the string back to decimal using the static Parse method.
      cevent->Value = Decimal::Parse( cevent->Value->ToString(),
         NumberStyles::Currency, nullptr );
   }

   void BindControl()
   {
      // Creates the binding first. The OrderAmount is typed as Decimal.
      Binding^ b = gcnew Binding(
         "Text", ds, "customers.custToOrders.OrderAmount" );
      // Add the delegates to the event.
      b->Format += gcnew ConvertEventHandler( this, &Form1::DecimalToCurrencyString );
      b->Parse += gcnew ConvertEventHandler( this, &Form1::CurrencyStringToDecimal );
      text1->DataBindings->Add( b );
   }

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

   // Use the ToString method to format the value as currency ("c").
   cevent.Value = ((decimal) cevent.Value).ToString("c");
}

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

   // Converts the string back to decimal using the static Parse method.
   cevent.Value = Decimal.Parse(cevent.Value.ToString(),
   NumberStyles.Currency, null);
}

private void BindControl()
{
   // Creates the binding first. The OrderAmount is typed as Decimal.
   Binding b = new Binding
      ("Text", ds, "customers.custToOrders.OrderAmount");
   // Add the delegates to the event.
   b.Format += new ConvertEventHandler(DecimalToCurrencyString);
   b.Parse += new ConvertEventHandler(CurrencyStringToDecimal);
   text1.DataBindings.Add(b);
}

Private Sub DecimalToCurrencyString(sender As Object, cevent As ConvertEventArgs)
    ' The method converts only to string type. Test this using the DesiredType.
    If cevent.DesiredType IsNot GetType(String) Then
        Exit Sub
    End If
    
    ' Use the ToString method to format the value as currency ("c").
    cevent.Value = CType(cevent.Value, decimal).ToString("c")
End Sub

Private Sub CurrencyStringToDecimal(sender As Object, cevent As ConvertEventArgs)
    ' The method converts back to decimal type only.
    If cevent.DesiredType IsNot GetType(Decimal) Then
        Exit Sub
    End If

    ' Convert the string back to decimal using the shared Parse method.
   cevent.Value = Decimal.Parse(cevent.Value.ToString, _
  NumberStyles.Currency, nothing)

End Sub

Private Sub BindControl
    ' Create the binding first. The OrderAmount is typed as Decimal.
    Dim b As Binding = New Binding _
        ("Text", ds, "Customers.custToOrders.OrderAmount")
    ' Add the delegates to the event.
    AddHandler b.Format, AddressOf DecimalToCurrencyString
    AddHandler b.Parse, AddressOf CurrencyStringToDecimal
    text1.DataBindings.Add(b)
End Sub

Keterangan

Peristiwa Format dan Parse memungkinkan Anda membuat format kustom untuk menampilkan data. Misalnya, jika data dalam tabel berjenis Decimal, Anda dapat menampilkan data dalam format mata uang lokal dengan mengatur Value properti ke ConvertEventArgs nilai yang diformat dalam peristiwa tersebut Format . Anda akibatnya harus membatalkan format nilai yang ditampilkan dalam peristiwa tersebut Parse .

Peristiwa Parse terjadi dalam kondisi berikut:

• Setelah peristiwa Validated terjadi Control .

• EndCurrentEdit Ketika metode dipanggilBindingManagerBase.

• Current Saat dari BindingManagerBase perubahan (dengan kata lain, saat Position perubahan).

Untuk informasi selengkapnya tentang menangani peristiwa, lihat Menangani dan Menaikkan Peristiwa.

Lihat juga

• Format
• OnParse(ConvertEventArgs)
• PositionChanged
• CurrentChanged