<pre><code>
监听键盘
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];
//执行的方法
-(void)keyboardWillChangeFrame:(NSNotification *)noti{
//1.获取动画时间
CGFloat time=[noti.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGFloat endY=[noti.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue].origin.y;
//获取偏移值
//根据textField的位置调整偏移值
CGFloat offset=(endY-screenH)/2;
[UIView animateWithDuration:time/2 animations:^{
self.view.transform=CGAffineTransformMakeTranslation(0, offset);
}];
}