1、AsyncSocket

• 基于 CFSocket、GCD 进行的封装（OC）。

• 支持 TCP 和 UDP。

• 完整的回调函数（用于处理各种回调事件，连接成功，断开连接，收到数据等）。

• 需要注意的问题：

  • 1、Socekt 连接成功回调方法中主动调用：[self.socket readDataWithTimeout:-1 tag:0];，相当于主动添加一个读取请求，不然不会执行读取信息回调方法。
  • 2、读取信息回调方法中，读取完信息后，主动调用一下 [self.socket readDataWithTimeout:-1 tag:0];，读取完信息后，重新向队列中添加一个读取请求，不然当收到信息后不会执行读取回调方法。

2、基本使用

2.1 Client 客户端

• TCP 客户端

      #import "GCDAsyncSocket.h"@interface ViewController () <GCDAsyncSocketDelegate>@property (weak, nonatomic) IBOutlet UITextField *addrTF;@property (weak, nonatomic) IBOutlet UITextField *portTF;@property (weak, nonatomic) IBOutlet UITextField *msgTF;@property (weak, nonatomic) IBOutlet UITextView *logTV;@property (nonatomic, strong) GCDAsyncSocket *clientSockfd;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];// 创建 Socket，在主队列中处理，所有的回执都在主队列中执行。self.clientSockfd = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];}- (IBAction)connectBtnClick:(id)sender {NSError *error = nil;// Socket 连接if (![self.clientSockfd isConnected]) {[self.clientSockfd connectToHost:_addrTF.text onPort:_portTF.text.intValue error:&error];}if (error != nil) {[self showLogMessage:@"连接失败..."];}}#pragma mark - GCDAsyncSocketDelegate 协议方法// 连接成功，协议方法- (void)socket:(GCDAsyncSocket *)sock didConnectToHost:(NSString *)host port:(uint16_t)port {// 读取数据，必须添加，相当于主动添加一个读取请求，不然不会执行读取信息回调方法[self.clientSockfd readDataWithTimeout:-1 tag:0];[self showLogMessage:[NSString stringWithFormat:@"连接服务器地址：%@, 端口：%d 成功", host, port]];[self showLogMessage:[NSString stringWithFormat:@"本地地址：%@, 端口：%d", sock.localHost, sock.localPort]];}// 已经断开链接，协议方法- (void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err {[self showLogMessage:@"socket 断开连接..."];}// 读取到数据，协议方法- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag {// 注意：要想长连接，必须还要在 DidReceiveData 的 delegate 中再写一次 [_udpSocket receiveOnce:&error]// 读取数据，读取完信息后，重新向队列中添加一个读取请求，不然当收到信息后不会执行读取回调方法。[self.clientSockfd readDataWithTimeout:-1 tag:0];NSString *strMsg = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];[self showLogMessage:[NSString stringWithFormat:@"recv：%@", strMsg]];}#pragma mark - 发送数据- (IBAction)sendBtnClick:(id)sender {// Socket 发送数据[self.clientSockfd writeData:[_msgTF.text dataUsingEncoding:NSUTF8StringEncoding] withTimeout:30 tag:0];[self showLogMessage:[NSString stringWithFormat:@"send：%@", _msgTF.text]];}// 显示信息- (void)showLogMessage:(NSString *)msg {_logTV.text = [_logTV.text stringByAppendingFormat:@"%@\n", msg];}// 键盘回收- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {[self.view endEditing:YES];}@end

  

