Control.DragDrop Kejadian

Definisi

Ruang nama:

System.Windows.Forms

Rakitan:

System.Windows.Forms.dll

Sumber:

Control.cs

Terjadi ketika operasi seret dan letakkan selesai.

public:
 event System::Windows::Forms::DragEventHandler ^ DragDrop;

public event System.Windows.Forms.DragEventHandler? DragDrop;

member this.DragDrop : System.Windows.Forms.DragEventHandler 

Public Custom Event DragDrop As DragEventHandler 

Jenis Acara

DragEventHandler

Contoh

Kutipan kode ini menunjukkan penggunaan DragDrop peristiwa. DoDragDrop Lihat metode untuk contoh kode lengkap.

void ListDragTarget_DragDrop( Object^ /*sender*/, System::Windows::Forms::DragEventArgs^ e )
{
   // Ensure that the list item index is contained in the data.
   if ( e->Data->GetDataPresent( System::String::typeid ) )
   {
      Object^ item = dynamic_cast<Object^>(e->Data->GetData( System::String::typeid ));
      
      // Perform drag-and-drop, depending upon the effect.
      if ( e->Effect == DragDropEffects::Copy || e->Effect == DragDropEffects::Move )
      {
         // Insert the item.
         if ( indexOfItemUnderMouseToDrop != ListBox::NoMatches )
                        ListDragTarget->Items->Insert( indexOfItemUnderMouseToDrop, item );
         else
                        ListDragTarget->Items->Add( item );
      }
   }

   // Reset the label text.
   DropLocationLabel->Text = "None";
}

private void ListDragTarget_DragDrop(object sender, DragEventArgs e)
{
    // Ensure that the list item index is contained in the data.
    if (e.Data.GetDataPresent(typeof(System.String)))
    {
        Object item = e.Data.GetData(typeof(System.String));

        // Perform drag-and-drop, depending upon the effect.
        if (e.Effect == DragDropEffects.Copy ||
            e.Effect == DragDropEffects.Move)
        {
            // Insert the item.
            if (indexOfItemUnderMouseToDrop != ListBox.NoMatches)
                ListDragTarget.Items.Insert(indexOfItemUnderMouseToDrop, item);
            else
                ListDragTarget.Items.Add(item);
        }
    }
    // Reset the label text.
    DropLocationLabel.Text = "None";
}

Private Sub ListDragTarget_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles ListDragTarget.DragDrop
    ' Ensures that the list item index is contained in the data.

    If (e.Data.GetDataPresent(GetType(System.String))) Then

        Dim item As Object = CType(e.Data.GetData(GetType(System.String)), System.Object)

        ' Perform drag-and-drop, depending upon the effect.
        If (e.Effect = DragDropEffects.Copy Or
            e.Effect = DragDropEffects.Move) Then

            ' Insert the item.
            If (indexOfItemUnderMouseToDrop <> ListBox.NoMatches) Then
                ListDragTarget.Items.Insert(indexOfItemUnderMouseToDrop, item)
            Else
                ListDragTarget.Items.Add(item)

            End If
        End If
        ' Reset the label text.
        DropLocationLabel.Text = "None"
    End If
End Sub

Keterangan

Properti XY dan DragEventArgs berada dalam koordinat layar, bukan koordinat klien. Baris kode berikut mengonversi properti menjadi klien Point.

Point clientPoint = targetControl.PointToClient(new Point(de.X, de.Y));

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

Lihat juga

• DragEnter
• DragLeave
• DragOver
• DoDragDrop(Object, DragDropEffects)
• OnDragDrop(DragEventArgs)