获取网络状态(有网--无网)

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class NetWork {
    public static boolean getNet(Context context){
        boolean a=false;
        ConnectivityManager service = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = service.getActiveNetworkInfo();
        if (networkInfo != null) {
             a = networkInfo.isAvailable();
        }
        return a;
    };
}