//此前要遵循UITextFieldDelegate代理。并且设置该文本框为当前控制器的代理

//开始编辑的时候让整个view的高度网上移动

- (void)textFieldDidBeginEditing:(UITextField *)textField

{

    [UIView animateWithDuration:0.3f animations:^{

        CGRect curframe = self.view.frame; //不能直接修改frame的y值。需要先将其取出，然后再赋值回去

        curframe.origin.y -= ;

        self.view.frame = curframe;

    }];

}

//当结束编辑的时候，又将整个view退回到原来的位置

- (void)textFieldDidEndEditing:(UITextField *)textField

{

    [UIView animateWithDuration:0.3f animations:^{

        CGRect curframe = self.view.frame;

        curframe.origin.y += ;

        self.view.frame = curframe;

    }];

}