UIView块动画从左到右和从左到右移动视图

Question

I wan't to animate a view that's shaped as an arrow, and I want it to animate from left to right, left to right and so on..

This code below is not working, I'm guessing I need a path, but don't know how to do that in a UIView block animation.

   [UIView animateWithDuration:.5 delay:0 options:UIViewAnimationOptionRepeat animations:^{
    controller.view.frame = frame1;
    controller.view.frame = frame2;

} completion:^(BOOL finished) {

}];

Answer 1

You can use UIViewAnimationOptionAutoreverse option, try the code below:

UIView * testView = [[UIView alloc] initWithFrame:CGRectMake(20.0f, 100.0f, 300.0f, 200.0f)];
[testView setBackgroundColor:[UIColor blueColor]];
[self.view addSubview:testView];

[UIView animateWithDuration:0.3f
                      delay:0.0f
                    options:UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse
                 animations:^{
                     [testView setFrame:CGRectMake(0.0f, 100.0f, 300.0f, 200.0f)];
                 }
                 completion:nil];

[testView release];

It'll repeat move from right to left, left to right, ... smoothly.

Answer 2

Assuming that frame1 is the starting position and frame2 is the end position before repeat.

The problem is that the animation is calculated at the end of the runloop therefore the frame1 is ignored and the view is simply moved to frame2 . If you move the setting of frame1 outside of the block then it should work fine. If you want the animation to play back and forward you will need to make it autoreverse with UIViewAnimationOptionAutoreverse