iOS监听键盘事件

1.先设置监听者以及监听对象和事件

<pre>
<code class='objectivec hljs'>
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];

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

2.实现监听方法

• (void)keyboardWillShow:(NSNotification *)notification {
  NSDictionary *userInfo = [notification userInfo];
  // 获取键盘的frame
  CGRect keyboardFrame = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
  // 获取键盘的动画时间
  NSTimeInterval animationDuration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
  // do something
  }

• (void)keyboardWillHide:(NSNotification *)notification {
  // do something
  }
  </code></pre>