2.2 Server 服务端

• TCP 服务端

      #import <arpa/inet.h>#import <ifaddrs.h>#import "GCDAsyncSocket.h"@interface ViewController () <GCDAsyncSocketDelegate>@property (weak, nonatomic) IBOutlet UITextField *addrTF;@property (weak, nonatomic) IBOutlet UITextField *portTF;@property (weak, nonatomic) IBOutlet UITextField *msgTF;@property (weak, nonatomic) IBOutlet UITextView *logTV;@property (nonatomic, strong) GCDAsyncSocket *serverSocketfd;@property (nonatomic, strong) GCDAsyncSocket *clientSocketfd;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];NSString *ip_addr = [self getIPAddress];_addrTF.text = ip_addr;// 创建 Socket，在主队列中处理，所有的回执都在主队列中执行。self.serverSocketfd = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];}- (IBAction)listenBtnClick:(id)sender {NSError *error = nil;// Socket 监听[self.serverSocketfd acceptOnPort:_portTF.text.intValue error:&error];if (error != nil) {NSLog(@"监听出错：%@", error);} else{[self showLogMessage:@"正在监听..."];}}#pragma mark - GCDAsyncSocketDelegate 协议方法// 接收到连接请求，协议方法- (void)socket:(GCDAsyncSocket *)sock didAcceptNewSocket:(GCDAsyncSocket *)newSocket {// 读取数据，必须添加，相当于主动添加一个读取请求，不然不会执行读取信息回调方法[newSocket readDataWithTimeout:-1 tag:0];[self showLogMessage:@"收到客户端连接...."];[self showLogMessage:[NSString stringWithFormat:@"客户端地址：%@, 端口：%d", newSocket.connectedHost, newSocket.connectedPort]];self.clientSocketfd = newSocket;}// 已经断开链接，协议方法- (void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err {[self showLogMessage:@"socket 断开连接..."];}// 读取到数据，协议方法- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag {// 读取数据，读取完信息后，重新向队列中添加一个读取请求，不然当收到信息后不会执行读取回调方法。[sock readDataWithTimeout:-1 tag:0];NSString *strMsg = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];[self showLogMessage:[NSString stringWithFormat:@"recv：%@",strMsg]];}#pragma mark - 发送数据- (IBAction)sendBtnClick:(id)sender {// Socket 发送数据[self.clientSocketfd writeData:[_msgTF.text dataUsingEncoding:NSUTF8StringEncoding] withTimeout:30 tag:0];[self showLogMessage:[NSString stringWithFormat:@"send：%@", _msgTF.text]];}#pragma mark - 获取本地 IP 地址- (NSString *)getIPAddress {NSString *address = @"error";struct ifaddrs *interfaces = NULL;struct ifaddrs *temp_addr = NULL;int success = 0;// retrieve the current interfaces - returns 0 on successsuccess = getifaddrs(&interfaces);if (success == 0) {// Loop through linked list of interfacestemp_addr = interfaces;while (temp_addr != NULL) {if (temp_addr->ifa_addr->sa_family == AF_INET) {// Check if interface is en0 which is the wifi connection on the iPhoneif ([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {// Get NSString from C Stringaddress = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];}}temp_addr = temp_addr->ifa_next;}}// Free memoryfreeifaddrs(interfaces);return address;}// 显示信息- (void)showLogMessage:(NSString *)msg {_logTV.text = [_logTV.text stringByAppendingFormat:@"%@\n", msg];}// 键盘回收- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {[self.view endEditing:YES];}@end

  

2.3 UDP 通信

• UDP 通信

      #import <arpa/inet.h>#import <ifaddrs.h>#import "GCDAsyncUdpSocket.h"@interface ViewController () <GCDAsyncUdpSocketDelegate>@property (weak, nonatomic) IBOutlet UITextField *desAddrTF;@property (weak, nonatomic) IBOutlet UITextField *desPortTF;@property (weak, nonatomic) IBOutlet UITextField *locAddrTF;@property (weak, nonatomic) IBOutlet UITextField *locPortTF;@property (weak, nonatomic) IBOutlet UITextField *msgTF;@property (weak, nonatomic) IBOutlet UITextView *logTV;@property (nonatomic, strong) GCDAsyncUdpSocket *udpSocketfd;@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];NSString *ip_addr = [self getIPAddress];_locAddrTF.text = ip_addr;// 创建 Socket，在主队列中处理，所有的回执都在主队列中执行self.udpSocketfd = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];}- (IBAction)connectBtnClick:(id)sender {NSError *error = nil;// 绑定端口[self.udpSocketfd bindToPort:_locPortTF.text.intValue error:&error];if (error != nil) {NSLog(@"绑定端口出错：%@", error);return;} else{[self showLogMessage:[NSString stringWithFormat:@"绑定端口 %d 成功...", _locPortTF.text.intValue]];}// 开始接收数据[self.udpSocketfd beginReceiving:&error];if (error != nil) {NSLog(@"开始接收数据出错：%@", error);} else{[self showLogMessage:@"开始接收数据..."];}}#pragma mark - GCDAsyncUdpSocketDelegate 协议方法// 接收到的数据，协议方法- (void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)datafromAddress:(NSData *)addresswithFilterContext:(id)filterContext {NSString *strMsg = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];[self showLogMessage:[NSString stringWithFormat:@"recv：%@", strMsg]];}#pragma mark - 发送数据- (IBAction)sendBtnClick:(id)sender {// Socket 发送数据[self.udpSocketfd sendData:[_msgTF.text dataUsingEncoding:NSUTF8StringEncoding]toHost:_desAddrTF.textport:_desPortTF.text.intValuewithTimeout:30 tag:0];[self showLogMessage:[NSString stringWithFormat:@"send：%@", _msgTF.text]];}#pragma mark - 获取本地 IP 地址- (NSString *)getIPAddress {NSString *address = @"error";struct ifaddrs *interfaces = NULL;struct ifaddrs *temp_addr = NULL;int success = 0;// retrieve the current interfaces - returns 0 on successsuccess = getifaddrs(&interfaces);if (success == 0) {// Loop through linked list of interfacestemp_addr = interfaces;while (temp_addr != NULL) {if (temp_addr->ifa_addr->sa_family == AF_INET) {// Check if interface is en0 which is the wifi connection on the iPhoneif ([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {// Get NSString from C Stringaddress = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];}}temp_addr = temp_addr->ifa_next;}}// Free memoryfreeifaddrs(interfaces);return address;}// 显示信息- (void)showLogMessage:(NSString *)msg {_logTV.text = [_logTV.text stringByAppendingFormat:@"%@\n", msg];}// 键盘回收- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {[self.view endEditing:YES];}@end

  

2.4 Socket 长连接

• PublicTool.h

      @interface PublicTool : NSObject// 字典转换成 JSON 字符串+ (NSString *)JSONStringWithDic:(NSDictionary *)dic;// JSON 字符串转换成字典+ (NSDictionary *)dictionaryWithJSON:(NSString *)json;@end

• PublicTool.m

      @implementation PublicTool// 字典转成成 JSON 字符串+ (NSString *)JSONStringWithDic:(NSDictionary *)dic {NSError *error = nil;NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dicoptions:0error:&error];if (jsonData == nil) {NSLog(@"fail to get JSON from dictionary: %@, error: %@", self, error);return nil;}NSString *jsonString = [[NSString alloc] initWithData:jsonDataencoding:NSUTF8StringEncoding];return jsonString;}// JSON 字符串转换成字典+ (NSDictionary *)dictionaryWithJSON:(NSString *)json {NSError *error = nil;NSData *jsonData = [json dataUsingEncoding:NSUTF8StringEncoding];NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:jsonDataoptions:NSJSONReadingMutableContainers |NSJSONReadingAllowFragmentserror:&error];if (jsonDict == nil) {NSLog(@"fail to get dictioanry from JSON: %@, error: %@", json, error);return nil;}return jsonDict;}@end

• SocketSingleTon.h

      @interface SocketSingleTon : NSObject@property (nonatomic, copy) NSString *hostAddr;@property (nonatomic, copy) NSString *port;@property (nonatomic, copy) void(^msgLog)(NSString *);+ (instancetype)shareInstance;// 连接到服务器- (void)connectToServer;// 断开连接- (void)cutOffSocket;// 发送数据到服务器- (void)sendDataToServer:(NSData*)data;@end

