Windows Boost:：带有临时端口的asio UDP广播

我在boost:：asio下的udp广播事务中遇到问题，与以下代码片段有关。因为我试图在这个实例中广播，所以deviceIP=“255.255.255.255”。devicePort是为我的设备指定的管理端口。我想使用临时本地端口，因此如果可能的话，我更希望连接后不必使用socket.bind（），代码通过设置localPort=0来支持单播

boost::asio::ip::address_v4 targetIP = boost::asio::ip::address_v4::from_string(deviceIP);
m_targetEndPoint = boost::asio::ip::udp::endpoint(targetIP, devicePort);

m_ioServicePtr = boost::shared_ptr<boost::asio::io_service>(new boost::asio::io_service);
m_socketPtr = boost::shared_ptr<boost::asio::ip::udp::socket>(new boost::asio::ip::udp::socket(*m_ioServicePtr));
m_socketPtr->open(m_targetEndPoint.protocol());

m_socketPtr->set_option(boost::asio::socket_base::broadcast(true));

// If no local port is specified, default parameter is 0
// If local port is specified, bind to that port.
if(localPort != 0)
{
  boost::asio::ip::udp::endpoint localEndpoint(boost::asio::ip::address_v4::any(), localPort);
  m_socketPtr->bind(localEndpoint);
}

if(m_forceConnect)
  m_socketPtr->connect(m_targetEndPoint);

this->AsyncReceive(); // Register Asynch Recieve callback and buffer
m_socketThread = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&MyNetworkBase::RunSocketThread, this))); // Start thread running io_service process

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在这里，我提取初始临时端口号并尝试绑定到它，但有趣的是，当我尝试绑定时会引发无效参数异常。

好的，我找到了解决此问题的方法。在linux下这是不必要的，但在windows下，我发现如果您既不绑定也不连接，那么在调用asynch_receive_from（）之前，您必须先传输一些内容，该调用包含在我的this->asynch_receive（）方法中

我的解决方案是，在windows下进行asynch_receive调用之前，立即进行空字符串的虚拟传输，因此修改后的代码变成：

m_socketPtr->set_option(boost::asio::socket_base::broadcast(true));

// If no local port is specified, default parameter is 0
// If local port is specified, bind to that port.
if(localPort != 0)
{
  boost::asio::ip::udp::endpoint localEndpoint(boost::asio::ip::address_v4::any(), localPort);
  m_socketPtr->bind(localEndpoint);
}

if(m_forceConnect)
  m_socketPtr->connect(m_targetEndPoint);

// A dummy TX is required for the socket to acquire the local port properly under windoze
// Transmitting an empty string works fine for this, but the TX must take place BEFORE the first call to Asynch_receive_from(...)
#ifdef WIN32
m_socketPtr->send_to(boost::asio::buffer("", 0), m_targetEndPoint);
#endif

this->AsyncReceive(); // Register Asynch Recieve callback and buffer
m_socketThread = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&MyNetworkBase::RunSocketThread, this)));

m_socketPtr->set_选项（boost:：asio:：socket_base:：broadcast（true））；
//如果未指定本地端口，则默认参数为0
//如果指定了本地端口，则绑定到该端口。
如果（localPort！=0）
{
boost:：asio:：ip:：udp:：endpoint localEndpoint（boost:：asio:：ip:：address\u v4:：any（），localPort）；
m_socketPtr->bind（localEndpoint）；
}
如果（m_forceConnect）
m_socketPtr->connect（m_targetEndPoint）；
//插座需要一个虚拟TX，以便在windoze下正确获取本地端口
//传输空字符串可以很好地实现这一点，但发送必须在从（…）首次调用Asynch_receive_之前进行
#ifdef WIN32
m_socketPtr->send_to（boost:：asio:：buffer（“，0”），m_targetEndPoint）；
#恩迪夫
此->AsyncReceive（）；//注册异步接收回调和缓冲区
m_socketThread=boost:：shared_ptr（新的boost:：thread（boost:：bind（&MyNetworkBase:：RunSocketThread，this））；

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在我的书中，这有点像黑客，但它比实现所有的需求要好得多，将对异步接收方的调用推迟到第一次传输之后

当我在Linux中使用m_forceConnect=false和localPort=0运行代码时，一切运行正常。数据包从临时端口广播，并且在节目中正确接收对该数据包的回复。您收到的10022错误代码表明您正在使用Windows。也许这是Windows特有的问题？

m_socketPtr->set_option(boost::asio::socket_base::broadcast(true));

// If no local port is specified, default parameter is 0
// If local port is specified, bind to that port.
if(localPort != 0)
{
  boost::asio::ip::udp::endpoint localEndpoint(boost::asio::ip::address_v4::any(), localPort);
  m_socketPtr->bind(localEndpoint);
}

if(m_forceConnect)
  m_socketPtr->connect(m_targetEndPoint);

// A dummy TX is required for the socket to acquire the local port properly under windoze
// Transmitting an empty string works fine for this, but the TX must take place BEFORE the first call to Asynch_receive_from(...)
#ifdef WIN32
m_socketPtr->send_to(boost::asio::buffer("", 0), m_targetEndPoint);
#endif

this->AsyncReceive(); // Register Asynch Recieve callback and buffer
m_socketThread = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&MyNetworkBase::RunSocketThread, this)));