如何显示uiWebView的滚动指示器

从iOS 5.0开始,现在可以通过访问“ScrollView”属性自定义uiWebView的滚动行为,以实现所需的功能:

 [webView.scrollView flashScrollIndicators];

没有真正的方法可以通过已发布的API来实现这一点,但是我认为在这种情况下,可以猜测 UIScrollView 子视图,只要您确保您的应用程序不会崩溃,如果您找不到 UISCLVIEW :

UIView* scrollView = [webView.subviews objectAtIndex:0];
if ([scrollView isKindOfClass:[UIScrollView class]) {
  [((UIScrollView*)scrollView) flashScrollIndicators];
} else {
  // If Apple changes the view hierarchy you won't get
  // a flash, but that doesn't matter too much
}

编辑: 上面的内容不起作用,因为 UIWebView 是一个 UIScroller 不是 UISCLVIEW (我的记忆可能在捉弄我)。也许可以尝试以下方法?

UIView* uiScroller = [webView.subviews objectAtIndex:0];
if ([uiScroller respondsToSelector:@selector(displayScrollerIndicators)]) {
  [((UIScrollView*)uiScroller) performSelector:@selector(displayScrollerIndicators)];
} else {
  // If Apple changes the view hierarchy you won't get
  // a flash, but that doesn't matter too much
}