缓存页面的最后一个视图以用于离线模式

Question

我的安卓缓存系统有问题 我想要的是为android缓存我的最后一个视图并在离线模式下打开它但是在在线的情况下想要实时页面而不是缓存的页面 如果我们以任何价格网站为例 http://www.oil-price.net/ 这是我的java类代码

public class Petroleum_price extends Fragment {


    public Petroleum_price() {
        // Required empty public constructor
    }

    Context context;
    WebView mwebView;


    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.activity_petroleum_price, container, false);
        context = container.getContext();
        mwebView = new WebView(context);
        mwebView = (WebView) v.findViewById(R.id.webView);
        WebSettings webSettings = mwebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mwebView.getSettings().setAppCachePath( getActivity().getApplicationContext().getCacheDir().getAbsolutePath() );
        mwebView.getSettings().setAppCacheEnabled(true);
        mwebView.getSettings().setAllowFileAccess( true );
        webSettings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);
        webSettings.setUseWideViewPort(true);
        webSettings.setSaveFormData(true);
        CookieManager.getInstance().setAcceptCookie(true);
        if ( !isNetworkAvailable() ) { // loading offline
            mwebView.getSettings().setCacheMode( WebSettings.LOAD_CACHE_ELSE_NETWORK );
        }

        mwebView.loadUrl( "http://www.oil-price.net/" );
        return v;
    }

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

Answer 1

您可以将此代码用于您的 WebView 实现

webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setAppCacheMaxSize( 10 * 1024 * 1024 );
webView.getSettings().setAppCachePath( getCacheDir().getAbsolutePath() );
webView.getSettings().setAllowFileAccess( true );
webView.getSettings().setAppCacheEnabled( true );
webView.getSettings().setJavaScriptEnabled( true );
webView.getSettings().setCacheMode( WebSettings.LOAD_DEFAULT );
if ( !isNetworkAvailable() ) {
    webView.getSettings().setCacheMode( WebSettings.LOAD_CACHE_ELSE_NETWORK );
}
webView.loadUrl( "http://www.google.com" );

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

并在您的清单中使用此代码

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

基于WebView load website when online, load local file when offline的回答