socket编程（转）

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
 }