iOS获取键盘高度代码

//增加监听，当键盘出现或改变时收出消息
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];

    //增加监听，当键退出时收出消息
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification
                                               object:nil];


     //当键盘出现或改变时调用
      - (void)keyboardWillShow:(NSNotification *)aNotification
     {
     //获取键盘的高度
    NSDictionary *userInfo = [aNotification userInfo];
    NSValue *aValue = [userInfo      objectForKey:UIKeyboardFrameEndUserInfoKey];
CGRect keyboardRect = [aValue CGRectValue];
int height = keyboardRect.size.height;

UIView *view = [self viewWithTag: 100];
CGFloat heightView = view.frame.origin.y;

view.frame = CGRectMake(0, heightView - height, view.frame.size.width, view.frame.size.height);
}

   //当键退出时调用
   - (void)keyboardWillHide:(NSNotification *)aNotification{

}