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Android与js交互实例

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(){ 				@Override 				public 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 				@Override 				public 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() { 					@Override 					public void run() { 						mWebView.loadUrl("javascript: showFromHtml()"); 						Toast.makeText(JSAndroidActivity.this, "clickBtn", Toast.LENGTH_SHORT).show(); 					} 				}); 			} 			 			public void JavacallHtml2(){ 				runOnUiThread(new Runnable() { 					@Override 					public void run() { 						mWebView.loadUrl("javascript: showFromHtml2('IT-homer blog')"); 						Toast.makeText(JSAndroidActivity.this, "clickBtn2", Toast.LENGTH_SHORT).show(); 					} 				}); 			} 		}; 		 		return insertObj; 	}

2) js(HTML)

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <!-- saved from url=(0032)http://localhost:8080/jsandroid/ --> <html xmlns="http://www.w3.org/1999/xhtml"><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>  <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()" />  </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-permission android: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() { 					@Override 					public void run() { 						mWebView.loadUrl("javascript: showFromHtml()"); 						Toast.makeText(JSAndroidActivity.this, "clickBtn", Toast.LENGTH_SHORT).show(); 					} 				}); 			}

源码下载

参考推荐:

Android中webview和js之间的交互

Android中 Js 扩展及交互