UIWebView加载页面

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    if (!_loaded){
        _loaded = YES;
        return YES;
    }
    else{
        NSString *path=[[request URL] absoluteString];
        MainDetailViewController *mainDetailViewController = [[MainDetailViewController alloc]init];
        mainDetailViewController.urlString =  path;
        [self.navigationController pushViewController:mainDetailViewController animated:YES];
        return NO;
    }
}