135、JS和Android交互范例

时间：2024-09-10 11:36:14

很简单的直接上代码

<uses-permission android:name="android.permission.INTERNET" />
assets/web.html
<html>

<head>

    <meta http-equiv="Content-Type" content="text/html;charset=gb2312">

    <script type="text/javascript">

function javacalljs(){

     document.getElementById("content").innerHTML =

         "<br\>JAVA调用了JS的函数";

}

function javacalljswith(arg){

     document.getElementById("content").innerHTML =

         ("<br\>"+arg);

}
</script>

</head>

<body>

        HTML 内容显示 <br/>

<h1>

    <div id="content">内容显示</div>

</h1>

<br/>

<input type="button" value="点击调用java代码" onclick="window.android.startFunction()"/>

<br/>

<input type="button" value="点击调用java代码并传递参数"

       onclick="window.android.startFunction('http://blog.****.net/Leejizhou')"/>

</body>

</html>
package com.leejz.jsdemo;

import android.support.v7.app.AlertDialog;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.webkit.JavascriptInterface;

import android.webkit.WebView;

import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private WebView contentWebView = null;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        contentWebView = (WebView) findViewById(R.id.webview);
// 启用javascript

        contentWebView.getSettings().setJavaScriptEnabled(true);

        // 从assets目录下面的加载html

        contentWebView.loadUrl("file:///android_asset/web.html");

        contentWebView.addJavascriptInterface(MainActivity.this, "android");

        //无参调用Js点击

        findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {
// 无参数调用  WebView中显示  JAVA调用了JS的函数

                contentWebView.loadUrl("javascript:javacalljs()");

            }

        });

        //有参调用Js点击

        findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {
// 传递参数调用    WebView中显示  www.baidu.com

                contentWebView.loadUrl("javascript:javacalljswith("

                        + "'www.baidu.com'" + ")");

            }

        });

    }

    //由于安全原因 需要加 @JavascriptInterface

    @JavascriptInterface
public void startFunction() {

        runOnUiThread(new Runnable() {

            @Override

            public void run() {

                Toast.makeText(MainActivity.this, "吐司", Toast.LENGTH_SHORT).show();

            }

        });

    }

    @JavascriptInterface
public void startFunction(final String text) {

        runOnUiThread(new Runnable() {

            @Override

            public void run() {

                new AlertDialog.Builder(MainActivity.this).setMessage(text).show();

            }

        });

    }

}

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