Android - 判断网络状态

Android手机同时支持WIFI和3G, 判断网络连接, 判断网络类型(WIFI或3G).

权限:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

判断网络连接

    /**
     * 判断网络是否可用, 在使用网络请求是预先使用此方法进行检查, 以节省资源.
     *
     * @return 可用状态
     */
    public static boolean isNetAvailable() {
        Context context = App.getAppContext();
        ConnectivityManager manager = (ConnectivityManager)
             context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = manager.getActiveNetworkInfo();
        return (info != null && info.isAvailable() && info.isConnected());
    }

判断网络类型

ConnectivityManager conMan = (ConnectivityManager) 
    context.getSystemService(Context.CONNECTIVITY_SERVICE);

// 3G
State mobile = conMan.getNetworkInfo(0).getState();

// WIFI
State wifi = conMan.getNetworkInfo(1).getState();

if (mobile == NetworkInfo.State.CONNECTED 
    || mobile == NetworkInfo.State.CONNECTING) {
    // TODO: in mobile do something
} else if (wifi == NetworkInfo.State.CONNECTED 
            || wifi == NetworkInfo.State.CONNECTING) {
    // TODO: in wifi do something
}

更加精细的网络类型:
TelephonyManager#getNetworkType or NetworkInfo#getSubtypeName