WKWebView获取网页标题

NSString *titleJs = @"document.title";
[self.webView evaluateJavaScript:titleJs completionHandler:^(id result, NSError *error) {
    if (error == nil) {
        if (result != nil) {
            NSString *title = [NSString stringWithFormat:@"%@", result];
            YZLog(@"%@",title);
        }
    }
}];