android 的webkit的api的开放程度还是非常不错，java可以和webview内的javascript很好的交互。下面的小例子可以说明这一点。
先看我们的html文档：
- <html>
- <script language="javascript">
- /* This function is invoked by the activity */
- function wave() {
- alert("1");
- document.getElementById("droid").src="android_waving.png";
- alert("2");
- }
- </script>
- <body>
-
- <a onClick="window.demo.clickOnAndroid()"><div style="width:80px;
- margin:0px auto;
- padding:10px;
- text-align:center;
- border:2px solid #202020;" >
- <img id="droid" src="android_normal.png"/><br>
- Click me!
- </div></a>
- </body>
- </html>
Click me!
再看我们的java 代码。
- public class WebViewDemo extends Activity {
-
- private static final String LOG_TAG = "WebViewDemo";
-
- private WebView mWebView;
-
- private Handler mHandler = new Handler();
-
- @Override
- public void onCreate(Bundle icicle) {
- super.onCreate(icicle);
- setContentView(R.layout.main);
- mWebView = (WebView) findViewById(R.id.webview);
-
- WebSettings webSettings = mWebView.getSettings();
- webSettings.setSavePassword(false);
- webSettings.setSaveFormData(false);
- webSettings.setJavaScriptEnabled(true);
- webSettings.setSupportZoom(false);
-
- mWebView.setWebChromeClient(new MyWebChromeClient());
-
- mWebView.addJavascriptInterface(new DemoJavaScriptInterface(), "demo");
-
- mWebView.loadUrl("file:///android_asset/demo.html");
- }
-
- final class DemoJavaScriptInterface {
-
- DemoJavaScriptInterface() {
- }
-
-
-
-
-
- public void clickOnAndroid() {
- mHandler.post(new Runnable() {
- public void run() {
- mWebView.loadUrl("javascript:wave()");
- }
- });
-
- }
- }
-
-
-
-
-
- final class MyWebChromeClient extends WebChromeClient {
- @Override
- public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
- Log.d(LOG_TAG, message);
- result.confirm();
- return true;
- }
-
- }
- }
public class WebViewDemo extends Activity { private static final String LOG_TAG = "WebViewDemo"; private WebView mWebView; private Handler mHandler = new Handler(); @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); mWebView = (WebView) findViewById(R.id.webview); WebSettings webSettings = mWebView.getSettings(); webSettings.setSavePassword(false); webSettings.setSaveFormData(false); webSettings.setJavaScriptEnabled(true); webSettings.setSupportZoom(false); mWebView.setWebChromeClient(new MyWebChromeClient()); mWebView.addJavascriptInterface(new DemoJavaScriptInterface(), "demo"); mWebView.loadUrl("file:///android_asset/demo.html"); } final class DemoJavaScriptInterface { DemoJavaScriptInterface() { } /** * 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()"); } }); } } /** * 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) { Log.d(LOG_TAG, message); result.confirm(); return true; } }} WebView 的addJavascriptInterface函数就可以实现彼此的交互。