I'm a beginner just like you. I struggled a lot with AddTransient. I spent a lot of time on it, trying to draw a line, but it wouldn't appear. In the end, I suspect the issue wasn't that the line wasn't being drawn, but that it wasn't visible. When I set the line.ColorIndex property, I was finally able to see it on the screen. I assume that the line wasn't visible by default because the ColorIndex value hadn't been set. I hope this helps you.