VC++ 用Socket怎样编持续接收数据的程序

你这种是用的阻塞模式，就是 Accept和Receive 都会卡住不动，直到有新连接或者有新数据。

实际使用场景中，阻塞模式，一个线程专门Accept 有新的连接之后，为每一个连接再创建一个线程来处理 Receive，也就是对于服务器来说，假设当前有10个工作的连接，那么至少需要11个线程。
你只需要开几个专门的线程来负责接受连接和接收数据就可以了。
这种阻塞模式不适合大并发量的网络程序，测试小程序没问题，大并发量时需要使用非阻塞模式，比如一般常用的select模式
百度 “select模型” 就可以搜到。

VC++ 用Socket持续接收数据的程序举例如下：
while(1) { //client receiving code
if ((numbytes = recv(sockfd, buf, MAXDATASIZE, 0)) == -1)
perror("recv");
}
buf[numbytes] = '\0';
printf("numbytes is %d\n", numbytes);
printf("client: received '%s'\n", buf);
}
以下是输出：
numbytes is 0
client: received '12345'
numbytes is 0
client: received '6'
numbytes is 0
client: received ''
numbytes is 0
client: received ''
numbytes is 0
client: received ''
numbytes is 0
client: received ''
numbytes is 0
client: received ''
numbytes is 0
client: received ''
numbytes is 0
client: received ''
numbytes is 0
client: received ''