尝试添加为子视图时，ScrollView 不起作用

Question

我的滚动视图有问题！我有一个名为 Rootview 的视图，我想将三个子视图添加到滚动视图中。当我将滚动视图添加为子视图时，中间视图和三个子视图消失了。这是我的代码。根视图（整个窗口）和滚动视图是出口。

UIView *middleView = [[UIView alloc] initWithFrame:CGRectMake(0, 218, 2024, 218)];
[middleView setBackgroundColor: [UIColor yellowColor]];
[RootView addSubview:middleView];

//create new views for sap systems beginning from left

UIView *firstSystem1 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 300, 218)];
[firstSystem1 setBackgroundColor: [UIColor grayColor]];
[middleView addSubview:firstSystem1];

UIView *secondSystem1 = [[UIView alloc] initWithFrame:CGRectMake(305, 0, 300, 218)];
[secondSystem1 setBackgroundColor: [UIColor grayColor]];
[middleView addSubview:secondSystem1];

UIView *thirdSystem1 = [[UIView alloc] initWithFrame:CGRectMake(610, 0, 300, 218)];
[thirdSystem1 setBackgroundColor: [UIColor grayColor]];
[middleView addSubview:thirdSystem1];




CGSize scrollViewContentSize1 = CGSizeMake(2024, 218);

 [middleScrollView setContentSize:scrollViewContentSize1];
[middleScrollView addSubview:middleView];

谁能帮我解决这个问题？

Answer 1

问题是你没有在任何地方添加你的middleScrollView

改变这个

[RootView addSubview:middleView];

为此

[RootView addSubview:middleScrollView];