TCP UDP 套接字

TCP是全双工的，安全的，不过效率低，内存消耗大

UDP是半双工的，不安全，不过效率高，内存消耗小

在工程中导入三方库AsyncSocket

TCP是需要三次握手的

- (void)viewDidLoad
{
    [super viewDidLoad];
    _mArray = [[NSMutableArray alloc] init];
    //客户端
    _clientSocket = [[AsyncSocket alloc] initWithDelegate:self];
    //服务端
    _serverSocket = [[AsyncSocket alloc] initWithDelegate:self];
    
    //监听有没有客户端连接
    [_serverSocket acceptOnPort:5678 error:nil];
}


//监听到客户端连接
- (void)onSocket:(AsyncSocket *)sock didAcceptNewSocket:(AsyncSocket *)newSocket
{
    [_mArray addObject:newSocket];
    //监听客户端发送消息
    [newSocket readDataWithTimeout:-1 tag:0];//Timeout连接超时，-1指的是永远不超时，永远等待
    
    
}

//当监听到克华短发送了消息
- (void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
    NSString *str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    if(_textView.text.length >= 100 ){
        _textView.text = @"";
    }
    //消息显示到textView上面 sock.connectedHost客户端地址
    _textView.text = [NSString stringWithFormat:@"%@%@:%@
",_textView.text,sock.connectedHost,str];
    //继续监听客户端发送消息
    [sock readDataWithTimeout:-1 tag:0];//一直监听，递归
}

//连接
- (void)conToHost:(id)sender
{
    //如果已经连接，先断开
    if(_clientSocket.isConnected){
        [_clientSocket disconnect];
    }
    //连接服务端
    [_clientSocket connectToHost:_ipField.text onPort:5678 withTimeout:20 error:nil];
}


//连接成功
- (void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
    NSLog(@"连接成功");
}


//发送
- (void)sendText:(id)sender
{
    NSData *data = [_sendField.text dataUsingEncoding:NSUTF8StringEncoding];
    _sendField.text = @"";
    [_clientSocket writeData:data withTimeout:20 tag:0];
    
}

//发送成功
- (void)onSocket:(AsyncSocket *)sock didWriteDataWithTag:(long)tag
{
    NSLog(@"发送成功");
}

@end

UDP相对于TCP是简单的，不管服务器端在不在，直接发送信息

- (void)viewDidLoad
{
    [super viewDidLoad];
    //发送端
    _sendSocket = [[AsyncUdpSocket alloc] initWithDelegate:self];
    //绑定端口
    [_sendSocket bindToPort:5555 error:nil];
    
    //接收端
    _recvSocket = [[AsyncUdpSocket alloc] initWithDelegate:self];
    [_recvSocket bindToPort:6666 error:nil];
    
    //监听有没有人发送消息
    [_recvSocket receiveWithTimeout:-1 tag:0];
}



//接收端,监听到有人给它发消息
- (BOOL)onUdpSocket:(AsyncUdpSocket *)sock didReceiveData:(NSData *)data withTag:(long)tag fromHost:(NSString *)host port:(UInt16)port
{
    //解析xml
    GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithData:data options:0 error:nil];
    //解析message
    GDataXMLElement *messageEle = doc.rootElement;
    //解析name
    GDataXMLElement *nameEle = [[messageEle elementsForName:@"name"] lastObject];
    //解析text
    GDataXMLElement *textEle = [[messageEle elementsForName:@"text"] lastObject];
    //显示出来
    if(_textView.text.length >=100){
        _textView.text = @"";
    }
    _textView.text = [NSString stringWithFormat:@"%@%@:%@
",_textView.text,nameEle.stringValue,textEle.stringValue];
    //继续监听
    [_recvSocket receiveWithTimeout:-1 tag:0];
    return YES;
}


//发送端
- (void)sendText:(id)sender
{
    /*
     <?xml>
     <message>
         <name>...</name>
         <text>.....</text>
     </message>
     */
    GDataXMLElement *messageEle = [GDataXMLElement elementWithName:@"message"];
    GDataXMLElement *nameEle = [GDataXMLElement elementWithName:@"name" stringValue:@"iOS"];
    GDataXMLElement *textEle = [GDataXMLElement elementWithName:@"text" stringValue:_sendField.text];
    [messageEle addChild:nameEle];
    [messageEle addChild:textEle];
    
    //加声明
    GDataXMLDocument *doc = [[GDataXMLDocument alloc] initWithRootElement:messageEle];
    [doc setCharacterEncoding:@"utf-8"];//编码格式
    
    //发送消息
    [_sendSocket sendData:doc.XMLData toHost:_ipField.text port:6666 withTimeout:20 tag:0];
}

//发送消息后
- (void)onUdpSocket:(AsyncUdpSocket *)sock didSendDataWithTag:(long)tag
{
    
}


- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [self.view endEditing:YES];
}


@end