how to draw an UIImageView into -drawRect of another view?

Question

I have several UIImageView objects which have been rotated and scaled. Because they are just background images, and represent an non-highlighted-state, I want to draw them to the canvas of the view so that I can get rid of them in memory. The view has a big bitmap anyways, so it would save a lot of memory to put them in there rather than adding as subview.

It seems I can only call something like -drawInRect for an UIImage, but how about an UIImageView with transforms on it? Oh yes, and it's positioned with frame origin.

I just want to draw it to another UIView's bitmap the same way as it appears when adding as subview.

Answer 1

Using drawInRect: with a rect of different origin and size of the image, you can effectively make any scaling and translation you want. You can also handle rotations with the [CGContextRotateCTM][1] function (CTM = current transformation matrix). There are other CGContext..CTM functions as well, so you have multiple approaches.