Tap navigation bar to scroll to top

I have a really long UIWebView, and I need to add a way for the user to tap the UINavigationBar to 开发者_StackOverflowscroll to top (something like the Facebook app, where it's little glow when you tap).

How can I do this?

In iOS5, you can now access the UIScrollView directly, allowing you to scroll to top.

[webView.scrollView scrollRectToVisible:animated:]

That should take care of everything that you need.

You could use javascript to scroll the web view to the top. You could execute the javascript from the Objective-C side using

- (NSString *)stringByEvaluatingJavaScriptFromString:(NSString *)script