I am animating some interface elements by using a CGAffineTransform. It works fine, but for some reason a toolbar animates with this method does not animate smoothly. It sort of pops or flashes (seems to move up before moving down) before animating to the desired position. The solution could be to use a different type of view, but i am still curious as to what causes this.
CGAffineTransform toolbarViewTransform = CGAffineTransformMake(1, 0, 0, 1, 0, 0);
[UIView animateWithDuration:0.2
animations:^{toolBar.transform = toolbarViewTransform;}
completion:^(BOOL finished){ }];
I had this exact same problem.
In the end I found that AutoLayout was causing this. Although I didn't actually find out how or why.
In the end I fixed it by just disabling auto layout.
If this is an option for you then I'd suggest doing that.