Android 通过WebView和js的交互
Android中可以通过WebView来实现和js的交互,在程序中调用js代码,只需要将WebView控件的支持js的属性设置为true
Android(Java)与 JavaScript(HTML)交互有四种情况:
1)Android(Java)调用HTML中js代码
2)Android(Java)调用HTML中js代码(带参数)
3)HTML中js调用Android(Java)代码
4)HTML中js调用Android(Java)代码(带参数)
下面示例总结这四种情况,直接上干货:
1.Android-Java
private void showWebView() { // webView与js交互代码try {mWebView = new WebView(this);setContentView(mWebView);mWebView.requestFocus();mWebView.setWebChromeClient(new WebChromeClient() {@Overridepublic void onProgressChanged(WebView view, int progress) {JSAndroidActivity.this.setTitle("Loading...");JSAndroidActivity.this.setProgress(progress);if (progress >= 80) {JSAndroidActivity.this.setTitle("JsAndroid Test");}}});mWebView.setOnKeyListener(new View.OnKeyListener() { // webview can// go back@Overridepublic boolean onKey(View v, int keyCode, KeyEvent event) {if (keyCode == KeyEvent.KEYCODE_BACK&& mWebView.canGoBack()) {mWebView.goBack();return true;}return false;}});WebSettings webSettings = mWebView.getSettings();webSettings.setJavaScriptEnabled(true);webSettings.setDefaultTextEncodingName("utf-8");mWebView.addJavascriptInterface(getHtmlObject(), "jsObj");mWebView.loadUrl("http://192.168.1.121:8080/jsandroid/index.html");} catch (Exception e) {e.printStackTrace();}}private Object getHtmlObject() {Object insertObj = new Object() {public String HtmlcallJava() {return "Html call Java";}public String HtmlcallJava2(final String param) {return "Html call Java : " + param;}public void JavacallHtml() {runOnUiThread(new Runnable() {@Overridepublic void run() {mWebView.loadUrl("javascript: showFromHtml()");Toast.makeText(JSAndroidActivity.this, "clickBtn",Toast.LENGTH_SHORT).show();}});}public void JavacallHtml2() {runOnUiThread(new Runnable() {@Overridepublic void run() {mWebView.loadUrl("javascript: showFromHtml2('IT-homer blog')");Toast.makeText(JSAndroidActivity.this, "clickBtn2",Toast.LENGTH_SHORT).show();}});}};return insertObj;}
2.js-HTML
<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta http-equiv="Expires" content="0"> <meta http-equiv="Pragma" content="no-cache"> <meta http-equiv="Cache-Control" content="no-store,no-cache"> <meta name="Handheldfriendly" content="true"> <meta name="viewport" content="width=100%; initial-scale=1.0; user-scalable=yes"> <meta name="robots" content="all"> <meta name="keywords" contect="doodle, mobile, doodlemobile, game, games"> <meta name="description" content="Make People's Mobile Life More Connected Through Games."> <title> jsandroid_test </title> <script type="text/javascript" language="javascript"> function showHtmlcallJava(){ var str = window.jsObj.HtmlcallJava(); alert(str); } function showHtmlcallJava2(){ var str = window.jsObj.HtmlcallJava2("IT-homer blog"); alert(str); } function showFromHtml(){ document.getElementById("id_input").value = "Java call Html"; } function showFromHtml2( param ){ document.getElementById("id_input2").value = "Java call Html : " + param; } </script> </head> <body> hello IT-homer<br> <br> <br> <form> <input type="button" value="HtmlcallJava" onclick="showHtmlcallJava()"><br> <input type="button" value="HtmlcallJava2" onclick="showHtmlcallJava2()"><br> <br> <br> <br> <input id="id_input" style="width: 90%" type="text" value="null"><br> <input type="button" value="JavacallHtml" onclick="window.jsObj.JavacallHtml()"><br> <br> <br> <input id="id_input2" style="width: 90%" type="text" value="null"><br> <input type="button" value="JavacallHtml2" onclick="window.jsObj.JavacallHtml2()"> </form> </body></html>
3.运行结果
4.代码解析
1) 允许Android执行js脚本设置
Android(Java)与js(HTML)交互的接口函数是: mWebView.addJavascriptInterface(getHtmlObject(),"jsObj"); // jsObj 为桥连对象
Android容许执行js脚本需要设置:webSettings.setJavaScriptEnabled(true);
2) js(HTML)访问Android(Java)代码
js(HTML)访问Android(Java)端代码是通过jsObj对象实现的,调用jsObj对象中的函数,如:window.jsObj.HtmlcallJava()
3) Android(Java)访问js(HTML)代码
Android(Java)访问js(HTML)端代码是通过loadUrl函数实现的,访问格式如:mWebView.loadUrl("javascript:showFromHtml()");
说明:
1) Android访问url网址,需在AndroidManifest.xml文件,配置容许访问网络的权限:
<uses-permissionandroid:name="android.permission.INTERNET" />
2) Android(Java)调用js(HTML)时,使用的mWebView.loadUrl("javascript:showFromHtml()");函数需在UI线程运行,因为mWebView为UI控件
public void JavacallHtml() {runOnUiThread(new Runnable() {@Overridepublic void run() {mWebView.loadUrl("javascript: showFromHtml()");Toast.makeText(JSAndroidActivity.this, "clickBtn",Toast.LENGTH_SHORT).show();}});}
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