Public Class Form4
    Inherits System.Windows.Forms.Form
#Region " Vom Windows Form Designer generierter Code "
#End Region
    Private MouseDownTime As Date = Now
    Private Sub TextBox_MouseMove(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseMove, _
      TextBox2.MouseMove
        If e.Button = MouseButtons.Left And _
             (Now > Me.MouseDownTime.AddMilliseconds(500)) And _
             CType(sender, TextBox).SelectionLength Then
             sender.DoDragDrop(sender.Text, DragDropEffects.Copy)
        End If
    End Sub
    Private Sub TextBox_MouseDown(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.MouseEventArgs) Handles TextBox1.MouseDown, _
      TextBox2.MouseDown
        If e.Button = MouseButtons.Left Then Me.MouseDownTime = Now()
    End Sub
    Private Sub TextBox_DragEnter(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.DragEventArgs) Handles TextBox1.DragEnter, _
      TextBox2.DragEnter
        e.Effect = DragDropEffects.Copy
    End Sub
    Private Sub TextBox_DragDrop(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.DragEventArgs) Handles TextBox1.DragDrop, _
      TextBox2.DragDrop
        CType(sender, TextBox).Text &= e.Data.GetData("System.String", True)
    End Sub
End Class