在网页视图中限制打开一些网站

将类设置给webView，webView.delegate = self。然后还需要UIViewController

代码：

UIViewController <UIWebViewDelegate>

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    if ([request.URL.absoluteString rangeOfString:@"google"].length != 0) {

        return NO;  
    }else {
        return YES;
    }
}