WPF C# Drag and Drop

c#, drag-and-drop, label, textbox, wpf

Solution

It worked for me.

private void lbl_MouseDown(object sender, MouseButtonEventArgs e)
{
    Label _lbl = sender as Label;
    DragDrop.DoDragDrop(_lbl, _lbl.Content, DragDropEffects.Move);
}

You do not need `MouseMove` and `DragEnter` events for `Label` if you are using them just for Drag purpose.

Replace `Drop` event with `PreviewDrop` for `TextBox` as shown below:

tbox.Drop += new DragEventHandler(tbox_Drop);

with this

tbox.PreviewDrop += new DragEventHandler(tbox_PreviewDrop);

private void tbox_PreviewDrop(object sender, DragEventArgs e)
{
    (sender as TextBox).Text = string.Empty;
}

Problem

Basically i am doing a drag and drop using textbox and labels , by dragging a label to a textbox . Textboxes and Labels are created in same for loop . I have dynamically created textboxes ( textbox is the drop target) like this : ``` TextBox tbox = new TextBox(); tbox.Width = 250; tbox.Height = 50; tbox.AllowDrop = true; tbox.FontSize = 24; tbox.BorderThickness = new Thickness(2); tbox.BorderBrush = Brushes.BlanchedAlmond; tbox.Drop += new DragEventHandler(tbox_Drop); if (lstQuestion[i].Answer.Trim().Length > 0) { wrapPanel2.Children.Add(tbox); answers.Add(lbl.Content.ToString()); MatchWords.Add(question.Content.ToString(), lbl.Content.ToString()); } ``` I have also dynanmically create labels ( label is the drag target) like this : ``` Dictionary<string, string> shuffled = Shuffle(MatchWords); foreach (KeyValuePair<string, string> s in shuffled) { Label lbl = new Label(); lbl.Content = s.Value; lbl.Width = 100; lbl.Height = 50; lbl.FontSize = 24; lbl.DragEnter += new DragEventHandler(lbl_DragEnter); lbl.MouseMove += new MouseEventHandler(lbl_MouseMove); lbl.MouseDown +=new MouseButtonEventHandler(lbl_MouseDown); // lbl.MouseUp +=new MouseButtonEventHandler(lbl_MouseUp); dockPanel1.Children.Add(lbl); } ``` I have 2 issues here . 1st . I am using tbox.drop event to display MessageBox.Show( something ) ; to display a messagebox when the drag target is being drop but it doesn't work . here is my code : ``` private void tbox_Drop(object sender, DragEventArgs e) { MessageBox.Show("Are you sure?"); } ``` Second , i also want to clear the tbox.Text when the drag target is dropped because i might have other drag target dropped into the tbox previously. So i want to clear the tbox.Text and drop the drag target everytime when i drag the target to textbox . How do i do that? i am stucked at which event i should use for this and how do i access tbox from those event handlers ?

Original source