Xcode 取消或结束UIScrollView

我编写了一个代码，当按下按钮时调用UIScrollView。问题是，即使按下另一个按钮，它也会保留在屏幕上。我不知道该如何结束或驳回这件事

（iAction）onClickSize:（id）发送方{

viewSizePrint.hidden=YES；
scrlView.contentSize=CGSizeMake（1500214）；
对于（inti=0；iThanks Aaron。我以前有过那个代码，它抛出了一个异常。下面是它说的int main（intargc，char*argv[]）{@autoreleasepool{return UIApplicationMain（argc，argv，nil，NSStringFromClass（[AppDelegate class]）；}}线程1:SIGABRT
viewSizePrint.hidden = YES;
scrlView.contentSize = CGSizeMake(1500, 214);

for (int i=0; i<20; i++) {
    UIImageView *imgView = [[UIImageView alloc] initWithFrame:CGRectMake(158*i+22, 2, 154, 210)];
    imgView.tag = i+10;
    [scrlView addSubview:imgView];

    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    [btn setBackgroundImage:[UIImage imageNamed:[NSString stringWithFormat:@"layout%d_thumbnail", i+1]] forState:UIControlStateNormal];
    btn.frame = CGRectMake(158*i+30, 10, 138, 194);
    btn.tag = i;
    [btn addTarget:self action:@selector(onClickTheme:) forControlEvents:UIControlEventTouchUpInside];
    [scrlView addSubview:btn];
}

[self refreshTheme:[AppDelegate sharedAppDelegate].shrTheme];

}

[scrlView removeFromSuperview];
scrlView = nil;