Question

我有一个UIView，屏幕底部放置了UITextField，当键盘出现时我想向上移动。我添加了keyboardFrameDidChange观察员，以便在键盘出现/消失时收到通知。这是方法：

-(void)keyboardFrameDidChange:(NSNotification*)notification{

NSDictionary* info = [notification userInfo];

CGRect kKeyBoardFrame = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];

[bottomView layoutIfNeeded];

[UIView animateWithDuration:[notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue] delay:0 options:[[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue] animations:^{

    [bottomView setFrame:CGRectMake(0, kKeyBoardFrame.origin.y - bottomView.frame.size.height, 320, bottomView.frame.size.height)];

} completion:^(BOOL finished) {

    [bottomView layoutIfNeeded];

    NSLog(@"frame ** %f",self.bottomView.frame.origin.y);
}];
}

此处frame of bottomView正在发生变化，但UI中没有任何变化。 bottomView只是保持在最底层。可能是什么原因？

Answer 1

这听起来像是一个自动布局问题。如果启用了自动布局，则应通过调整其约束而不是设置框架来更改视图的位置。将IBOutlet设置为文本字段和superview底部之间的约束（在我的示例中为bottomCon），然后进行调整。

-(void)keyboardFrameDidChange:(NSNotification*)notification{

    NSDictionary* info = [notification userInfo];

    CGRect kKeyBoardFrame = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];

    [_bottomView layoutIfNeeded];

    [UIView animateWithDuration:[notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue] delay:0 options:[[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue] animations:^{

        self.bottomCon.constant = kKeyBoardFrame.origin.y;
        [_bottomView layoutIfNeeded];
    } completion:^(BOOL finished) {
        NSLog(@"frame ** %f",self.bottomView.frame.origin.y);
    }];
}

iOS 8 UIView没有得到更新问题

1 个答案: