IOS上的socket通信
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
1 // socket回调函数的格式：
2 static void TCPServerConnectCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) ｛
3 if (data != NULL) {
4 // 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
5 NSLog(@"连接失败");
6 return;
7 }
8 TCPClient *client = (TCPClient *)info;
9 // 读取接收的数据
10 [info performSlectorInBackground:@selector(readStream) withObject:nil];
11 ｝
12 3. 接收发送数据
13 // 读取接收的数据
14 - (void)readStream {
15 char buffer[1024];
16 NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
17 while (recv(CFSocketGetNative(_socket), //与本机关联的Socket 如果已经失效返回－1:INVALID_SOCKET
18 buffer, sizeof(buffer), 0)) {
19 NSLog(@"%@", [NSString stringWithUTF8String:buffer]);
20 }
21 }
22 // 发送数据
23 - (void)sendMessage {
24 NSString *stringTosend = @"你好";
25 char *data = [stringTosend UTF8String];
26 send(SFSocketGetNative(_socket), data, strlen(data) + 1, 0);
27 }
28 服务器端：
29 CFSockteRef _socket;
30 CFWriteStreamRef outputStream = NULL;
31 int setupSocket() {
32 _socket = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_STREAM, IPPROTO_TCP, kCFSocketAcceptCallBack, TCPServerAcceptCallBack, NULL);
33 if (NULL == _socket) {
34 NSLog(@"Cannot create socket!");
35 return 0;
36 }
37
38 int optval = 1;
39 setsockopt(CFSocketGetNative(_socket), SOL_SOCKET, SO_REUSEADDR, // 允许重用本地地址和端口
40 (void *)&optval, sizeof(optval));
41
42 struct sockaddr_in addr4;
43 memset(&addr4, 0, sizeof(addr4));
44 addr4.sin_len = sizeof(addr4);
45 addr4.sin_family = AF_INET;
46 addr4.sin_port = htons(port);
47 addr4.sin_addr.s_addr = htonl(INADDR_ANY);
48 CFDataRef address = CFDataCreate(kCFAllocatorDefault, (UInt8 *)&addr4, sizeof(addr4));
49
50 if (kCFSocketSuccess != CFSocketSetAddress(_socket, address)) {
51 NSLog(@"Bind to address failed!");
52 if (_socket)
53 CFRelease(_socket);
54 _socket = NULL;
55 return 0;
56 }
57
58 CFRunLoopRef cfRunLoop = CFRunLoopGetCurrent();
59 CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, _socket, 0);
60 CFRunLoopAddSource(cfRunLoop, source, kCFRunLoopCommonModes);
61 CFRelease(source);
62
63 return 1;
64 }
65 // socket回调函数，同客户端
66 void TCPServerAcceptCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) {
67 if (kCFSocketAcceptCallBack == type) {
68 // 本地套接字句柄
69 CFSocketNativeHandle nativeSocketHandle = *(CFSocketNativeHandle *)data;
70 uint8_t name[SOCK_MAXADDRLEN];
71 socklen_t nameLen = sizeof(name);
72 if (0 != getpeername(nativeSocketHandle, (struct sockaddr *)name, &nameLen)) {
73 NSLog(@"error");
74 exit(1);
75 }
76 NSLog(@"%@ connected.", inet_ntoa( ((struct sockaddr_in *)name)->sin_addr )):
77 CFReadStreamRef iStream;
78 CFWriteStreamRef oStream;
79 // 创建一个可读写的socket连接
80 CFStreamCreatePairWithSocket(kCFAllocatorDefault, nativeSocketHandle, &iStream, &oStream);
81 if (iStream && oStream) {
82 CFStreamClientContext streamContext = {0, NULL, NULL, NULL};
83 if (!CFReadStreamSetClient(iStream, kCFStreamEventHasBytesAvaiable,
84 readStream, // 回调函数，当有可读的数据时调用
85 &streamContext)){
86 exit(1);
87 }
88 if (!CFReadStreamSetClient(iStream, kCFStreamEventCanAcceptBytes, writeStream, &streamContext)){
89 exit(1);
90 }
91 CFReadStreamScheduleWithRunLoop(iStream, CFRunLoopGetCurrent(), kCFRunLoopCommomModes);
92 CFWriteStreamScheduleWithRunLoop(wStream, CFRunLoopGetCurrent(), kCFRunLoopCommomModes);
93 CFReadStreamOpen(iStream);
94 CFWriteStreamOpen(wStream);
95 } else {
96 close(nativeSocketHandle);
97 }
98 }
99 }
100 // 读取数据
101 void readStream(CFReadStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo) {
102 UInt8 buff[255];
103 CFReadStreamRead(stream, buff, 255);
104 printf("received: %s", buff);
105 }
106 void writeStream (CFWriteStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo) {
107 outputStream = stream;
108 }
109 main {
110 char *str = "nihao";
111
112 if (outputStream != NULL) {
113 CFWriteStreamWrite(outputStream, str, strlen(line) + 1);
114 } else {
115 NSLog(@"Cannot send data!");
116 }
117 }
118 // 开辟一个线程线程函数中
119 void runLoopInThread() {
120 int res = setupSocket();
121 if (!res) {
122 exit(1);
123 }
124 CFRunLoopRun(); // 运行当前线程的CFRunLoop对象
125 }
