Android为TV端助力之Webview与JS双向交互

1package com.hhzt.iptv.adservice;import android.app.Activity;import android.graphics.Bitmap;import android.os.Build;import android.os.Bundle;import android.util.Log;import android.view.KeyEvent;import android.view.ViewGroup;import android.webkit.ConsoleMessage;import android.webkit.ValueCallback;import android.webkit.WebChromeClient;import android.webkit.WebResourceError;import android.webkit.WebResourceRequest;import android.webkit.WebSettings;import android.webkit.WebView;import android.webkit.WebViewClient;import android.widget.TextView;/** * Created by Administrator on 2019-04-16. */public class AdActivity extends Activity {    private WebView mWebView;    private WebSettings mWebSetting;    TextView beginLoading,endLoading,loading,mtitle;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.ad);        mWebView =  (WebView)findViewById(R.id.webView1);        beginLoading = (TextView) findViewById(R.id.text_beginLoading);        endLoading = (TextView) findViewById(R.id.text_endLoading);        loading = (TextView) findViewById(R.id.text_Loading);        mtitle = (TextView) findViewById(R.id.title);        mWebSetting =  mWebView.getSettings();        mWebSetting.setJavaScriptEnabled(true);        /**         * 传一个Android对象给JS,JS拿到对象以后就可以调用你传递的对象里面的方法         */        mWebView.addJavascriptInterface(new MyWeb(),"test");//AndroidtoJS类对象映射到js的test对象        mWebView.loadUrl("file:///android_asset/index.html");        /**         * （2）　WebViewClient类（主要作用是：处理各种通知 & 请求事件）         */        mWebView.setWebViewClient(new WebViewClient(){            @Override            public boolean shouldOverrideUrlLoading(WebView view, String url) {                //使得打开网页时不调用系统浏览器， 而是在本WebView中显示                view.loadUrl(url);                return super.shouldOverrideUrlLoading(view, url);            }            @Override            public void onPageStarted(WebView view, String url, Bitmap favicon) {                //设定加载开始的操作             //   super.onPageStarted(view, url, favicon);                System.out.println("开始加载了");                beginLoading.setText("开始加载了");            }            @Override            public void onPageFinished(WebView view, String url) {                //设定加载结束的操作              //  super.onPageFinished(view, url);                endLoading.setText("结束加载了");                // Android版本变量                final int version = Build.VERSION.SDK_INT;                /**                 * 因为该方法在 Android 4.4 版本才可使用，所以使用时需进行版本判断                 * android 调用JS代码。需要在webview也没加载完成时调用，否则无效                 */                if (version < 18) {                    mWebView.loadUrl("javascript:callAndroid()");                } else {                    mWebView.evaluateJavascript("javascript:callAndroid()", new ValueCallback<String>() {                        @Override                        public void onReceiveValue(String value) {                            //此处为 js 返回的结果                            Log.i("TAG","onReceiveValue:"+value);                        }                    });                }            }            @Override            public void onLoadResource(WebView view, String url) {                //设定加载资源的操作                super.onLoadResource(view, url);            }            @Override            public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {            }            @Override            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {                //该方法传回了错误码，根据错误类型可以进行不同的错误分类处理                Log.i("TAG","onReceivedError:"+errorCode);                super.onReceivedError(view, errorCode, description, failingUrl);            }        });        /**         * （3）　WebChromeClient类( 作用：辅助 WebView 处理 Javascript 的对话框,网站图标,网站标题等等。)         */        mWebView.setWebChromeClient(new WebChromeClient(){            @Override            public void onProgressChanged(WebView view, int newProgress) {                Log.i("TAG","onProgressChanged:"+newProgress);                if (newProgress < 100) {                    String progress = newProgress + "%";                    loading.setText(progress);                } else if (newProgress == 100) {                    String progress = newProgress + "%";                    loading.setText(progress);                }            }            //获取网站标题            @Override            public void onReceivedTitle(WebView view, String title) {//                super.onReceivedTitle(view, title);                System.out.println("标题在这里");                mtitle.setText(title);            }            //获取网站logo            @Override            public void onReceivedIcon(WebView view, Bitmap icon) {                super.onReceivedIcon(view, icon);            }            @Override            public boolean onConsoleMessage(ConsoleMessage consoleMessage) {                Log.i("TAG","onConsoleMessage:"+consoleMessage.message()+ "-- from line "+consoleMessage.lineNumber()+" of "+consoleMessage.sourceId());               //这个方法返回Webview加载JS时的日志信息                return super.onConsoleMessage(consoleMessage);            }        });    }    @Override    protected void onResume() {        super.onResume();    }    //销毁Webview    @Override    protected void onDestroy() {        if (mWebView != null) {     //       mWebView.loadDataWithBaseURL(null, "", "text/html", "utf-8", null);            mWebView.clearHistory();            ((ViewGroup) mWebView.getParent()).removeView(mWebView);            mWebView.destroy();            mWebView = null;        }        super.onDestroy();    }    //点击返回上一页面而不是退出浏览器    @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {        if (keyCode == KeyEvent.KEYCODE_BACK && mWebView.canGoBack()) {            mWebView.goBack();            return true;        }        return super.onKeyDown(keyCode, event);    }}index.hdml界面
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3<!DOCTYPE html><html><head>    <meta charset="utf-8">    <title>Carson</title></head><body>//点击按钮则调用callAndroid函数<button onclick="callAndroid()"></button></body><script>         function callAndroid(){        // 由于对象映射，所以调用test对象等于调用Android映射的对象,注意此处不能定义test，如果定义的那就是一个新的对象，将会提示无法找到hello方法            test.hello("js调用了android中的hello方法");         }</script></html>
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5友情提示：修改index.html文件时，记得clean project一下，因为你运行时间AS编译器不会去编译assets里面的文件，或者在项目的build.gradle加上
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7sourceSets {    main {        manifest.srcFile 'src/main/AndroidManifest.xml'        java.srcDirs = ['src/main/java', 'src/main/aidl']        resources.srcDirs = ['src/main/java', 'src/main/aidl']        aidl.srcDirs = ['src/main/aidl']        res.srcDirs = ['src/main/res']        assets.srcDirs = ['src/main/assets']    }}