android判斷網絡鏈接狀態-ConnectivityManager

android.net.ConnectivityManager主要用於管理與網絡鏈接相關的操做。
須要訪問網絡，首先須要添加權限

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

示例代碼以下：

   protected void testNetwork(){
    ConnectivityManager cm = (ConnectivityManager) this.getSystemService(CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = cm.getActiveNetworkInfo();

     if(networkInfo.isAvailable()){
      Log.i(TAG, "network available");
    } else{
      Log.i(TAG , "network not available");
    }
    
     if(State.CONNECTED == cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState()){
      Log.i(TAG , "gprs is connected");
    }
    
     if(State.CONNECTED == cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState()){
      Log.i(TAG, "wifi is connected");     }   }