在switch语句中使用(动画)块时崩溃

Question

这段代码可以工作(带动画的if语句)：

// works
if (_camOrientation == UIDeviceOrientationPortrait) {
    [UIView animateWithDuration:0.5f animations:^(void){
        [_distanceView setTransform:CGAffineTransformMakeRotation(degreesToRadian(0.0))];
    }];
} else if (_camOrientation == UIDeviceOrientationLandscapeLeft) {
    [UIView animateWithDuration:0.5f animations:^(void){
        [_distanceView setTransform:CGAffineTransformMakeRotation(degreesToRadian(90.0))];
    }];
}

这也是有效的(switch-statement没有动画)：

// works
switch (_camOrientation) {
    case UIDeviceOrientationPortrait:
        [_distanceView setTransform:CGAffineTransformMakeRotation(degreesToRadian(0.0))];
        break;

    case UIDeviceOrientationLandscapeLeft:
        [_distanceView setTransform:CGAffineTransformMakeRotation(degreesToRadian(90.0))];
        break;

    default:
        break;
}

这个程序崩溃了(带有动画的switch-statement)：

// crashes
switch (_camOrientation) {
    case UIDeviceOrientationPortrait:
        [UIView animateWithDuration:0.5f animations:^(void){
            [_distanceView setTransform:CGAffineTransformMakeRotation(degreesToRadian(0.0))];
        }];
        break;

    case UIDeviceOrientationLandscapeLeft:
        [UIView animateWithDuration:0.5f animations:^(void){
            [_distanceView setTransform:CGAffineTransformMakeRotation(degreesToRadian(90.0))];
        }];
        break;

    default:
        break;
}

为什么我不能在switch语句中使用动画块？！？

Answer 1

您应该能够:)

尝试在案例中添加{ }，如下所示：

case UIDeviceOrientationPortrait: {
    [UIView animateWithDuration:0.5f animations:^void{
        [_distanceView setTransform:CGAffineTransformMakeRotation(0.0)];
    }];
    break;
}