android中兑现JavaScript与Java之间实现互相调用
日期：2014-05-16 浏览次数：20466 次
webview提供了接口让javascript访问Java应用程序，WebView.addJavascriptInterface()方法就是实现交互接口的好东西呀！当然也是很危险的！看下面例子：
//main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android
"
??? android:orientation="vertical"
??? android:layout_width="fill_parent"
??? android:layout_height="fill_parent"
??? >
<EditText
?android:id="@+id/txt"
??? android:layout_width="fill_parent"
??? android:layout_height="wrap_content"
??? />
<Button
?android:id="@+id/btn"
??? android:layout_width="fill_parent"
??? android:layout_height="wrap_content"
??? android:text="Send To JavaScript"
??? />
<TextView
?android:id="@+id/show"
??? android:layout_width="fill_parent"
??? android:layout_height="wrap_content"
??? />
<WebView
?android:id="@+id/wv"
??? android:layout_width="fill_parent"
??? android:layout_height="fill_parent"
??? />
</LinearLayout>
//WebJavaScript.java
package com.hl;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class WebJavaScript extends Activity {
?private EditText txt;
?private WebView wv;
?private Button btn;
?private Handler h = new Handler();
???
??? @Override
??? public void onCreate(Bundle savedInstanceState) {
??????? super.onCreate(savedInstanceState);
??????? setContentView(R.layout.main);
??????? txt = (EditText) findViewById(R.id.txt);
??????? wv = (WebView) findViewById(R.id.wv);
??????? btn = (Button) findViewById(R.id.btn);
???????
??????? WebSettings webSettings = wv.getSettings();
???????
??????? webSettings.setJavaScriptEnabled(true);
??????? webSettings.setSaveFormData(false);
??????? webSettings.setSavePassword(false);
??????? webSettings.setSupportZoom(false);
???????
??????? wv.addJavascriptInterface(new runJavaScript(), "myjs");
??????? //myjs是自己定义的，供javascript访问的接口
??????? String url = "file:///android_asset/android.html
";
??????? wv.loadUrl(url);
???????
??????? btn.setOnClickListener(new OnClickListener() {
???@Override
???public void onClick(View v) {
????//调用javascript的函数get4Android(str)
????wv.loadUrl("javascript:get4Android('"+ txt.getText().toString() + "')");?
???}
??});
??? }
??? //The Java object that is bound runs in another thread and not in the thread that it was constructed in.文档的一句话！
??? final class runJavaScript{//这个Java 对象是绑定在另一个线程里的，
????? public void runOnAndroidJavaScript(final String str){
??? ?? h.post(new Runnable(){
????@Override
????public void run() {//这里应该特别注意的
?????TextView show = (TextView) findViewById(R.id.show);
?????? ?? show.setText("This is a message from javascript:"+str);?
????}
????
???});
????? }
??? }
}
//放在assets文件夹的html文件，android.html
<!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile 1.0//EN" "http://www.wapforum.org/DTD/xhtml-mobile10.dtd
">
<html xmlns="http://www.w3.org/1999/xhtml
">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script language="javascript" type="text/javascript">
function get4Android(str){
?document.getElementById("show").innerHTML="This is a message from android:"+str;
?}
function send2Android(){
?var str = document.get
