android javascript 调用activity

WebView 里有一个 addJavascriptInterface (Object obj, String interfaceName)方法，object为一个实例对象，你想用javascript调用的函数写在这代码如下：

package com.webview;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.webkit.JsResult;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.Toast;

public class MainActivity 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.addJavascriptInterface(new DemoJavaScriptInterface(), "demo");

        mWebView.loadUrl("http://192.168.1.201:8080/java.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()");
                	Toast.makeText(getBaseContext(), "123", Toast.LENGTH_SHORT).show();
                }
            });

        }
    }

    /**
     * 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;
        }
        
    }
}

 在html里调用写法如下：

<a onClick="window.demo.clickOnAndroid()">click me</a>