1、Android 課程講義,智能手機開發(fā),6、網(wǎng)絡連接,智能手機開發(fā),2010.06.,浙江大學計算機學院,3,網(wǎng)絡訪問,使用網(wǎng)絡，應該有相應使用允許。 文件AndroidManifest添加：, ,2010.06.,浙江大學計算機學院,4,以Get請求從Internet獲取數(shù)據(jù),建立HttpClient，選擇post或get請求服務器而獲得網(wǎng)頁數(shù)據(jù)。,HttpClient client = new DefaultHttpClient(); HttpGet get = new HttpGet(url); HttpResponse response = client.execute(get); H

2、ttpEntity entity = response.getEntity(); /嘗試讀取entity的長度，返回-1表示長度未知 long length = entity.getContentLength(); InputStream is = entity.getContent();,2010.06.,浙江大學計算機學院,5,從Internet獲取數(shù)據(jù),利用HttpURLConnection對象,我們可以從網(wǎng)絡中獲取網(wǎng)頁數(shù)據(jù)。,URL url = new URL(); HttpURLConnection conn = (HttpURLConnection) url.openConnect

3、ion(); conn.setConnectTimeout(6* 1000);/設置連接超時 if (conn.getResponseCode() != 200) throw new RuntimeException(請求url失敗); InputStream is = conn.getInputStream();/得到網(wǎng)絡返回的輸入流 String result = readData(is, GBK); conn.disconnect(); System.out.println(result);,2010.06.,浙江大學計算機學院,6,從Internet獲取數(shù)據(jù),利用HttpURLConn

4、ection對象,我們可以從網(wǎng)絡中獲取文件數(shù)據(jù)。,URL url = new URL( HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setConnectTimeout(6* 1000); if (conn.getResponseCode() != 200) throw new RuntimeException(請求url失敗); InputStream is = conn.getInputStream(); readAsFile(is, ImgAndroid.jpg);,2010.06.,浙江大學計算機學院,7,廣播sendBroadcast(),Intent之間傳遞數(shù)據(jù) 廣播Intent通過調(diào)用發(fā)送信息 Context.sendBroadcast() Context.sendOrderedBroadcast() Context.sendStickyBroadcast() 通常一個廣播Intent可以被訂閱了此Intent的多個廣播接收者所接收。,2010.06.,浙江大學計算機學院,8,廣播接收者BroadcastReceiver,第一步：繼承BroadcastReceiver，并重寫onRec