|UIImage *||NIStretchableImageFromImage (UIImage *image)|
For manipulating UIImage objects.
Returns an image that is stretchable from the center.
A common use of this method is to create an image that has rounded corners for a button and then assign a stretchable version of that image to a UIButton.
This stretches the middle vertical and horizontal line of pixels, so use care when stretching images that have gradients. For example, an image with a vertical gradient can be stretched horizontally, but will look odd if stretched vertically.