ios - 奇怪的索引越界异常

Question

我正在尝试以动画方式删除 ScrollView 内的 View 。 ScrollView 的 subview 是从对象数组中填充的。每个对象都有一个代表它的 View 。有时我在删除时会遇到indexOutOfBounds异常。这是我的删除代码:

-(void)deleteView:(UIView *)viewToDelete{
    [self.myObjects removeObjectAtIndex:viewToDelete.tag];
    [UIView animateWithDuration:0.5 animations:^{
        viewToDelete.alpha = 0.0;
        for (NSInteger index = viewToDelete.tag+1; index<self.myViews.count; index++){
            UIView *view = [self.myViews objectAtIndex:index];
            view.center = CGPointMake(view.center.x,view.center.y-viewToDelete.frame.size.height);
        }
    }]; completion:^(BOOL finished) {
        [view removeFromSuperview];
    }];

    [self.myViews removeObjectAtIndex:viewToDelete.tag];
    for (NSInteger index=0; index<self.myVies.count; index++){
        UIView *view = [self.myViews objectAtIndex:index];
        view.tag = index;
    }

}

Answer 1

问题出在动画 block

您应该知道动画 block 是异步处理的，因此您最后的代码可能会在动画过程中被调用，并在动画 block 内的迭代循环中造成困惑。你应该搬家

[self.myViews removeObjectAtIndex:viewToDelete.tag];
for (NSInteger index=0; index<self.myVies.count; index++){
    UIView *view = [self.myViews objectAtIndex:index];
    view.tag = index;
}

到完成 block