QUdpSocket：無法接收數據報

Question

我正在使用QUdpSocket以接收來自服務器的數據。當我使用SFML接收數據時，我可以通過SocketUdp接收數據，但是使用qt它不起作用。

void TheClass::Bind() 
{ 
    m_sock_receive = new QUdpSocket(this); 
    if (m_sock_receive->bind(QHostAddress::Any, port)) 
    { 
    std::cout << "Bind: OK" << std::endl; 
    connect(m_sock_receive, SIGNAL(readyRead()), this, SLOT(QtReceive())); 
    } 
    else 
     std::cout << "Bind: NOK" << std::endl; 
} 

void TheClass::QtReceive() 
{ 
    std::cout << "Pending data !" << std::endl; 
} 

Answer 1

我會在綁定之前進行連接。在綁定之後，readyRead可能會在connect調用完成之前觸發。如果您不清空掛起的數據報，readyRead將不會再次觸發。

Answer 2

爲了將SIGNAL（readyRead（））連接到任何插槽，QUdpSocket必須位於QAbstractSocket :: BoundState中。雖然在連接之前調用綁定，但QUdpSocket上的綁定會進行非阻塞調用，也就是說綁定可能會延遲。爲了確保你的信號（readyRead（））連接到SLOT（QtReceive（））綁定已完成，QUdpSocket提供處於綁定狀態後，執行以下操作：

void TheClass::Bind() 
{ 
    m_sock_receive = new QUdpSocket(this); 
    connect(m_sock_receive, SIGNAL(stateChanged(QAbstractSocket::SocketState)), 
     this, SLOT(onSocketStateChange(QAbstractSocket::SocketState))); 
    if (m_sock_receive->bind(QHostAddress::Any, port)) 
    { 
    std::cout << "Bind: OK" << std::endl; 
    } 
    else 
     std::cout << "Bind: NOK" << std::endl; 
} 

void TheClass::QtReceive() 
{ 
    std::cout << "Pending data !" << std::endl; 
} 

void TheClass::onSocketStateChange (QAbstractSocket::SocketState state) { 
    if (state == QAbstractSocket::BoundState) { 
     connect(m_sock_receive, SIGNAL(readyRead()), this, SLOT(QtReceive())); 
    } 
}