• iOS socket


    在CFSocket中,TCP连接的创建为

    csocket = CFSocketCreate(

                                             kCFAllocatorDefault,

                                             PF_INET,

                                            SOCK_STREAM,

                                            IPPROTO_TCP,

                                             kCFSocketReadCallBack,

                                            TCPServerConnectCallBack,

                                            &ctx);

                                       。。。。

    sError = CFSocketConnectToAddress(csocket,address, -1);

    这里在连接成功时回调用TCPServerConnectCallBack方法,

    那么如果需要UDP传输数据的话,

    csocket = CFSocketCreate(

                                             kCFAllocatorDefault,

                                             PF_INET,

                                            SOCK_DGRAM,

                                             IPPROTO_UDP,

                                            kCFSocketConnectCallBack,

                                            TCPServerConnectCallBack,

                                            &ctx);

    1.TCP是有连接的,可靠的、可控制的、无边界的socket通信。

    2.UDP是无连接的、不可靠的 数据报通信。但是效率高。

    所以在TCP中要用回调来确定是否连接成功,而原生的socket连接成功是通过serveice发回信息来确定。UDP无连接,所以不需要回调,而不管是否发送成功。

    第三部分、完整的使用方法

    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CallbackTypes

    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(CFSocketRefsocket, 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(CFSocketRefsocket, 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, CFStreamEventTypeeventType, 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

    }

     
     
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  • 原文地址:https://www.cnblogs.com/wudan7/p/3912250.html
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