在安卓的webview中，document.getElementsByName在某些网站上不起作用

WebView myWebView = (WebView) findViewById(R.id.webview);
WebSettings webSettings = myWebView.getSettings();
webSettings.setJavaScriptEnabled(true);

myWebView.setWebViewClient(new WebViewClient() {
    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);
        // 在这里执行document.getElementsByName
        myWebView.evaluateJavascript("(function() { return document.getElementsByName('elementName'); })();", new ValueCallback<String>() {
            @Override
            public void onReceiveValue(String value) {
                // 处理返回的结果
            }
        });
    }
});

myWebView.evaluateJavascript("(function() { return window.frames[0].document.getElementsByName('elementName'); })();", new ValueCallback<String>() {
    @Override
    public void onReceiveValue(String value) {
        // 处理返回的结果
    }
});