客户端：
导入头文件：
#import <sys/socket.h>
#import <netinet/in.h>
#import <arpa/inet.h>
#import <unistd.h>
1. 创建连接
CFSocketContext sockContext = {0, // 结构体的版本，必须为0
self,
// 一个任意指针的数据，可以用在创建时CFSocket对象相关联。这个指针被传递给所有的上下文中定义的回调。
NULL, // 一个定义在上面指针中的retain的回调， 可以为NULL
NULL, NULL};
CFSocketRef _socket = (kCFAllocatorDefault, // 为新对象分配内存，可以为nil
PF_INET, // 协议族，如果为0或者负数，则默认为PF_INET
SOCK_STREAM, // 套接字类型，如果协议族为PF_INET,则它会默认为SOCK_STREAM
IPPROTO_TCP, // 套接字协议，如果协议族是PF_INET且协议是0或者负数，它会默认为IPPROTO_TCP
kCFSocketConnectCallBack, // 触发回调函数的socket消息类型，具体见Callback Types
TCPServerConnectCallBack, // 上面情况下触发的回调函数
&sockContext // 一个持有CFSocket结构信息的对象，可以为nil
);
if (_socket != nil) {
struct sockaddr_in addr4; // IPV4
memset(&addr4, 0, sizeof(addr4));
addr4.sin_len = sizeof(addr4);
addr4.sin_family = AF_INET;
addr4.sin_port = htons(8888);
addr4.sin_addr.s_addr = inet_addr([strAddress UTF8String]); // 把字符串的地址转换为机器可识别的网络地址
// 把sockaddr_in结构体中的地址转换为Data
CFDataRef address = CFDataCreate(kCFAllocatorDefault, (UInt8 *)&addr4, sizeof(addr4));
CFSocketConnectToAddress(_socket, // 连接的socket
address, // CFDataRef类型的包含上面socket的远程地址的对象
-1 // 连接超时时间，如果为负，则不尝试连接，而是把连接放在后台进行，如果_socket消息类型为kCFSocketConnectCallBack，将会在连接成功或失败的时候在后台触发回调函数
);
CFRunLoopRef cRunRef = CFRunLoopGetCurrent(); // 获取当前线程的循环
// 创建一个循环，但并没有真正加如到循环中，需要调用CFRunLoopAddSource
CFRunLoopSourceRef sourceRef = CFSocketCreateRunLoopSource(kCFAllocatorDefault, _socket, 0);
CFRunLoopAddSource(cRunRef, // 运行循环
sourceRef, // 增加的运行循环源, 它会被retain一次
kCFRunLoopCommonModes // 增加的运行循环源的模式
);
CFRelease(courceRef);
}
2. 设置回调函数
// socket回调函数的格式： static void TCPServerConnectCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) ｛ if (data != NULL) { // 当socket为kCFSocketConnectCallBack时，失败时回调失败会返回一个错误代码指针，其他情况返回NULL NSLog(@"连接失败"); return; } TCPClient *client = (TCPClient *)info; // 读取接收的数据 [info performSlectorInBackground:@selector(readStream) withObject:nil]; ｝ 3. 接收发送数据 // 读取接收的数据 - (void)readStream { char buffer[1024]; NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; while (recv(CFSocketGetNative(_socket), //与本机关联的Socket 如果已经失效返回－1:INVALID_SOCKET buffer, sizeof(buffer), 0)) { NSLog(@"%@", [NSString stringWithUTF8String:buffer]); } } // 发送数据 - (void)sendMessage { NSString *stringTosend = @"你好"; char *data = [stringTosend UTF8String]; send(SFSocketGetNative(_socket), data, strlen(data) + 1, 0); } 服务器端： CFSockteRef _socket; CFWriteStreamRef outputStream = NULL; int setupSocket() { _socket = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_STREAM, IPPROTO_TCP, kCFSocketAcceptCallBack, TCPServerAcceptCallBack, NULL); if (NULL == _socket) { NSLog(@"Cannot create socket!"); return 0; } int optval = 1; setsockopt(CFSocketGetNative(_socket), SOL_SOCKET, SO_REUSEADDR, // 允许重用本地地址和端口 (void *)&optval, sizeof(optval)); struct sockaddr_in addr4; memset(&addr4, 0, sizeof(addr4)); addr4.sin_len = sizeof(addr4); addr4.sin_family = AF_INET; addr4.sin_port = htons(port); addr4.sin_addr.s_addr = htonl(INADDR_ANY); CFDataRef address = CFDataCreate(kCFAllocatorDefault, (UInt8 *)&addr4, sizeof(addr4)); if (kCFSocketSuccess != CFSocketSetAddress(_socket, address)) { NSLog(@"Bind to address failed!"); if (_socket) CFRelease(_socket); _socket = NULL; return 0; } CFRunLoopRef cfRunLoop = CFRunLoopGetCurrent(); CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, _socket, 0); CFRunLoopAddSource(cfRunLoop, source, kCFRunLoopCommonModes); CFRelease(source); return 1; } // socket回调函数，同客户端 void TCPServerAcceptCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) { if (kCFSocketAcceptCallBack == type) { // 本地套接字句柄 CFSocketNativeHandle nativeSocketHandle = *(CFSocketNativeHandle *)data; uint8_t name[SOCK_MAXADDRLEN]; socklen_t nameLen = sizeof(name); if (0 != getpeername(nativeSocketHandle, (struct sockaddr *)name, &nameLen)) { NSLog(@"error"); exit(1); } NSLog(@"%@ connected.", inet_ntoa( ((struct sockaddr_in *)name)->sin_addr )): CFReadStreamRef iStream; CFWriteStreamRef oStream; // 创建一个可读写的socket连接 CFStreamCreatePairWithSocket(kCFAllocatorDefault, nativeSocketHandle, &iStream, &oStream); if (iStream && oStream) { CFStreamClientContext streamContext = {0, NULL, NULL, NULL}; if (!CFReadStreamSetClient(iStream, kCFStreamEventHasBytesAvaiable, readStream, // 回调函数，当有可读的数据时调用 &streamContext)){ exit(1); } if (!CFReadStreamSetClient(iStream, kCFStreamEventCanAcceptBytes, writeStream, &streamContext)){ exit(1); } CFReadStreamScheduleWithRunLoop(iStream, CFRunLoopGetCurrent(), kCFRunLoopCommomModes); CFWriteStreamScheduleWithRunLoop(wStream, CFRunLoopGetCurrent(), kCFRunLoopCommomModes); CFReadStreamOpen(iStream); CFWriteStreamOpen(wStream); } else { close(nativeSocketHandle); } } } // 读取数据 void readStream(CFReadStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo) { UInt8 buff[255]; CFReadStreamRead(stream, buff, 255); printf("received: %s", buff); } void writeStream (CFWriteStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo) { outputStream = stream; } main { char *str = "nihao"; if (outputStream != NULL) { CFWriteStreamWrite(outputStream, str, strlen(line) + 1); } else { NSLog(@"Cannot send data!"); } } // 开辟一个线程线程函数中 void runLoopInThread() { int res = setupSocket(); if (!res) { exit(1); } CFRunLoopRun(); // 运行当前线程的CFRunLoop对象 }