Question

我正在尝试使用GCDAsyncUdpSocket创建客户端套接字。我看不到net cat的任何内容，看起来第一次发送后连接就关闭了。

运行我的代码时，我会收到这些日志：

2014-04-16 14:00:48.434 WL002[20518:60b] is connected
2014-04-16 14:00:48.435 WL002[20518:60b] able to start receiving
2014-04-16 14:00:48.436 WL002[20518:60b] Ready
2014-04-16 14:00:48.437 WL002[20518:60b] the local address,host,port: <1002dd8e 7f000001 00000000 00000000>,127.0.0.1,56718
2014-04-16 14:00:48.437 WL002[20518:60b] the connected address,host,port: <10020017 7f000001 00000000 00000000>,127.0.0.1,23
2014-04-16 14:00:48.704 WL002[20518:60b] did connect to address:<10020017 7f000001 00000000 00000000>
2014-04-16 14:00:48.705 WL002[20518:60b] connection status:  1
2014-04-16 14:00:48.718 WL002[20518:60b] ATTEMPT SENDING (0): Hello World test
2014-04-16 14:00:48.719 WL002[20518:60b] connection status:  0
2014-04-16 14:00:48.719 WL002[20518:60b] ATTEMPT SENDING (1): Hello World test 2
2014-04-16 14:00:48.720 WL002[20518:60b] connection status:  0
2014-04-16 14:00:48.720 WL002[20518:60b] ATTEMPT SENDING (2): Hello World test 3
2014-04-16 14:00:48.722 WL002[20518:60b] socket sent with tag 0
2014-04-16 14:00:48.722 WL002[20518:60b] socket did close error Error Domain=GCDAsyncUdpSocketErrorDomain Code=4 "Socket closed" UserInfo=0xaa6b820 {NSLocalizedDescription=Socket closed}
2014-04-16 14:00:48.723 WL002[20518:60b] socket did not sent with tag 1 with error: Error Domain=GCDAsyncUdpSocketErrorDomain Code=1 "You must specify destination of packet for a non-connected socket" UserInfo=0x9599ba0 {NSLocalizedDescription=You must specify destination of packet for a non-connected socket}
2014-04-16 14:00:48.723 WL002[20518:60b] socket did not sent with tag 2 with error: Error Domain=GCDAsyncUdpSocketErrorDomain Code=1 "You must specify destination of packet for a non-connected socket" UserInfo=0x9591270 {NSLocalizedDescription=You must specify destination of packet for a non-connected socket}

我的代码是：

//wifi setup
    if (udpSocket == nil)
    {
        [self setupSocket];
    }


    NSLog(@"the local address,host,port: %@,%@,%d",[udpSocket localAddress],[udpSocket localHost],[udpSocket localPort]);
    NSLog(@"the connected address,host,port: %@,%@,%d",[udpSocket connectedAddress],[udpSocket connectedHost],[udpSocket connectedPort]);



    return YES;
}

- (void)setupSocket
{
    NSError *err = nil;
    udpSocket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()];
    udpSocket.delegate = self;

    if (![udpSocket bindToPort:0 error:&err])
    {
        NSLog(@"Error binding: %@", err)
        ;
        return;
    }


    //ensure socket is connected
    if (![udpSocket connectToHost:@"127.0.0.1" onPort:23 error:&err]) {
        NSLog(@"not connected");
        return;
    }
    else NSLog(@"is connected");

    //start ablitiy to continuously receive data
    if (![udpSocket beginReceiving:&err])
    {
        NSLog(@"Error receiving: %@", err);
        return;
    }
    else NSLog(@"able to start receiving");
    [udpSocket setIPVersionNeutral];

    NSLog(@"Ready");

}



- (void)send:(NSString *)msg
{

    NSLog(@"connection status:  %hhd",[udpSocket isConnected]);
    if ([msg length] == 0)
    {
        NSLog(@"Message required");
        return;
    }

    NSData *data = [msg dataUsingEncoding:NSUTF8StringEncoding];
    [udpSocket sendData:data withTimeout:5 tag:tag];

    NSLog(@"ATTEMPT SENDING (%i): %@", (int)tag, msg);

    tag++;
}

- (void)udpSocket:(GCDAsyncUdpSocket *)sock didConnectToAddress:(NSData *)address
{
    NSLog(@"did connect to address:%@", address);
    [self send:@"Hello World test"];
    [self send:@"Hello World test 2"];
    [self send:@"Hello World test 3"];
}

我遇到的问题是：

网猫（nc -lk 23）
发送1个数据包后，与主机和端口的连接消失

我认为第二个错误可能导致第一个错误，但我不知道为什么。我已经找到了答案，但由于我是插座的初学者，所以找不到任何我能理解的内容。

感谢您的帮助。

使用GCDAsyncUdpSocket创建客户端套接字，在网络上没有看到任何内容，并在1次发送后关闭连接

0 个答案: