互联网连接时是否无法缓存WebView或互联网未连接时是否显示缓存？

Question

我在我的应用中实现了webview，我希望在没有网络离线时加载缓存，但这对我不起作用。这是我的代码：

....

    pageInfo = (WebView)findViewById(R.id.pageInfo);
            pageInfo.getSettings().setJavaScriptEnabled(true);
            pageInfo.getSettings().setLoadWithOverviewMode(true);
            pageInfo.getSettings().setUseWideViewPort(true);
            pageInfo.getSettings().setBuiltInZoomControls(true);
            pageInfo.getSettings().setSupportZoom(true);
            pageInfo.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
            pageInfo.setScrollbarFadingEnabled(true);
            pageInfo.getSettings().setLoadsImagesAutomatically(true);
            pageInfo.getSettings().setAppCacheMaxSize(1024 * 1024 * 100);
            pageInfo.getSettings().setAppCacheEnabled(true);


if ( !isNetworkAvailable() ) { // loading offline
            pageInfo.getSettings().setCacheMode( WebSettings.LOAD_CACHE_ELSE_NETWORK );
            Log.w("tag", "offline");
        }
        try {
            pageInfo.loadUrl(Variabel.link_detail_post);
        } catch (Exception e) {
            e.printStackTrace();


         }

....

private boolean isNetworkAvailable() {
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService( CONNECTIVITY_SERVICE );
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null;
    }

这是我的许可

 <!--  permission -->
        <uses-permission android:name="android.permission.INTERNET" />
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
        <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
        <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
        <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

那怎么解决这个问题？谢谢...对不起我的英语和语法