Question

155

using javascript in android webview

rated 0 times [ 162] [ 7] / answers: 1 / hits: 94467 / 12 Years ago, sun, may 6, 2012, 12:00:00

I'm trying to start an activity from a javascript interface in my webview.
The example shows a toast. How could i call a class instead of a toast?

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();

}

}

this for the html page.

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



<script type=text/javascript>

function showAndroidToast(toast) {

    Android.showToast(toast);

}

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trevionbronsonr

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1 Year ago

answered 12 Years ago darennevina · Accepted Answer

You have to first register the JavaScriptInterface on your webview.
JavaScriptInterFace can be a inner class as shown below. This class will have a function that you can call from html page( via javaScript ) and inside this function you can write code to change activity.

Here is the working solution for you:

public class JavascriptInterfaceActivity extends Activity {

    /** Called when the activity is first created. */





    WebView wv;



    JavaScriptInterface JSInterface;



    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        wv = (WebView)findViewById(R.id.webView1);



        wv.getSettings().setJavaScriptEnabled(true);

        // register class containing methods to be exposed to JavaScript



        JSInterface = new JavaScriptInterface(this);

        wv.addJavascriptInterface(JSInterface, JSInterface); 



        wv.loadUrl(file:///android_asset/myPage.html);



    }





    public class JavaScriptInterface {

        Context mContext;



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

        JavaScriptInterface(Context c) {

            mContext = c;

        }



        @android.webkit.JavascriptInterface

        public void changeActivity()

        {

            Intent i = new Intent(JavascriptInterfaceActivity.this, nextActivity.class);

            startActivity(i);

            finish();

        }

    }

}

Here is the html page

<html>

<head>

<script type=text/javascript>

function displaymessage()

{

JSInterface.changeActivity();

}

</script>

</head>



<body>

<form>

<input type=button value=Click me! onclick=displaymessage() />

</form>

</body>

</html>

Hope this helps...