• SocketSingleTon.m

      #import "GCDAsyncSocket.h"#import <netdb.h>#import <arpa/inet.h>#import "PublicTool.h"typedef NS_ENUM(NSInteger, SocketOffline) {SocketOfflineByServer,SocketOfflineByUser};@interface SocketSingleTon () <GCDAsyncSocketDelegate>@property (nonatomic, strong) GCDAsyncSocket *socket;@property (nonatomic, strong) NSTimer *beatTimer;@end@implementation SocketSingleTon+ (instancetype)shareInstance {static SocketSingleTon *shareInstance = nil;static dispatch_once_t onceToken;dispatch_once(&onceToken, ^{shareInstance = [[self alloc] init];});return shareInstance;}// 连接到服务器- (void)connectToServer {NSError *error = nil;if (self.socket != nil) {if ([self.socket isConnected]) {// 断开后再连接self.socket.userData = @(SocketOfflineByUser);[self cutOffSocket];[self.socket connectToHost:self.hostAddr onPort:self.port.intValue error:&error];} else {[self.socket connectToHost:self.hostAddr onPort:self.port.intValue error:&error];}} else {self.socket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];[self.socket connectToHost:self.hostAddr onPort:self.port.intValue error:&error];}if (error != nil) {NSLog(@"socket 连接失败：%@", error);} else {NSLog(@"socket 连接成功");}}// 断开连接- (void)cutOffSocket {self.socket.userData = @(SocketOfflineByUser);[self.socket disconnect];}#pragma mark  - GCDAsyncSocketDelegate 协议方法// 连接成功，协议方法- (void)socket:(GCDAsyncSocket *)sock didConnectToHost:(NSString *)host port:(uint16_t)port {[sock readDataWithTimeout:-1 tag:0];NSString *logStr = [NSString stringWithFormat:@"连接主机：%@:%d 成功\n", host, port];NSLog(@"%@", logStr);if (self.msgLog) {self.msgLog(logStr);}// 创建定时器，定时发送 beat 包self.beatTimer = [NSTimer scheduledTimerWithTimeInterval:5 target:self selector:@selector(longConnectToServer) userInfo:nil repeats:YES];}// 连接断开，协议方法- (void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err {self.socket = nil;[self.beatTimer invalidate];self.beatTimer = nil;if ([sock.userData  isEqual: @(SocketOfflineByUser)]) {NSLog(@"the socket have been cutted off by user");if (self.msgLog) {self.msgLog(@"the socket have been cutted off by user");}} else if (sock.userData == SocketOfflineByServer) {NSLog(@"the socket have been cutted off by server");if (self.msgLog) {self.msgLog(@"the socket have been cutted off by server");}// reconnect[self connectToServer];} else {NSLog(@"%@", err.localizedDescription);if (self.msgLog) {self.msgLog([NSString stringWithFormat:@"%@", err.localizedDescription]);}[self connectToServer];}}// 收到消息，协议方法- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag {[sock readDataWithTimeout:-1 tag:0];char buf[1024];[data getBytes:buf length:1024];NSString *receivedData = [NSString stringWithCString:buf encoding:NSUTF8StringEncoding];NSLog(@"receivedData：%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);if (receivedData.length > 0) {NSDictionary *dataDic = [PublicTool dictionaryWithJSON:receivedData];if ([dataDic[@"msgType"] isEqualToString:@"beta"]) {NSString *strMsg = [NSString stringWithFormat:@"收到心跳确认的数据：%@\n", receivedData];if (self.msgLog) {self.msgLog(strMsg);}} else if ([dataDic[@"msgType"] isEqualToString:@"normal"]) {NSString *strMsg = [NSString stringWithFormat:@"收到正常的数据：%@\n", receivedData];if (self.msgLog) {self.msgLog(strMsg);}} else if ([dataDic[@"msgType"] isEqualToString:@"exit"]) {NSString *strMsg = [NSString stringWithFormat:@"收到关闭的数据：%@\n", receivedData];if (self.msgLog) {self.msgLog(strMsg);}[self cutOffSocket];}}}// 发送数据- (void)longConnectToServer {[self sendDataToServer:[@"hello" dataUsingEncoding:NSUTF8StringEncoding]];}// 发送数据到服务器- (void)sendDataToServer:(NSData*)data {NSString *dataStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];NSMutableDictionary *dicParams = [NSMutableDictionary dictionary];if ([dataStr isEqualToString:@"hello"]) {[dicParams setValue:dataStr forKey:@"msg"];[dicParams setValue:@"beta" forKey:@"msgType"];} else {[dicParams setValue:dataStr forKey:@"msg"];[dicParams setValue:@"normal" forKey:@"msgType"];}NSData *sendData = [[PublicTool JSONStringWithDic:dicParams] dataUsingEncoding:NSUTF8StringEncoding];NSString *strMsg = [NSString stringWithFormat:@"发送数据: %@\n", [PublicTool JSONStringWithDic:dicParams]];if (self.msgLog) {self.msgLog(strMsg);}[self.socket writeData:sendData withTimeout:30 tag:0];}@end

• ViewController.m

      #import "SocketSingleTon.h"#import "PublicTool.h"@interface ViewController ()@property (weak, nonatomic) IBOutlet UITextField *addressTF;@property (weak, nonatomic) IBOutlet UITextField *portTF;@property (weak, nonatomic) IBOutlet UITextField *msgTF;@property (weak, nonatomic) IBOutlet UITextView *logTV;@end@implementation ViewController- (IBAction)connectToServer:(id)sender {// 创建 SocketSocketSingleTon *socketInstance = [SocketSingleTon shareInstance];socketInstance.hostAddr = _addressTF.text;socketInstance.port = _portTF.text;__weak __typeof (self)weakSelf = self;socketInstance.msgLog = ^(NSString *log){dispatch_async(dispatch_get_main_queue(), ^{weakSelf.logTV.text = [weakSelf.logTV.text stringByAppendingString:log];});};// 连接到服务器[socketInstance connectToServer];}- (IBAction)cutOffConnect:(id)sender {SocketSingleTon *socketInstance = [SocketSingleTon shareInstance];// 断开连接[socketInstance cutOffSocket];}- (IBAction)sendDataToServer:(id)sender {SocketSingleTon *socketInstance = [SocketSingleTon shareInstance];// 发送数据到服务器[socketInstance sendDataToServer:[_msgTF.text dataUsingEncoding:NSUTF8StringEncoding]];}- (IBAction)sendBetaDataToServer:(id)sender {SocketSingleTon *socketInstance = [SocketSingleTon shareInstance];NSMutableDictionary *dicParams = [NSMutableDictionary dictionary];[dicParams setValue:@"beta" forKey:@"msgType"];[dicParams setValue:@"hello" forKey:@"msg"];NSString *strMsg = [PublicTool JSONStringWithDic:dicParams];// 发送心跳数据到服务器[socketInstance sendDataToServer:[strMsg dataUsingEncoding:NSUTF8StringEncoding]];}- (IBAction)clearLog:(id)sender {_logTV.text = nil;}// 键盘回收- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {[self.view endEditing:YES];}@end