键盘出现时调整UITextView的大小

Question

我想在键盘出现时调整文本视图的大小.我的代码如下.我有自动布局,因此使用了来自superview的textView-> bottom space的约束,并通过IBOutlet distanceFromBottom引用它.

- (void)keyboardWillShow:(NSNotification *)notification
{
  [UIView animateWithDuration:0.3 animations:^{
    NSDictionary* d = [notification userInfo];
    CGRect r = [d[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    r = [textView convertRect:r fromView:Nil];
    if(IS_IPHONE_6||IS_IPHONE_6P)
      distanceFromBottom.constant = r.origin.y+78;
    else if(IS_IPHONE_5)
      distanceFromBottom.constant = r.origin.y+183;
  }];
}

上面的代码非常完美.我不明白为什么我需要为iPhone6添加+78或为iPhone5添加183.这两个值我带来了反复试验.如果我不添加这些,textView扩展到键盘下方.请帮我解开这个谜.

Answer 1

在viewWillAppear方法中,添加以下内容:

- (void) viewWillAppear:(BOOL)paramAnimated{
    [super viewWillAppear:paramAnimated];

    [[NSNotificationCenter defaultCenter] 
        addObserver:self 
           selector:@selector(handleKeyboardDidShow:) 
               name:UIKeyboardDidShowNotification object:nil];

    [[NSNotificationCenter defaultCenter]
        addObserver:self
           selector:@selector(handleKeyboardWillHide:)     
               name:UIKeyboardWillHideNotification object:nil];    
}

然后实现通知中心的两种方法,如下所示:

- (void) handleKeyboardDidShow:(NSNotification *)paramNotification{

    NSValue *keyboardRectAsObject =
        [[paramNotification userInfo] 
            objectForKey:UIKeyboardFrameEndUserInfoKey];

    CGRect keyboardRect = CGRectZero;
    [keyboardRectAsObject getValue:&keyboardRect];

    yourTextView.contentInset =
        UIEdgeInsetsMake(0.0f,
                         0.0f,
                         keyboardRect.size.height,
                         0.0f);
}

而另一个像:

- (void) handleKeyboardWillHide:(NSNotification *)paramNotification{

    yourTextView.contentInset = UIEdgeInsetsZero;
}

它适用于所有设备;)

Answer 2

Swift /修改版

使用上面的内容,我做了一些调整,以便在键盘显示和隐藏时使用NSLayoutConstraint更改高度constant属性.如果您旋转设备,这也适用.

1.设置TextView约束

然后控制从您的高度约束拖出一个出口到该类.

2.添加以下内容

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        NSNotificationCenter.defaultCenter().addObserver(self, selector:#selector(SkillDescriptionViewController.keyboardWillShowHandle(_:)), name: UIKeyboardDidShowNotification, object: nil)

        NSNotificationCenter.defaultCenter().addObserver(self, selector:#selector(SkillDescriptionViewController.keyboardWillHideHandle), name: UIKeyboardWillHideNotification, object: nil)

    }


    func keyboardWillShowHandle(note:NSNotification) {
        guard let keyboardRect = note.userInfo![UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
        let kbFrame = keyboardRect.CGRectValue()
        tvHeight.constant = -kbFrame.height
        view.layoutIfNeeded()
    }

    func keyboardWillHideHandle() {
        tvHeight.constant = 0
        view.layoutIfNeeded()
    }