进程间的实时通讯方案： local socket（解决扩展和容器应用的实时通讯问题）

platform :ios, '8.0'
inhibit_all_warnings!

#use_frameworks!
target 'localScoket' do
   pod 'CocoaAsyncSocket'
end

target 'localScoket4client' do
   pod 'CocoaAsyncSocket'
end

#import <GCDAsyncSocket.h>

@interface ViewController ()

{
    GCDAsyncSocket *_serverSocket;
}

@property(strong,nonatomic)NSMutableArray *clientSocket;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    _clientSocket = [NSMutableArray array];
    
    
    //创建服务端的socket，注意这里的是初始化的同时已经指定了delegate
    _serverSocket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
    
    
    
    [self startChatServer];
    
    
}



-(void)startChatServer{
    //打开监听端口
    NSError *err;
    [_serverSocket acceptOnPort:12345 error:&err];
    if (!err) {
        NSLog(@"Server 服务开启成功");
    }else{
        NSLog(@"Server 服务开启失败");
    }
}
#pragma mark 有客户端建立连接的时候调用
-(void)socket:(GCDAsyncSocket *)sock didAcceptNewSocket:(GCDAsyncSocket *)newSocket{
    //sock为服务端的socket，服务端的socket只负责客户端的连接，不负责数据的读取。newSocket为客户端的socket    NSLog(@"服务端的socket %p 客户端的socket %p",sock,newSocket);
    //保存客户端的socket，如果不保存，服务器会自动断开与客户端的连接（客户端那边会报断开连接的log）
    NSLog(@"Server %s",__func__);
    [self.clientSocket addObject:newSocket];
    
    //newSocket为客户端的Socket。这里读取数据
    [newSocket readDataWithTimeout:-1 tag:100];
}
#pragma mark 服务器写数据给客户端
-(void)socket:(GCDAsyncSocket *)sock didWriteDataWithTag:(long)tag{
    NSLog(@"Server %s",__func__);
    [sock readDataWithTimeout:-1 tag:100];
}

#pragma mark 接收客户端传递过来的数据
-(void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag{
    //sock为客户端的socket
    NSLog(@"Server 客户端的socket %p",sock);
    //接收到数据
    NSString *receiverStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"Server receiverStr :%@",receiverStr);
    // 把回车和换行字符去掉，接收到的字符串有时候包括这2个，导致判断quit指令的时候判断不相等
    receiverStr = [receiverStr stringByReplacingOccurrencesOfString:@"\r" withString:@""];
    receiverStr = [receiverStr stringByReplacingOccurrencesOfString:@"\n" withString:@""];
    
    //判断是登录指令还是发送聊天数据的指令。这些指令都是自定义的
    //登录指令
    if([receiverStr hasPrefix:@"iam:"]){        // 获取用户名
        NSString *user = [receiverStr componentsSeparatedByString:@":"][1];
        // 响应给客户端的数据
        NSString *respStr = [user stringByAppendingString:@"has joined"];
        [sock writeData:[respStr dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:0];
    }
    //聊天指令
    if ([receiverStr hasPrefix:@"msg:"]) {
        //截取聊天消息
        NSString *msg = [receiverStr componentsSeparatedByString:@":"][1];
        [sock writeData:[msg dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:0];
    }
    //quit指令
    if ([receiverStr isEqualToString:@"quit"]) {
        //断开连接
        [sock disconnect];
        //移除socket
        [self.clientSocket removeObject:sock];
    }
    NSLog(@"Server %s",__func__);
}

#import <GCDAsyncSocket.h>

@interface ViewController ()


{
     GCDAsyncSocket *_clientSocket;
}


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    [self connectToServer];

    
    
}

- (void) connectToServer{
    //1.主机与端口号
    NSString *host = @"127.0.0.1";
    int port = 12345;
    
    //初始化socket，这里有两种方式。分别为是主/子线程中运行socket。根据项目不同而定
    _clientSocket = [[GCDAsyncSocket alloc]
                     initWithDelegate:self delegateQueue:dispatch_get_main_queue()];//这种是在主线程中运行
    //_socket = [[GCDAsyncSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)]; 这种是在子线程中运行
    
    //开始连接
    NSError *error = nil;
    if (![_clientSocket connectToHost:host onPort:port error:&error])
    {
        NSLog(@"Client Error connecting: %@", error);
    }
    
}


-(IBAction)login:(id)sender{
    //登录String
    NSString *loginStr = @"iam:I am login!";
    NSData *loginData = [loginStr dataUsingEncoding: NSUTF8StringEncoding];
    //发送登录指令。-1表示不超时。tag200表示这个指令的标识，很大用处
    [_clientSocket writeData: loginData withTimeout:-1 tag:200];
}

//发送聊天数据
-(IBAction) sendMsg: (id)sender{
    NSString *sendMsg = @"msg:I send message to u!";
    NSData *sendData = [sendMsg dataUsingEncoding:NSUTF8StringEncoding];
    [_clientSocket writeData:sendData withTimeout:-1 tag:201];
}

#pragma mark -socket的代理

#pragma mark 连接成功

-(void)socket:(GCDAsyncSocket *)sock didConnectToHost:(NSString *)host port:(uint16_t)port{
    //连接成功
    NSLog(@"Client %s",__func__);
}

#pragma mark 断开连接
-(void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err{
    if (err) {
        NSLog(@"Client 连接失败");
    }else{
        NSLog(@"Client 正常断开");
    }
}

#pragma mark 数据发送成功
-(void)socket:(GCDAsyncSocket *)sock didWriteDataWithTag:(long)tag{
    NSLog(@"Client %s",__func__);
    //发送完数据手动读取
    [sock readDataWithTimeout:-1 tag:tag];//不然当收到信息后不会执行读取回调方法。
}

#pragma mark 读取数据
-(void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag{
    NSString *receiverStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    
    if (tag == 200) {
        //登录指令
    }else if(tag == 201){
        //聊天数据
    }
    NSLog(@"Client %s %@",__func__,receiverStr);
}

#import <sys/types.h>
#import <sys/socket.h>
#import <ifaddrs.h>
#import <arpa/inet.h>

// Get IP Address
- (NSString *)getIPAddress {
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    // retrieve the current interfaces - returns 0 on success
    success = getifaddrs(&interfaces);
    if (success == 0) {
        // Loop through linked list of interfaces
        temp_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 iPhone
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
                    // Get NSString from C String
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    // Free memory
    freeifaddrs(interfaces);
    NSLog(@"%@",address);// IP 地址
    return address;
}