Android判断是否有网络连接

1. 添加相应的权限

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

2. 判断方法

public boolean isNetworkAvailable() {     
   Context context = getApplicationContext();     
   ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);     
   if (connectivity == null) {     
	   Toast.makeText(getBaseContext(), "zm zm zm zm zm zm ",	Toast.LENGTH_LONG).show();     
   } else {     
      NetworkInfo[] info = connectivity.getAllNetworkInfo();     
      if (info != null) {     
         for (int i = 0; i < info.length; i++) {     
            if (info[i].getState() == NetworkInfo.State.CONNECTED) {     
               return true;     
            }     
         }     
      }     
   }     
   return false;     
}