Rotate UIView iPhone | 易学教程

问题

I am working on a puzzle game and I need to rotate the puzzle pieces to 90 degrees angle on every double tap.

I have tried to do did using two different ways. First method is this one:

[UIView beginAnimations:@"rotate" context:nil];
[UIView setAnimationDuration:0.5];
self.transform = CGAffineTransformMakeRotation(90);
[UIView commitAnimations];

The only problems with that are that the piece is NOT rotating 90 degrees; it is rotating by around 100 degrees, and that this animation is modifying the frame of the puzzle piece UIView.

This is my console output:

frame BEFORE ROTATION: {{35, 178}, {80, 80}}

frame AFTER ROTATION: {{21.3172, 164.317}, {107.366, 107.366}}

The second method I tried was this one:

CABasicAnimation* spinAnimation = [CABasicAnimation
                                       animationWithKeyPath:@"transform.rotation"];
spinAnimation.toValue = [NSNumber numberWithFloat:1];
[self.layer addAnimation:spinAnimation forKey:@"spinAnimation"];

The problem with this method is that after finishing the rotation, it is reversing my UIView to its previous state.

How can I rotate the puzzle piece with an animation without having these problems?

回答1:

Try

[UIView beginAnimations:@"rotate" context:nil];
[UIView setAnimationDuration:0.5];
self.transform = CGAffineTransformMakeRotation(DegreesToRadians(90));
[UIView commitAnimations];

where you can define DegreesToRadians as

#define DegreesToRadians(x) ((x) * M_PI / 180.0)

回答2:

Your first method is good, exept the angle is in radian

[UIView beginAnimations:@"rotate" context:nil];
[UIView setAnimationDuration:0.5];
self.transform = CGAffineTransformMakeRotation(90/180*M_PI);
[UIView commitAnimations];

回答3:

Most everyone is now using animation blocks for iOS animating. So a little something like this is what I would recommend (of course you can set your own timing and animation options and degrees to rotate). Enjoy

[UIView animateWithDuration:0.4f delay:0.0f options:UIViewAnimationOptionCurveEaseOut animations:^{
        YOURVIEW.transform = CGAffineTransformMakeRotation(DegreesToRadians(180));
    } completion:^(BOOL finished) {

    }];

#define DegreesToRadians(x) ((x) * M_PI / 180.0)

if you are looking for a 360 degree turn that is a bit more tricky since it doesn't want to animate a rotation of what will end up being exactly where it started so use something like this:

- (void)rotateSpinningView:(UIView *)viewToSpin{
    [UIView animateWithDuration:1.5 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
        [viewToSpin setTransform:CGAffineTransformRotate(viewToSpin.transform, M_PI_2)];
    } completion:^(BOOL finished) {
        if (finished && !CGAffineTransformEqualToTransform(viewToSpin.transform, CGAffineTransformIdentity)) {
            [self rotateSpinningView:viewToSpin];
        }
    }];
}

回答4:

I this the best way is to declare C function

static inline CGFloat degreesToRadians(CGFloat degrees) {return (degrees) * M_PI / 180.0f;}

and the use it like this

[UIView beginAnimations:@"rotate" context:nil];
[UIView setAnimationDuration:0.5];
self.transform = CGAffineTransformMakeRotation(degreesToRadians(180.0f));
[UIView commitAnimations];

来源：https://stackoverflow.com/questions/5457122/rotate-uiview-iphone

标签

iphone

animation

uiview

rotation