I have created an application in which i am using webview and loading a simple static html page. I am calling a java script function from activity but i am unable to call a function from java script. I have tried few of the link , but it didn't work .
Javascript Callback function pass to Android
I cannot call an android function from javascript
Here is my code. Thank you in advance.
acitivity_main.xml
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Call JavaScript Function"
android:onClick="callJavaScript" />
<WebView
android:id="@+id/myWebView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
index.html
<html>
<head>
<script type="text/javascript">
function displayMessage(){
document.getElementById('test1').innerHTML = 'This is from java script.';
Android.returnResult();
}
</script>
</head>
<body>
<h1 id="test1">Hello World</h1>
</body>
</html>
Main activity has following two functions .
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myWebView = (WebView) this.findViewById(R.id.myWebView);
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.addJavascriptInterface(new JavaScriptHandler(this), "Android");
myWebView.loadUrl("file:///android_asset/index.html");
}
public void callJavaScript(View view) {
Log.v(null, "Calling java Script");
myWebView.loadUrl("javascript:displayMessage()");
}
This is the JavaScriptHandler class
public class JavaScriptHandler {
Context mContext;
public JavaScriptHandler(Context context) {
mContext = context;
}
public void returnResult() {
Log.v(null, "result received");
}
}
I have created an application in which i am using webview and loading a simple static html page. I am calling a java script function from activity but i am unable to call a function from java script. I have tried few of the link , but it didn't work .
Javascript Callback function pass to Android
I cannot call an android function from javascript
Here is my code. Thank you in advance.
acitivity_main.xml
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Call JavaScript Function"
android:onClick="callJavaScript" />
<WebView
android:id="@+id/myWebView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
index.html
<html>
<head>
<script type="text/javascript">
function displayMessage(){
document.getElementById('test1').innerHTML = 'This is from java script.';
Android.returnResult();
}
</script>
</head>
<body>
<h1 id="test1">Hello World</h1>
</body>
</html>
Main activity has following two functions .
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myWebView = (WebView) this.findViewById(R.id.myWebView);
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.addJavascriptInterface(new JavaScriptHandler(this), "Android");
myWebView.loadUrl("file:///android_asset/index.html");
}
public void callJavaScript(View view) {
Log.v(null, "Calling java Script");
myWebView.loadUrl("javascript:displayMessage()");
}
This is the JavaScriptHandler class
public class JavaScriptHandler {
Context mContext;
public JavaScriptHandler(Context context) {
mContext = context;
}
public void returnResult() {
Log.v(null, "result received");
}
}
- Kindly add alert statements in your javascript method to see if you javascript method is getting called properly. Otherwise I dont see any problem in your implementation. – Arunkumar Commented Nov 27, 2013 at 13:54
- Thank you for replying , i have added a line to change the html text when java script is getting called and it was working anyway i got the answer looks like i had to use the annotation. – Rana Ranvijay Singh Commented Nov 28, 2013 at 4:51
1 Answer
Reset to default 5Make it
@JavascriptInterface
public void returnResult() {
Log.v(null, "result received");
}
This annotation allows exposing methods to JavaScript.