private void richEditControl1_PreviewDragOver(object sender, DragEventArgs e)
{
Point windowsPoint = e.GetPosition((UIElement)richEditControl1);
DocumentPosition pos = RichEditHelper.GetDocumentPositionFromWindowsPoint(richEditControl1, windowsPoint);
if (pos == null)
{
return;
}
DrawRectange(pos);
richEditControl1.Document.CaretPosition = pos;
richEditControl1.ScrollToCaret();
}
public void DrawRectange(DocumentPosition pos)
{
if (canvas.Children.Contains(rectangle))
{
canvas.Children.Remove(rectangle);
}
System.Drawing.RectangleF drawingRectange = RichEditHelper.GetRectangleFromDocumentPosition(richEditControl1, pos);
rectangle = new Rectangle()
{
Stroke = Brushes.Blue,
StrokeThickness = 1,
Width = 2,
Height = drawingRectange.Height
};
canvas.Children.Add(rectangle);
Canvas.SetLeft(rectangle, drawingRectange.X);
Canvas.SetTop(rectangle, drawingRectange.Y);
}
