在android中显示webview的缓存版本-displayingcachedversionofwebviewinandroid

6  

Try to find out the network status using

尝试找出使用的网络状态

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

(Detect whether there is an Internet connection available on Android)

(检测Android上是否有互联网连接)

This also needs

这也需要

in your AndroidManifest.xml

在你AndroidManifest.xml

Now you can set the cache behaviour either to LOAD_CACHE_ONLY or to LOAD_NO_CACHE, depending on whether a network connection is available, with

现在，您可以将缓存行为设置为LOAD_CACHE_ONLY或LOAD_NO_CACHE，这取决于网络连接是否可用

webview.getSettings().setCacheMode(...)

2  

I think a good solution would be to use LOAD_NORMAL and onReceivedError Navigate BACK. I think this will load the cache according to the documentation (not sure if I remember correctly) but be carefull no to get stuck in an infinite loop

我认为一个好的解决方案是使用LOAD_NORMAL和onReceivedError返回。我认为这将根据文档加载缓存(不确定我是否记得正确)，但是要小心不要陷入无限循环中。

It is weird.. According to the documentation:

这是奇怪的。根据文档:

Override the way the cache is used. The way the cache is used is based on the navigation option. For a normal page load, the cache is checked and content is re-validated as needed. When navigating back, content is not revalidated, instead the content is just pulled from the cache. This function allows the client to override this behavior.

重写缓存的使用方式。使用缓存的方式基于导航选项。对于正常的页面加载，缓存被检查，并且根据需要重新验证内容。当导航回来时，内容不会被重新验证，而是从缓存中提取内容。此函数允许客户端重写此行为。

However the behavior you want does not seem to be one of these:

然而，你想要的行为似乎并不是其中之一:

1. LOAD_CACHE_ELSE_NETWORK

   Use cache if content is there, even if expired (eg, history nav) If it is not in the cache, load from network.

   如果内容存在，使用缓存，即使过期(例如，历史资产净值)，如果不在缓存中，从网络加载。

2. LOAD_CACHE_ONLY

   LOAD_CACHE_ONLY

   Don't use the network, load from cache only.

   不要使用网络，只从缓存加载。

3. LOAD_DEFAULT

   LOAD_DEFAULT

   Default cache usage pattern

   默认的缓存使用模式

4. LOAD_NORMAL

   LOAD_NORMAL

   Normal cache usage pattern

   正常的缓存使用模式

5. LOAD_NO_CACHE

   LOAD_NO_CACHE

   Don't use the cache, load from network

   不要使用缓存，从网络加载

I do not know if you can subclass the WebView to get the desired flow.

我不知道您是否可以子类化WebView来获得所需的流。

1  

Does it not work if you simply let the browser handle this? Specify the manifest in the HTML tag like this:

如果你只是让浏览器来处理这个问题，它会不会工作?在HTML标记中指定清单如下所示:

...and the browser should automatically use it when there's no connection available, you shouldn't need to change any settings at all.

…当没有连接时，浏览器应该自动使用它，你根本不需要改变任何设置。

0  

You should firstly set permission in your AndroidManifest.xml

您应该首先在AndroidManifest.xml中设置权限

Then check internet network is on or off by :

然后查查互联网网络是开还是关:

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

At last add below code with your Webview object

最后用Webview对象添加下面的代码

webView = (WebView) findViewById(R.id.WebEngine);
        webView.getSettings().setAppCacheMaxSize( 5 * 1024 * 1024 ); // 5MB
        webView.getSettings().setAppCachePath( getApplicationContext().getCacheDir().getAbsolutePath() );
        webView.getSettings().setAllowFileAccess( true );
        webView.getSettings().setAppCacheEnabled( true );
        webView.getSettings().setJavascriptEnabled( true );
        webView.getSettings().setCacheMode( WebSettings.LOAD_DEFAULT );
        if ( !isNetworkAvailable() ) { // loading offline
            webView.getSettings().setCacheMode( WebSettings.LOAD_CACHE_ELSE_NETWORK );
        }
webView.loadUrl("http://www.geekonjava.blogspot.com/?m=1");

Thats it if your internet is on your webpage open normal version and saved in cached and if your internet is off then it automatically open in cached version.

如果你的互联网在你的网页上打开正常的版本，并保存在缓存里，如果你的互联网关闭了，它会自动打开缓存的版本。