ScrollView的scrollRectTo在键盘通知上可见 在iOS 11中无法正常工作

Question

我有一个滚动视图，其中包含许多文本字段作为子视图，我希望选定的文本字段（_activeField）在键盘出现时向上滚动。

- (void) keyboardUP:(NSNotification *)notification
{
NSDictionary* info = [notification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height + 10, 0.0);
_scroller.contentInset = contentInsets;
_scroller.scrollIndicatorInsets = contentInsets;
CGRect aRect = App_Delegate.window.frame;
aRect.size.height -= kbSize.height;
CGRect rect = [_activeField convertRect:_activeField.frame fromView:App_Delegate.window];
if (!CGRectContainsPoint(aRect, rect.origin) )
{
    [_scroller scrollRectToVisible:rect animated:YES];
}

}

此代码适用于iOS 10，但是在iOS 11中，它不起作用，"scrollRectToVisible"即使其内容大小正确也不会滚动ScrollView。

Answer 1

我不确定

- (void) keyboardUP:(NSNotification *)notification

但已经看到了类似的问题

- (void)handleKeyobardDidShowNotification:(NSNotification *)notification 

看起来这不再在 iOS 11 的主线程上运行。

尝试在主线程上运行你调用的scrollRectToVisible，如下所示

dispatch_async(dispatch_get_main_queue(), ^{
        [_scroller scrollRectToVisible:targetPosition animated:YES];
    });

Answer 2

这是此问题的副本。

使用UIKeyboardFrameEndUserInfoKey

if let userInfo = notification.userInfo {
    if let keyboardSize = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        print(keyboardSize)
    }
}

和 ObjC

- (void)keyboardWillShow:(NSNotification *)notification {
    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
}