[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(transformView:) name:UIKeyboardWillChangeFrameNotification object:nil];//键盘的弹出

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

//键盘的消失

//弹出键盘UIView

-(void)transformView:(NSNotification*)aNSNotification{

    //获取键盘弹出前的Rect

    NSValue*keyBoardBeginBounds=[[aNSNotification userInfo]objectForKey:UIKeyboardFrameBeginUserInfoKey];

    CGRect beginRect=[keyBoardBeginBounds CGRectValue];

    //获取键盘弹出后的Rect

    NSValue*keyBoardEndBounds=[[aNSNotification userInfo]objectForKey:UIKeyboardFrameEndUserInfoKey];

    CGRect  endRect=[keyBoardEndBounds CGRectValue];

    //获取键盘位置变化前后纵坐标Y的变化值

    CGFloat deltaY=endRect.origin.y-beginRect.origin.y;

    NSLog(@"看看这个变化的Y值:%f",deltaY);

    //在0.25s内完成self.view的Frame的变化，等于是给self.view添加一个向上移动deltaY的动画

    [UIView animateWithDuration:0.25f animations:^{

        self.popView.frame = CGRectMake(0, -50, kScreenWidth, kScreenHeight);

    }];

}

//退出键盘UIView

-(void)keyboardWillHide:(NSNotification*)aNSNotification{

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:0.25];

    [UIView setAnimationCurve:7];

    self.popView.frame = CGRectMake(0, 0, kScreenWidth, kScreenHeight);

    [UIView commitAnimations];

}