Question

根据我在回复this question时所读到的内容，以下内容应该有效：

UIImageView *snapshotView = [[UIImageView alloc]initWithFrame:self.window.frame];

[self.container.view addSubview:snapshotView];


for(int i = 1;i < 5; i = i +1){

        UIImage *snapshotImage = [self blurredInboxBgImageWithRadius: (i * 5)];
        [UIView transitionWithView:snapshotView
                      duration:2.0f
                       options:UIViewAnimationOptionCurveLinear
                    animations:^{
                        snapshotView.image = snapshotImage;
                    } completion:nil];
    }

但它没有。它根本不会为图像更改设置动画。我错过了什么？

Answer 1

两件事：

您需要在上一次转换的完成块中启动下一次转换，以使它们按顺序发生。
您需要使用UIViewAnimationOptionTransitionCrossDissolve选项，而不是UIViewAnimationOptionCurveLinear

这里有一些代码我模拟了标签上的一系列转换：

@interface ViewController ()
@property (nonatomic) NSInteger iterationCount;
@property (strong, nonatomic) IBOutlet UILabel *label;
@end

@implementation ViewController

// called on button tap
- (IBAction)startTransitioning:(id)sender {
    self.iterationCount = 0;
    [self iterateTransition];
}

- (void)iterateTransition
{
    if (self.iterationCount < 5) {
        self.iterationCount++;
        [UIView transitionWithView:self.label duration:2 options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
            self.label.text = [NSString stringWithFormat:@"%d", self.iterationCount];
        } completion:^(BOOL finished) {
            [self iterateTransition];
        }];
    } else {
        self.iterationCount = 0;
    }
}

@end

transitionWithView无法从UIImageView交换UIImage

1 个答案: