iOS开发中隐藏键盘的代码

参考：http://blog.devtang.com/blog/2012/03/15/10-most-common-questions-on-stackoverflow-201203/

设置textField的代理，不需要使用ScrollField，代码如下：

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    if ([textField isEqual:self.textFiled]) {
        if (self.view.frame.origin.y >= 0) {
            [self setViewMoveUp:YES];
        }
    }
}

- (void)setViewMoveUp:(BOOL)moveUp
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.5];

    CGRect rect = self.view.frame;
    if (moveUp) {
        rect.origin.y -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
    } else {
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    }
    self.view.frame = rect;
    [UIView commitAnimations];
}