问题
I rotate/scale a UIVIew using [UIView transform:] and this works well. However, as soon as I change the view's frame origin the contents of the view begins to scale 'weirdly' even though I am not performing any further CGAffineTransforms.
Why does this occur? How can I prevent it?
Update 1:
The docs suggest that the frame is invalid after a transform. Can I move the view via it's 'center' property instead?
Update 2:
Setting the views center did allow me to translate the view successfully after a transform had been applied.
回答1:
Can I move the view via it's 'center' property instead?
The documentation defines the center property as:
The center of the frame.
and says:
The center is specified within the coordinate system of its superview.
I'd try it.
回答2:
From the UIView docs:
transform:
Warning: If this property is not the identity transform, the value of the frame property is undefined and therefore should be ignored.
The center property is just a convenience method that really resets the frame's origin.
Edit: appended to answer comment:
If you're using the transform property and want to reposition your view, you have to concatenate the translation to your transform using:
view.transform = CGAffineTransformTranslate(view.transform, tx, tx);
来源：https://stackoverflow.com/questions/1047947/resetting-the-origin-of-a-transformed-uiview-descends-into-craziness