public Window1(){    InitializeComponent();    // "tb" is a TextBox    DataObject.AddPastingHandler(tb, new DataObjectPastingEventHandler(OnPaste));}private void OnPaste(object sender, DataObjectPastingEventArgs e){    var isText = e.SourceDataObject.GetDataPresent(System.Windows.DataFormats.Text, true);    if (!isText) return;    var text = e.SourceDataObject.GetData(DataFormats.Text) as string;    }