android4.4 webview調用javascript出現Uncaught ReferenceError: is not define或者has no method，webviewuncaught
這幾天用Nexus5 4.4.4系統做一個簡單的手機裝置號擷取，然後調用javascript顯示在網頁裡的功能，以前做過n多類似的程式，結果程式一運行啥問題都出來了，呵呵
[INFO:CONSOLE(1)] "Uncaught ReferenceError: is not define
I/chromium(490): [INFO:CONSOLE(1)] "Uncaught SyntaxError: Unexpected token ILLEG
[Android] Web Console: Uncaught TypeError: Object [object Object] has no method 'xxx'
總結來看就是上述問題，先看代碼吧
demo.html
<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title>無標題文檔</title></head> <script> function getDeviceID(info){alert("裝置號："+info); //document.write("裝置號："+info); return "good."; } </script> <body> <a href="http://www.baidu.com" target="_blank"> href="http://www.baidu.com" 開啟baidu </a> <br/> <br/> <a href="http://www.baidu.com/closeappwin" target="_blank"> href="http://www.baidu.com/closeappwin" 關閉瀏覽器closeappwin </a> <br/> <br/> <a href="new://www.sohu.com/" target="_blank"> href="new://www.sohu.com/" 在當前瀏覽器開啟一個子瀏覽器new subwindow </a> <br/> <br/> </body> </html>
看看我的android 代碼如下：
private void loadUrl(){String key="";String androidID="";try{androidID = Secure.getString(getContentResolver(),Secure.ANDROID_ID);Log.d(TAG, "androidID:"+androidID);}catch(Exception e){Log.e(TAG, "");}finally{String script=String.format("javascript:getDeviceID('"+androidID+"')");mWebview.evaluateJavascript(script, new ValueCallback<String>() { @Override public void onReceiveValue(String value) { Log.d(TAG, "onReceiveValue value=" + value); if(value!=null){ flag_get_deviceid=true; } }});//mWebview.loadUrl("javascript:getDeviceID('maomao')");}}
基本上就出現上面的錯誤了，我想是不是4.4的系統在寫法上跟低版本不一樣，還是用了2種調用方式：
mWebview.evaluateJavascript
mWebview.loadUrl("javascript:getDeviceID('maomao')");
那最後的判斷就是一種可能： 調用getDeviceID 方法的時候，js沒有載入完畢。
解決辦法：
private class WebViewClientDemo extends WebViewClient {@Overridepublic boolean shouldOverrideUrlLoading(WebView view, String url) {Log.d(TAG, " url:"+url);view.loadUrl(url);// 當開啟新連結時，使用當前的 WebView，不會使用系統其他瀏覽器return true;}@Override public void onPageFinished(WebView view, String url) { super.onPageFinished(view, url); //在這裡執行你想調用的js函數 if(!flag_get_deviceid){ loadUrl(); } }}
最後順便提一下 webview.evaluateJavascript的好處，這個方法，可以把js函數的return結果擷取到：
mWebview.evaluateJavascript(script, new ValueCallback<String>() { @Override public void onReceiveValue(String value) { Log.d(TAG, "onReceiveValue value=" + value); if(value!=null){ flag_get_deviceid=true; } }});
mWebView.setWebChromeClient(new MyWebChromeClient()); mWebView.addJavascriptInterface(new Object(){ /** * This is not called on the UI thread. Post a runnable to invoke * loadUrl on the UI thread. */ public void clickOnAndroid() { mHandler.post(new Runnable() { public void run() { mWebView.loadUrl("javascript:wave()"); } }); } }, "demo"); 同理，在html中必須有一個名為demo的對象調用clickOnAndroid()方法。 /** * Provides a hook for calling "alert" from javascript. Useful for * debugging your javascript. */ final class MyWebChromeClient extends WebChromeClient { @Override public boolean onJsAlert(WebView view, String url, String message, JsResult result) { result.confirm(); return super.onJsAlert(view, url, message, result); } }
android開發中WebView載入了帶有flash的html網頁，為何在電腦上有效flash調用javascript這時失效
webview 需要設定enablejavascript(true)即允許webview執行javascript
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