为什么在WEBVIEW中调用JAVASCRIPT不管用？

lu188887 2011-05-19 06:10:13

在这个HTML中声明了一个testEcho函数，在TianMap.java中loadUrl("javascript:testEcho()")的时候是不会调用这个函数的，只有将该语句放在Button的点击响应函数中才会调用！！请问这是为什么？

demo.html代码如下：

<!DOCTYPE html "-//W3C//DTD XHTML 1.0 Strict//EN"

 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

  <head>

    <meta http-equiv="content-type" content="text/html; charset=utf-8"/>

    <title>GeoSurf Maps JavaScript API Example</title>

    <script src="http://www.tianditu.com/guide/lib/GeoSurfJSAPI.js"

            type="text/javascript"></script>

    <script src="http://www.tianditu.com/guide/2d_samples/sampleCfg.js"

            type="text/javascript"></script>

    <script type="text/javascript">

	   function initialize() {

	     var map = new GeoSurf.PortalMap("frist_map");

	     map.loadLayerGroup(vectorGroup);

	     map.setCenter(new GeoSurf.LonLat(39.92361, 116.3809), 10); 

	     var chinaBounds = new GeoSurf.Bounds(73.30,17,135.65,52.32);

	     

	     map.zoomToExtent(chinaBounds);

	     alert("initialize");

	     

	   }

	  

    </script>

    <script type="text/javascript">

    function testEcho() {

	

		alert("testEcho");



   	}

    </script>

  </head>

  <body onload="initialize()">

    <div id="frist_map" style="width: 500px; height: 300px"></div>

  </body>

</html>

package com.TianMap;



import android.app.Activity;

import android.app.AlertDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.net.ConnectivityManager;

import android.net.NetworkInfo;

import android.os.Bundle;

import android.util.DisplayMetrics;

import android.view.View;

import android.webkit.*;

import android.widget.Button;

import android.widget.Toast;



public class TianMap extends Activity {

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

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        

       init();

        

		

    }

  

    

    

    	private boolean CheckNetWork() {

    		 Context context = getApplicationContext();  

    	ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

    	NetworkInfo network = cm.getActiveNetworkInfo();

    	if (network != null) {

    	return network.isAvailable();

    	}

    	else{

    		return false;

    	}

    	}

    	

    

    private void init(){

    	if(CheckNetWork()){

    		DisplayMetrics metrics = new DisplayMetrics();



    		final WebView mWebView= (WebView)findViewById(R.id.webview);

    	    mWebView.getSettings().setJavaScriptEnabled(true);

    	    

    		

    		mWebView.setWebChromeClient(new WebChromeClient() {

    			public boolean onJsAlert(WebView view, String url, String message,   JsResult result) {

    		                //Required functionality here

    		                return super.onJsAlert(view, url, message, result);

    		       }});

    	    try{

    	    	

    	    	 

    	    	mWebView.loadUrl("file:///android_asset/demo.html"); 

    	    	 mWebView.loadUrl("javascript:testEcho()");			//这句为什么不调用JS函数呢？？？？？

    	    	 Button mButton = (Button) findViewById(R.id.button1);     

    	         //给button添加事件响应,执行JavaScript的fillContent()方法     

    	         mButton.setOnClickListener(new Button.OnClickListener() {     

    	             public void onClick(View v) {     

    	                 mWebView.loadUrl("javascript:testEcho()");    			//这里的可以调用。。 

    	             }     

    	         });     

    	    	

    	    	

    	 

    	    	

    	    	Toast.makeText(this, "ooo", Toast.LENGTH_SHORT).show();

    	    	}

    	    catch (Exception ex) {

    	        ex.printStackTrace();

    	    }

    	}

    	else{

    		new AlertDialog.Builder(this)

            .setMessage("网络链接错误，点击确定退出")

            .setPositiveButton("确定",

                new DialogInterface.OnClickListener(){

                    public void onClick(DialogInterface dialoginterface, int i){

                     

                    	android.os.Process.killProcess(android.os.Process.myPid());

                }

            })

            .show();

    	}

    	

    }

   

}

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hotkarriver 2011-08-08

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mWebView.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
mHandler.post(new Runnable() {
public void run() {
mWebView.loadUrl("javascript:testEcho()");
}
});
super.onPageFinished(view, url);
}
}

ZogYi 2011-08-02

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楼主，重写onPageFinish是如何解决的？
如何重写？

AspireHouse 2011-05-23

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mWebView.loadUrl("file:///android_asset/demo.html");
loadUrl是一个异步过程，如果你在它下面直接调用mWebView.loadUrl("javascript:testEcho()");
它此时还没生成dom树，调用了没效果也正常。
最好重写WebView的onPageFinish（）方法，就应该有效果了，顾名思义就是等页面加载完成再执行那个js函数

lu188887 2011-05-20