android 调用js，js调用android

Java调用JavaScript

 

1.main.xml

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<?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" 
    > 
    <TextView   
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:text="Welcome to Mr Wei's Blog." 
        /> 
    <WebView 
        android:id="@+id/webview" 
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
    /> 
    <Button 
        android:id="@+id/button" 
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="Change the webview content" 
    /> 
</LinearLayout>

2.demo.html

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<html> 
    <mce:script language="javascript"><!-- 
    
        function fillContent(){ 
            document.getElementById("content").innerHTML =  
                 "This Content is showed by Android invoke Javascript function."; 
        } 
       
// --></mce:script>   
  <body> 
    <p><a onClick="window.demo.startMap()" href="">Start GoogleMap</a></p> 
    <p id="content"></p> 
    <p>A Demo ----Android and Javascript invoke each other.</p> 
    <p>Author:Frankiewei</p> 
  </body> 
</html>

3.WebViewDemo.java

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package com.tutor.webwiewdemo;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.Button;
public class WebViewDemo extends Activity {
    private WebView mWebView;
    private Button mButton;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setupViews();
    }
    //初始化
    private void setupViews() {
        mWebView = (WebView) findViewById(R.id.webview);
        WebSettings mWebSettings = mWebView.getSettings();
        //加上这句话才能使用javascript方法
        mWebSettings.setJavaScriptEnabled(true);
        //增加接口方法,让html页面调用
        mWebView.addJavascriptInterface(new Object() {
            //这里我定义了一个打开地图应用的方法
            public void startMap() {
                Intent mIntent = new Intent();
                ComponentName component = new ComponentName(
                        "com.google.android.apps.maps",
                        "com.google.android.maps.MapsActivity");
                mIntent.setComponent(component);
                startActivity(mIntent);
            }
        }, "demo");
        //加载页面
        mWebView.loadUrl("file:///android_asset/demo.html");
        mButton = (Button) findViewById(R.id.button);
        //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:fillContent()");
            }
        });
    }
}

　　

           

              首界面                                               点击按钮时,html内容改变

 

MainActivity.java

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package com.example.jsdemo;
 
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.webkit.WebSettings;
import android.webkit.WebView;
 
public class MainActivity extends AppCompatActivity {
    private WebView wView;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        wView = (WebView) findViewById(R.id.wView);
        wView.loadUrl("file:///android_asset/demo1.html");
        WebSettings webSettings = wView.getSettings();
        //①设置WebView允许调用js
        webSettings.setJavaScriptEnabled(true);
        webSettings.setDefaultTextEncodingName("UTF-8");
        //②设置支持js调用java
        wView.addJavascriptInterface(new AndroidAndJSInterface(),"Android"");
    }
 
 class AndroidAndJSInterface{
        @JavascriptInterface
        public void showToast(){
            Toast.makeText(MainActivity.this, "我被js调用了", Toast.LENGTH_SHORT).show();
        }
    }
}

注意:解决该WebView.addJavascriptInterface接口不起作用的两种办法

①针对版本改成16

②在JavaScript接口类的方法加上@JavascriptInterface注解

2.JavaScript调用Java对象示例

demo1.html

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<input type="button" value="点击Android被调用" onclick="window.Android.showToast()" />

 

 

　　

posted @ 2019-06-28 11:34  左手编程右手诗  阅读(5673)  评论(0)    收藏  举报