CancelEventArgs.Cancel Properti

Definisi

Ruang nama:

System.ComponentModel

Rakitan:

System.ComponentModel.dll

Sumber:

CancelEventArgs.cs

Mendapatkan atau menetapkan nilai yang menunjukkan apakah acara harus dibatalkan.

public:
 property bool Cancel { bool get(); void set(bool value); };

public bool Cancel { get; set; }

member this.Cancel : bool with get, set

Public Property Cancel As Boolean

Nilai Properti

Boolean

true jika acara harus dibatalkan; jika tidak, false.

Contoh

Contoh berikut menggunakan CancelEventArgs dan CancelEventHandler untuk menangani FormClosing peristiwa Form. Kode ini mengasumsikan bahwa Anda telah membuat Form dengan variabel tingkat Boolean kelas bernama isDataSaved. Ini juga mengasumsikan bahwa Anda telah menambahkan pernyataan untuk memanggil OtherInitialize metode dari metode formulir Load atau konstruktor (setelah panggilan ke InitializeComponent).

private:
   // Call this method from the InitializeComponent() method of your form
   void OtherInitialize()
   {
      this->Closing += gcnew CancelEventHandler( this, &Form1::Form1_Cancel );
      this->myDataIsSaved = true;
   }

   void Form1_Cancel( Object^ /*sender*/, CancelEventArgs^ e )
   {
      if ( !myDataIsSaved )
      {
         e->Cancel = true;
         MessageBox::Show( "You must save first." );
      }
      else
      {
         e->Cancel = false;
         MessageBox::Show( "Goodbye." );
      }
   }

// Call this method from the constructor of your form
    private void OtherInitialize() {
       this.Closing += new CancelEventHandler(this.Form1_Closing);
       // Exchange commented line and note the difference.
       this.isDataSaved = true;
       //this.isDataSaved = false;
    }

    private void Form1_Closing(Object sender, CancelEventArgs e) {
       if (!isDataSaved) {
          e.Cancel = true;
          MessageBox.Show("You must save first.");
       }
       else {
          e.Cancel = false;
          MessageBox.Show("Goodbye.");
       }
    }

' Call this method from the Load method of your form.
Private Sub OtherInitialize()
    ' Exchange commented line and note the difference.
    Me.isDataSaved = True
    'Me.isDataSaved = False
End Sub

Private Sub Form1_Closing(sender As Object, e As _
   System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
    If Not isDataSaved Then
        e.Cancel = True
        MessageBox.Show("You must save first.")
    Else
        e.Cancel = False
        MessageBox.Show("Goodbye.")
    End If
End Sub