Question

我有动画代码可以移动按钮和其他一些视图以响应键盘显示：

NSValue *frameValue = [note userInfo][UIKeyboardFrameEndUserInfoKey];
CGRect keyboardFrame = [frameValue CGRectValue];
CGFloat keyboardHeight = keyboardFrame.size.height*kCGPKeyboardAnimationTranslationAdjustmentFactor;
CGFloat animationDuration = [[note userInfo][UIKeyboardAnimationDurationUserInfoKey] doubleValue];
UIViewAnimationOptions animationCurveOption = [[note userInfo][UIKeyboardAnimationCurveUserInfoKey] integerValue] >> 16;

CGPoint submitButtonCenter = [[self submitButton] center];
CGPoint offsetSubmitButtonCenter = CGPointMake(submitButtonCenter.x, submitButtonCenter.y-keyboardHeight);

__block __weak __typeof(self) wSelf = self;
NSCParameterAssert([wSelf isKindOfClass:[self class]]);
[UIView animateWithDuration:animationDuration delay:0.0f options:animationCurveOption animations:^{

    [[wSelf submitButton] setCenter:offsetSubmitButtonCenter];

} completion:nil
    }];

但是，当我显示UIAlertView

时，此动画稍后会撤消

- (void)displayError:(NSError*)error {
    NSCParameterAssert([NSThread isMainThread]);
    NSString *errorDescription = [error description];
    UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"" message:errorDescription delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    NSLog(@"%s: Recursive View Description: %@",__PRETTY_FUNCTION__,[[[self view] subviews] description]);
    [av show];
    NSLog(@"Is it still there? %s Recursive View Description: %@",__PRETTY_FUNCTION__,[[[self view] subviews] description]);
}

调用[av show]后，按钮框架会立即更改，将其恢复到动画之前的确切位置。评论[av show]会使错误消失，因此看起来像副作用。

虽然那个代码不存在，但还有其他几个UIView和UITextField对象以相同的方式移动。它们不受影响，只有UIButton移动。

任何人都有关于如何修复它的想法？

Answer 1

经过几个小时的调试并找出根本原因后，结果很简单。

解除UIAlertView触发的自动布局，这是将提交按钮移回原处的位置。设置约束或关闭自动布局并使用自动调整遮罩修复了问题。

UIAlertView和基于块的动画

1 个答案: