// the MouseDown event for the left TextBox. This event fires when the
// mouse is in the control's bounds and the mouse button is clicked.
private void TextBoxLeft_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
txtLeft.SelectAll();
//invoke the drag and drop operation
txtLeft.DoDragDrop(txtLeft.SelectedText, DragDropEffects.Move | DragDropEffects.Copy);
}
}
/// <summary>
/// The MouseDown event of the source control is used to initiate a drag operation.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">A MouseEventArgs that contains the event data.</param>
private void textBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Sets a reference to the control that initiated the DragDrop operation, so
// that the target control can implement logic to handle data dragged from
// specific controls differently. This control reference is also used in the
// case of a Move effect to remove the data from the source control after a drop.
sourceControl = textBox1;
// Record the mouse button that initiated this operation in order to allow
// target controls to respond differently to drags with the right or left
// mouse buttons.
mouseButton = e.Button;
// This initiates a DragDrop operation, specifying that the data to be dragged
// with be the text stored in the textBox1 control. This also specifies
// that both Copy and Move effects will be allowed.
textBox1.DoDragDrop(textBox1.Text, DragDropEffects.Move | DragDropEffects.Copy);
}