懒人理解：socket通信
1）服务端：我就管收，收到算收不到拉倒，我不管你是谁。
2）客户端：我就管发，成功与否我不管，我管你你谁。
简易代码：
1）服务端：
- (void)udpServer {
int serverSockerId = -1;
ssize_t len = -1;
socklen_t addrlen;
char buff[1024];
char k[1024];
struct sockaddr_in ser_addr;
// 创建socket
serverSockerId = socket(AF_INET, SOCK_DGRAM, 0);
if(serverSockerId < 0) {
// 建立服务套接字 失败
}
addrlen = sizeof(struct sockaddr_in);
bzero(&ser_addr, addrlen);
ser_addr.sin_family = AF_INET;
ser_addr.sin_addr.s_addr = htonl(INADDR_ANY);
// 端口号
ser_addr.sin_port = htons(123456);
// 绑定端口号
if(bind(serverSockerId, (struct sockaddr *)&ser_addr, addrlen) < 0) {
// 服务器连接套接字失败
return;
}
do {
bzero(buff, sizeof(buff));
// 接收客户端的消息
len = recvfrom(serverSockerId, buff, sizeof(buff), 0, (struct sockaddr *)&ser_addr, &addrlen);
// 显示客户端的网络地址
NSLog(@"receive from %s\n", inet_ntoa(ser_addr.sin_addr));
// 显示客户端发来的字符串
NSLog(@"recevce:%s", buff);
// 将接收到的客户端发来的消息，发回客户端
// 将字串返回给client端
sprintf(k, "%s", "Good Morning!");
sendto(serverSockerId, k, len, 0, (struct sockaddr *)&ser_addr, addrlen);
} while (strcmp(buff, "exit") != 0);
NSLog(@"end loop");
// 关闭socket
close(serverSockerId);
}
2）客户端：
- (void)udpClient {
int clientSocketId;
ssize_t len;
socklen_t addrlen;
struct sockaddr_in client_sockaddr;
char buffer[256] = "Hello, server, how are you?";
// 创建Socket
clientSocketId = socket(AF_INET, SOCK_DGRAM, 0);
if(clientSocketId < 0) {
// 创建失败
NSLog(@"creat client socket fail\n");
return;
}
addrlen = sizeof(struct sockaddr_in);
bzero(&client_sockaddr, addrlen);
client_sockaddr.sin_family = AF_INET;
client_sockaddr.sin_addr.s_addr = inet_addr("169.254.8.184");
client_sockaddr.sin_port = htons(150431);
// 循环发100个
int count = 100;
do {
NSLog(@"count = %d",count);
bzero(buffer, sizeof(buffer));
char xy[1024] = "Hello";
xy[5] = count;
sprintf(buffer, "%s%d", "Msg",count);
// 发送消息到服务端
// 注意:UDP是面向无连接的，因此不用调用connect()
// 将字符串传送给server端
len = sendto(clientSocketId, buffer, sizeof(buffer), 0, (struct sockaddr *)&client_sockaddr, addrlen);
if (len > 0) {
NSLog(@"发送成功");
} else {
NSLog(@"发送失败");
}
// 接收来自服务端返回的消息
// 接收server端返回的字符串
bzero(buffer, sizeof(buffer));
// len = recvfrom(clientSocketId, buffer, sizeof(buffer), 0, (struct sockaddr *)&client_sockaddr, &addrlen);
// NSLog(@"receive message from server: %s", buffer);
// NSString *str = [NSString stringWithCString:buffer encoding:NSUTF8StringEncoding];
// NSLog(@"string is %@",str);
count--;
sleep(0.1);
} while (count >= 0);
// 关闭socket
// 由于是面向无连接的，消息发出处就可以了，不用管它收不收得到，发完就可以关闭了
// close(clientSocketId);
}