为什么我用下面的代码添加图片到UIscrollView不成功?显示的是一个空白屏幕。
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(self.scrollView.frame.size.width * 1, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height)];
imageView.backgroundColor = [UIColor redColor];
[imageView setImage:[UIImage imageNamed:@"placeholder.png"]];
[self.scrollView addSubview:imageView];
self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * self.urlArray.count, self.scrollView.frame.size.height);