首先在AndroidManifest.xml中添加与连接网络相关的权限: 判断联网的代码如下:ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo(); if(networkInfo == null !networkInfo.isAvailable()) { //当前有可用网络 } else { //当前无可用网络 }