防止背景图像拉伸视图

Whenever I assign background to a view that is laid out with wrap_content, if the background image is larger than a view, the view is stretched so that it can hold the entire background. Why is it so and how to prevent it? It occurs even if the image is 9-patch and has stretchable areas marked - why isn't the image shrunk to the size of the view?Whenever I assign background to a view that is