网络判断

import android.content.Context;import android.net.ConnectivityManager;import android.net.NetworkInfo;public class NetWorkUtils {    //判断网络是否连接    public static boolean isNetWorkAvailable(Context context) {        //网络连接管理器        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);        //网络信息        NetworkInfo info = connectivityManager.getActiveNetworkInfo();        if (info != null) {            return true;        }        return false;    }}//使用
boolean b = NetWorkUtils.isNetWorkAvailable(this);if (b){    Toast.makeText(this, "有网", Toast.LENGTH_SHORT).show();}else {    Toast.makeText(this, "没网", Toast.LENGTH_SHORT).show();}