Question

我用一个像这样的图书馆:

void onReceive (Lacewing::Server &Server, Lacewing::Server::Client &Client,
                char * Data, int Size) {
  /* callback body */
}

Server.onReceive (onReceive); /* to register the handler */

我愿以一个能够决定何时收到包装单(观察器型号)的类别来总结一下。

我怎么能用回头来这样做? 图书馆没有界定继承的接口。

成就

Answer 1

自您重新使用校正以来,每组都有一个<条码>,即:

/* class method */

void MyServer::onReceive (Lacewing::Server &Server, Lacewing::Server::Client &Client,
            char * Data, int Size)
{
     /* callback body - this is inside the class */
}


/* global function wraps the class method */

void onReceive (Lacewing::Server &Server, Lacewing::Server::Client &Client,
            char * Data, int Size)
{
    ((MyServer *) Server.Tag)->onReceive (Server, Client, Data, Size);
}

之后:

Server.Tag = myServerInstance; /* set the class instance pointer */
Server.onReceive (::onReceive); /* register the global function */

Answer 2

如果我正确理解你的话,你可以采取两种不同的方式。

假设这一反馈结构正在使用数据参数,使你能够把自己的数据传递给反馈职能(共同模式),你可以这样做:

class MyProcessingClass
{
public:
    MyProcessingClass();
    virtual ~MyProcessingClass();

    // Do whatever processing in this method
    virtual void onReceive(Lacewing::Server &Server, Lacewing::Server::Client &Client);
}

void onReceive (Lacewing::Server &Server, Lacewing::Server::Client &Client,
                char * Data, int Size)
{
    if ( Data != NULL )
    {
        MyProcessingClass *handler = reinterpret_cast<MyProcessingClass *>(Data);
        handler->onReceive( Server, Client );
    }
}

或者,如果数据点是你需要处理的,而不是“用户数据点”,那么你可能不得不使用单一吨、某种全球变数或类似数据。在我的经验中,这是使用反馈的不太常见的方法,希望是你重新处理。

MyProcessingClass g_Processor;

MyProcessingClass *GetProcessor()
{
    return &g_Processor; // or some other way of getting your instance
}

void onReceive (Lacewing::Server &Server, Lacewing::Server::Client &Client,
                char * Data, int Size)
{
    MyProcessingClass *handler = GetProcessor();
    if ( handler != NULL )
    {
        handler->onReceive( Server, Client );
    }
}

友情链接