Use javascript in WebView in Android

 

By default, javascript cannot be used in WebView. You can write the following code:

 

WebView myWebView = (WebView) findViewById (R. id. webview );

WebSettings webSettings = myWebView. getSettings ();

WebSettings. setJavaScriptEnabled (true );

 

Then you can use it.

 

Bind javascript and Android code:

 

For example, you can create a class in your application:

 

Public class JavaScriptInterface {

Context mContext;

 

/** Instantiate the interface and set the context */

JavaScriptInterface (Context c ){

MContext = c;

}

 

/** Show a toast from the web page */

Public void showToast (String toast ){

Toast. makeText (mContext, toast, Toast. LENGTH_SHORT). show ();

}

}

 

Binds javascript. The interface name is Android.

 

WebView webView = (WebView) findViewById (R. id. webview );

WebView. addJavascriptInterface (new JavaScriptInterface (this), "Android ");

 

Then write in your HTML code:

 

<Input type = "button" value = "Say hello" onClick = "showAndroidToast ('Hello Android! ') "/>

 

<Script type = "text/javascript">

Function showAndroidToast (toast ){

Android. showToast (toast );

}

</Script>

 

Note: The bound javascript runs in another thread, which is not the same as the thread that created it.

 

Processing page navigation:

 

By default, When you click the link to your WebView page, connect to the URL. You can use the following method to connect to your own WebView.

 

WebView myWebView = (WebView) findViewById (R. id. webview );

MyWebView. serWebViewClient (new WebViewClient ());

 

To control more click connections, you can override the shouldOverrideUrlLoading () method to create your own WebViewClient:

 

Private class MyWebViewClient extends WebViewClient {

@ Override

Public boolean shouldOverrideLoading (WebView view, String url ){

If (Uri. parse (url). getHost (). equals ("www.example.com ")){

// This is my web site, so do not override; let my WebView load the page

Return false;

}

// Otherwise, the link is not for a page on my site, so launch another Activity that handles URLs

Intent intent = new Intent (Intent. ACTION_VIEW, Uri. parse (url ));

StartActivity (intent );

Return true;

}

}

 

You can access the history page in the following ways:

 

Public boolean onKeyDown (int keyCode, KeyEvent event ){

// Check if the key event was the BACK key and if there's history

If (keyCode = KeyEvent. KEYCODE_BACK) & myWebView. canGoBack (){

MyWebView. goBack ();

Return true;

}

// If it wasn' t the BACK key or there's no web page history, bubble up to the default

// System behavior (probably exit the activity)

Return super. onKeyDown (keyCode, event );

}

From: column of Yan Longan