在看懂这篇文章之前首先要有javascript基础。
(1) js调用android的方法：
wView. addJavascriptInterface (Object obj, String interfaceName);
是实例化一个对象，在html的js中调用，第二个参数是实例化对象的别名，如果要使用这个obj，则在js中使用的名字
就是interfaceName。
public class jsWebDemo extends Activity {
WebView wView；
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
wView = (WebView)findViewById(R.id.wv1);
WebSettings wSet = wView.getSettings();
wSet.setJavaScriptEnabled(true);
ProxyBridge pBridge = new ProxyBridge();
wView.addJavascriptInterface(pBridge, "AliansBridge");
wView.loadUrl("file:///android_asset/index.html");
}
private class ProxyBridge {
public int one () {
return 1;
}
}
}
来看一下index.html的内容：
<html>
<mce:script language="javascript"><!--
/* This function is invoked by the activity */
function wave() {
alert("1");
document.getElementById("droid").src="android_waving.png";
alert("2");
}
// --></mce:script>
<body>
<div id="output">Test page.</div>
<a onClick="window.demo.clickOnAndroid()">
<div style="width:100px;
margin:0px auto;
padding:10px;
text-align:center;
border:2px solid #202020;" >
<img id="droid" src="android_normal.png" mce_src="android_normal.png"/><br>
Click me!
</div>
</a>
<input type="submit" value="change to 1" onclick="document.getElementById('output').innerHTML
=AliansBridge.one()" />
</body>
</html>
这里的AliansBridge即是调用的JAVA对象。
要注意的是，如果你只有一个方法需要被js调用只new一个对象就行：
ProxyBridge pBridge = new ProxyBridge();
wView.addJavascriptInterface(pBridge, "AliansBridge");
如果你需要调用好多个方法，就要把整个android程序所在的类本身实例化传递进去：
wView.addJavascriptInterface(this, "AliansBridge");
(2) android调用js的方法：wView.setWebChromeClient (WebChromeClient client)
要用到Handler更新UI，Handler mHandler = new Handler()；
mWebView.addJavascriptInterface(new Object(){
/**
* This is not called on the UI thread. Post a runnable to invoke
* loadUrl on the UI thread.
*/
public void clickOnAndroid() {
mHandler.post(new Runnable() {
public void run() {
mWebView.loadUrl("javascript:wave()");
}
});
}
}, "demo");
同理，在html中必须有一个名为demo的对象调用clickOnAndroid()方法。
* Provides a hook for calling "alert" from javascript. Useful for
* debugging your javascript.
*/
final class MyWebChromeClient extends WebChromeClient {
@Override
public boolean onJsAlert(WebView view, String url, String message,
JsResult result) {
result.confirm();
return super.onJsAlert(view, url, message, result);
}
}