private void VertexMouseUp(object sender, MouseEventArgs e) { if (GraphMode == GraphMode.InsertingMode) { UIElement element = sender as UIElement; Line line = sender as Line; addedEdge.Visibility = Visibility.Hidden; if (line == null) { Vertex currentVertex = VertexDict[element]; if (currentVertex != clickedVertex) { clickedEdge = Core.CreateEdge(currentVertex, clickedVertex); } } } }