// Do any additional setup after loading the view, typically from a nib.
} //显示
-(void)keyboarShow:(NSNotification *)notification{
//获取键盘的高度
CGRect rect =[notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
//计算出 textView的height
CGRect textViewRect=_myTextView.frame;
CGFloat height=textViewRect.size.height-rect.size.height;
textViewRect.size.height=height;
[UIView animateWithDuration:.2 animations:^{
self.myTextView.frame=textViewRect;
}];