- How can I remove the “—–Series1” text (top right, near button1)
- How can I make the blue stepline thinker, and remove the background lines?
- How can I draw color to the background, such as the area from y=0 to y=1 colored as grey.
- How can I add mousewheel event, so that i can use Ctrl+mousewheel to zoom in and out the chart?
Thank you!

Below I have provided some example code to answer your questions. My answers to 3 and 4 are basic examples, and you will have to calculate the correct values for painting and zooming in your application.