Control.DragDrop Event (System.Windows.Forms)

DragDrop Event

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This page is specific to

Microsoft Visual Studio 2010/.NET Framework 4

Other versions are also available for the following:

.NET Framework Class Library

Control..::.DragDrop Event

Occurs when a drag-and-drop operation is completed.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)

Syntax

Visual Basic

Public Event DragDrop As DragEventHandler

public event DragEventHandler DragDrop

Visual C++

public:
 event DragEventHandler^ DragDrop {
    void add (DragEventHandler^ value);
    void remove (DragEventHandler^ value);
}

member DragDrop : IEvent<DragEventHandler,
    DragEventArgs>

Remarks

The X and Y properties of the DragEventArgs are in screen coordinates, not client coordinates. The following line of Visual C# code converts the properties to a client Point.

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

Note
In versions earlier than .NET Framework version 2.0, if you put a UserControl with DragEnter and DragDrop events on a Windows Form and drag and drop something onto the UserControl at design time, the DropDrop and DropEnter events are raised. However, when you close and reopen the solution, the DragEnter and DragDrop events are not raised again.

For more information about handling events, see Consuming Events.

Examples

This code excerpt demonstrates using the DragDrop event. See the DoDragDrop method for the complete code example.

Visual Basic

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

private 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(typeof(System.String))) {

        Object item = (object)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";
}

Visual C++

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";
}

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Control Class

System.Windows.Forms Namespace