Android为TV端助力之Webview与JS双向交互

package 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

<!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>

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

sourceSets {
    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']
    }
}