ios - iOS 8 键盘隐藏了我的文本视图

Question

我有一个UIViewController使用self.accountViewController.modalPresentationStyle = UIModalPresentationFormSheet;，现在在 iOS 8 中，UITextView当它向上推时，最后一个从键盘隐藏。如何避免它？

Answer 1

@Oleg 的解决方案很好，但它没有考虑键盘尺寸的变化，而它已经显示了......此外，他对动画持续时间和一些其他参数进行了硬编码。请参阅下面的解决方案：

添加一个观察者UIKeyboardWillChangeFrameNotification到viewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardFrameWillChange:) name:UIKeyboardWillChangeFrameNotification object:nil];

然后添加方法：

- (void)keyboardFrameWillChange:(NSNotification *)notification
{
    CGRect keyboardEndFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGRect keyboardBeginFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue];
    UIViewAnimationCurve animationCurve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
    NSTimeInterval animationDuration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] integerValue];

    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:animationDuration];
    [UIView setAnimationCurve:animationCurve];

    CGRect newFrame = self.view.frame;
    CGRect keyboardFrameEnd = [self.view convertRect:keyboardEndFrame toView:nil];
    CGRect keyboardFrameBegin = [self.view convertRect:keyboardBeginFrame toView:nil];

    newFrame.origin.y -= (keyboardFrameBegin.origin.y - keyboardFrameEnd.origin.y);
    self.view.frame = newFrame;

    [UIView commitAnimations];
}

不要忘记在 viewDidUnload 和 Dealloc 中删除键盘观察者。

Answer 2

@newton_guima 上面的答案的Swift 版本，以防有人想要它。

将观察者添加UIKeyboardWillChangeFrameNotification到viewDidLoad()：

NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardFrameWillChange:", name: UIKeyboardWillChangeFrameNotification, object: nil)

然后添加这个方法：

func keyboardFrameWillChange(notification: NSNotification) {
    let keyboardBeginFrame = (notification.userInfo! as NSDictionary).objectForKey(UIKeyboardFrameBeginUserInfoKey)!.CGRectValue
    let keyboardEndFrame = (notification.userInfo! as NSDictionary).objectForKey(UIKeyboardFrameEndUserInfoKey)!.CGRectValue

    let animationCurve = UIViewAnimationCurve(rawValue: (notification.userInfo! as NSDictionary).objectForKey(UIKeyboardAnimationCurveUserInfoKey)!.integerValue)

    let animationDuration: NSTimeInterval = (notification.userInfo! as NSDictionary).objectForKey(UIKeyboardAnimationDurationUserInfoKey)!.doubleValue

    UIView.beginAnimations(nil, context: nil)
    UIView.setAnimationDuration(animationDuration)
    UIView.setAnimationCurve(animationCurve!)

    var newFrame = self.view.frame
    let keyboardFrameEnd = self.view.convertRect(keyboardEndFrame, toView: nil)
    let keyboardFrameBegin = self.view.convertRect(keyboardBeginFrame, toView: nil)

    newFrame.origin.y -= (keyboardFrameBegin.origin.y - keyboardFrameEnd.origin.y)
    self.view.frame = newFrame;

    UIView.commitAnimations()
}

然后移除观察者，无论您从视图过渡到何处或在deinit：

NSNotificationCenter.defaultCenter().removeObserver(self)

Answer 3

为了解决你的问题，你应该改变frame或constrain.textview

给你的小提示：

使用通知来检测键盘何时显示或隐藏。

通知样本：

 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

而不是更改上面提到的参数之一。

改变框架的例子：

- (void)keyboardWillHide:(NSNotification *)notification
{
    [self.view layoutIfNeeded];
    [UIView animateWithDuration:0.2
                     animations:^{
    [self setStartingFrame:self.commentsView.frame.size.height - commentViewOutlet_.frame.size.height - tabBarOffset_];
                         [self.view layoutIfNeeded];
                     }];
}