利用js与java交互

为了方便网页和应用的交互，安卓系统WebView提供JavaScript网页脚本调用Java类方法的机制。只要调用addJavascriptInterface方法即可映射一个Java对象到JavaScript对象上。

MainActivity.java代码：

package com.apple.browser;



import android.annotation.SuppressLint;

import android.app.Activity;

import android.os.Bundle;

import android.view.Menu;

import android.webkit.WebSettings;

import android.webkit.WebView;

import android.widget.Toast;



public class MainActivity extends Activity {



	private WebView webView;

	private Activity activity;



	@SuppressLint("SetJavaScriptEnabled")

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);



		activity = this;



		webView = (WebView) findViewById(R.id.webview);

		webView.loadUrl("file:///android_asset/index.html");



		final WebSettings settings = webView.getSettings();

		settings.setJavaScriptCanOpenWindowsAutomatically(true);

		settings.setJavaScriptEnabled(true);

		settings.setSupportZoom(true);



		webView.addJavascriptInterface(new JSInvokeClass(), "js2java");

	}



	public final class JSInvokeClass {

		public void back() {

			// activity.finish();

			Toast.makeText(activity, "通过js调用的Java方法", Toast.LENGTH_SHORT).show();

		}

	}

}

 
HTML中代码：

<input type=button name=smt value='invoke java' onclick="javascript:window.js2java.back();">

 XML布局代码：
                       略