When I am tring to create a screenshot for my app I cannot get the method.
My app is a software that draw pictures with svg and html5 canvas, and I want to get a screenshot of the image when someone drawing a paintings.
You might be better off getting everything into canvas and getting a url from the canvas:
http://stackoverflow.com/questions/3975499/convert-svg-to-image-jpeg-png-etc-in-the-browser