ios - UIView 动画在 for 循环中的运行顺序不正确 - iOS

Question

我有一个简单的 for 循环，可以为一些 UILabel 设置动画。我的 for 循环中有动画 block 代码的原因是因为显然我有多个标签要制作动画。

现在，每次整个 for 循环完成后，我的程序都会将 UILabel 中的数字递增 1。然而，当动画发生时，数字已经递增(这不是我想要的)，即使数字递增代码出现在 for 循环之后......

我不确定我是否已经正确解释了问题，但考虑到我的问题，因为我们知道动画在主线程上运行的事实，我们如何确保动画以正确的顺序发生(在 for 循环中)???

这是我的代码:

for (int loop = 0; loop < [number_arrange count]; loop++) {

            if ([number_arrange[loop] integerValue] == checknum) {
                [anim_check replaceObjectAtIndex:loop withObject:[NSNumber numberWithInteger:1]];

                [UIView animateWithDuration:0.4 delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{

                    ((UILabel*)_labels_anim[loop]).transform = CGAffineTransformMakeScale(5.0, 5.0);
                    ((UILabel*)_labels_anim[loop]).layer.anchorPoint = CGPointMake(0.5, 0.5);
                    ((UILabel*)_labels_anim[loop]).frame = CGRectOffset(((UILabel*)_labels_anim[loop]).frame, 0.0, -20.0);
                    ((UILabel*)_labels_anim[loop]).alpha = 0.0;

                } completion:^(BOOL finished) {

                    ((UILabel*)_labels_anim[loop]).transform = CGAffineTransformMakeScale(1.0, 1.0);
                    ((UILabel*)_labels_anim[loop]).layer.anchorPoint = CGPointMake(0.5, 0.5);
                    ((UILabel*)_labels_anim[loop]).frame = CGRectOffset(((UILabel*)_labels_anim[loop]).frame, 0.0, 20.0);
                    ((UILabel*)_labels_anim[loop]).alpha = 1.0;
                }];
            }
        }

谢谢你抽出时间，丹。

Answer 1

问题是您正在从两个 block 内部访问“循环”。为什么不尝试在动画 block 中运行循环？像这样:

[UIView animateWithDuration:0.4 delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{
    for (int loop = 0; loop < [number_arrange count]; loop++) {
        if ([number_arrange[loop] integerValue] == checknum) {
            [anim_check replaceObjectAtIndex:loop withObject:[NSNumber numberWithInteger:1]];

            ((UILabel*)_labels_anim[loop]).transform = CGAffineTransformMakeScale(5.0, 5.0);
            ((UILabel*)_labels_anim[loop]).layer.anchorPoint = CGPointMake(0.5, 0.5);
            ((UILabel*)_labels_anim[loop]).frame = CGRectOffset(((UILabel*)_labels_anim[loop]).frame, 0.0, -20.0);
            ((UILabel*)_labels_anim[loop]).alpha = 0.0;
        }
    }
} completion:^(BOOL finished) {
    for (int loop = 0; loop < [number_arrange count]; loop++) {
        if ([number_arrange[loop] integerValue] == checknum) {
            ((UILabel*)_labels_anim[loop]).transform = CGAffineTransformMakeScale(1.0, 1.0);
            ((UILabel*)_labels_anim[loop]).layer.anchorPoint = CGPointMake(0.5, 0.5);
            ((UILabel*)_labels_anim[loop]).frame = CGRectOffset(((UILabel*)_labels_anim[loop]).frame, 0.0, 20.0);
            ((UILabel*)_labels_anim[loop]).alpha = 1.0;
        }
    }
}];

希望对您有所帮助!