Question

我使用带有来自XIB的几个子视图的UIViewController（ViewController的视图），它们是在使用UISegmentedControl之间选择的。其中一个视图包含UIScrollView。问题是UIScrollView无法滚动第一次添加此子视图。如果我选择另一个细分/视图，然后再选择UIScrollView，那么它现在可以滚动。

仅在IB中添加UIScrollView。这是视图的一些代码和MainViewController.m中的UISegmentedControl

- (void)viewDidLoad
{
[super viewDidLoad];

nameSubViewController = [[NameSubViewController alloc] initWithNibName:@"NameSubViewController" bundle:nil];
nameSubView = (NameSubView *)[nameSubViewController view];

priceSubViewController = [[PriceSubViewController alloc] initWithNibName:@"PriceSubViewController" bundle:nil];
priceSubView = (PriceSubView *)[priceSubViewController view];

[self.view addSubview:nameSubView];
currentView = nameSubView;
}

- (void) segmentAction:(id)sender
{
segmentedControl = sender;
if([segmentedControl selectedSegmentIndex] == 0) {
    [currentView removeFromSuperview];
    [self.view addSubview:nameSubView];
    currentView = nil;
    currentView = nameSubView;
}
if([segmentedControl selectedSegmentIndex] == 1) {
[currentView removeFromSuperview];
[self.view addSubview:priceSubView];
    currentView = nil;
    currentView = priceSubView;
}

在此代码中，假设段1（priceSubView）包含UIScrollView。如果我选择此细分，则UIScrollView不会对滚动作出反应，除非我再次选择细分0（nameSubView）并重新选择细分1。

导致此问题的原因及解决方法是什么？

Answer 1

如果您需要在第一次加载时滚动。您需要在firstLoad添加scrollView。您在更改段控件后添加滚动视图，这就是它不滚动的原因。看看吧。

更改viewDidLoad，如：

- (void)viewDidLoad
{
  [super viewDidLoad];

  nameSubViewController = [[NameSubViewController alloc] initWithNibName:@"NameSubViewController" bundle:nil];
  nameSubView = (NameSubView *)[nameSubViewController view];

  priceSubViewController = [[PriceSubViewController alloc] initWithNibName:@"PriceSubViewController" bundle:nil];
  priceSubView = (PriceSubView *)[priceSubViewController view];

  [self.view addSubview:priceSubView];
  currentView = priceSubView;
}

具有子视图的ViewController，UIScrollView第一次不可滚动

1 个答案: