Android编程获取网络连接.pdfVIP

Android 编程获取网络连接状态 (3G/Wifi) 及调用网络配置界面 获取网络连接状态 随着 3G 和 Wifi 的推广，越来越多的 Android 应用程序需要调用网络资源，检测网络连接状态 也就成为网络应用程序所必备的功能。 Android 平台提供了 ConnectivityManager 类，用于网络连接状态的检测。 Android 开发文档这样描述 ConnectivityManager 的作用： Class that answers queries about the state of network connectivity. It also notifies applications when network connectivity changes. Get an instance of this class by calling Context.getSystemService(Context.CONNECTIVITY_SERVICE ) . The primary responsibilities of this class are to: 1. Monitor network connections (Wi-Fi, GPRS, UMTS, etc.) 2. Send broadcast intents when network connectivity changes 3. Attem pt to fail over to another network when connectivity to a network is lost 4. Provide an API that allows applications to query the coarse-grained or fine-grained state of the available networks 下面这个简单的例子 checkNetworkInfo() 说明了如何编程获取 Android 手机的当前网络状 态 private void checkNetworkInfo() { ConnectivityManager conMan = (ConnectivityManager) getSystemService(Co ntext.CONNECTIVITY_SERVICE); //mobile 3G Data Network State mobile = conMan.getNetworkInfo(ConnectivityManager.TYPE_MOBILE). getState(); txt3G.setText(mobile.toString()); // 显示 3G 网络连接状态 //wifi State wifi = conMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getS tate(); txtWifi.setText(wifi.toString()); // 显示 wifi 连接状态 } 注 : 根据 Android 的安全机制，在使用 ConnectivityManager 时，必须在 AndroidManifest.xml 中添加 uses-permission android:name=android.permission.ACCESS_NE