以下是我在Zeus程序员编辑器中用于执行此操作的代码的简要摘要:
第 1 步:定义几个消息结构来保存 Windows 消息详细信息:
typedef struct
{
MSG msg;
LRESULT lResult;
} xMessage;
struct xWM_COMMAND
{
HWND hwnd;
UINT Msg;
WORD ItemID;
WORD NotifyCode;
HWND Ctl;
LRESULT lResult;
};
//-- unpack a message buffer
#define MSG_UNPACK(var, id, msg) x##id *var = (x##id *)(msg);
第 2 步:使用一些特殊方法定义一个基窗口类:
class xWindow
{
protected:
//-- windows callback function
static LRESULT CALLBACK wndProc(HWND hwnd, UINT msg,
WPARAM wParam,
LPARAM lParam);
//-- a message dispatch method
void dispatch(HWND hwnd, UINT uMessageID, WPARAM wParam,
LPARAM lParam, LRESULT &Result);
//-- method for command message dispatching
virtual void dispatchToCmdMap(xMessage *pMessage);
//-- method for windows message dispatching
virtual void dispatchToMsgMap(xMessage *pMessage);
};
第 3 步:定义一些宏来发送 Windows 消息:
#define BEGIN_MSG_MAP \
protected: \
virtual void dispatchToMsgMap(xMessage *msg)\
{ \
if (msg->msg.message == WM_NULL) \
{ \
return; \
}
#define MSG_HANDLER(meth, wm_msg) \
else if (msg->msg.message == wm_msg) \
{ \
this->meth(msg); \
return; \
}
#define END_MSG_MAP(base) \
else if (msg->msg.message == WM_COMMAND) \
{ \
this->dispatchToCmdMap(msg); \
return; \
} \
else if (msg->msg.message == WM_NOTIFY) \
{ \
this->dispatchToNotifyMap(msg); \
return; \
} \
\
base::dispatchToMsgMap(msg); \
};
#define BEGIN_CMD_MAP \
virtual void dispatchToCmdMap(xMessage *msg)\
{ \
MSG_UNPACK(Cmd, WM_COMMAND, msg); \
\
if (Cmd->ItemID == 0) \
{ \
/* not allowed */ \
}
#define CMD_HANDLER(meth, cmd_id) \
else if (Cmd->ItemID == cmd_id) \
{ \
this->meth(Cmd->ItemID); \
}
#define END_CMD_MAP(base) \
else \
{ \
base::dispatchToCmdMap(msg); \
} \
};
第 4 步:定义调度程序方法:
void xWindow::dispatch(HWND, UINT uMessageID, WPARAM wParam,
LPARAM lParam, LRESULT &Result)
{
xMessage message;
//-- build up a message packet
message.msg.message = uMessageID;
message.msg.wParam = wParam;
message.msg.lParam = lParam;
message.lResult = 0;
//-- dispatch the message
this->dispatchToMsgMap(&message);
}
步骤 5:定义静态窗口过程方法(注意:该方法需要在第一次注册类时用作窗口类的 Window 过程):
LRESULT CALLBACK xWindow::wndProc(HWND hwnd, UINT msg,
WPARAM wParam,
LPARAM lParam)
{
LRESULT lResult = 0;
//-- look for the creation message
if (msg == WM_NCCREATE)
{
CREATESTRUCT *pCreateData = (CREATESTRUCT*)lParam;
//-- get the window object passed in
xWindow *pWindow = (xWindow)pCreateData->lpCreateParams;
if (pWindow)
{
//-- attach the window object to the hwnd
SetWindowLong(hwnd, pWindow);
//-- let the window object dispatch the message
pWindow->dispatch(hwnd, msg, wParam, lParam, lResult);
}
else
{
//-- leave the message to windows
lResult = DefWindowProc(hwnd, msg, wParam, lParam);
}
}
else if (hwnd)
{
//-- get the object attached to the hwnd
xWindow *pWindow = (xWindow *)GetWindowLong(hwnd);
//-- check to see if we have an object window attached to the handle
if (pWindow)
{
//-- let the window object dispatch the message
pWindow->dispatch(hwnd, msg, wParam, lParam, lResult);
}
else
{
//-- leave the message to windows
lResult = ::DefWindowProc(hwnd, msg, wParam, lParam);
}
}
return lResult;
}
现在,使用这个基类可以定义一个新的窗口类,如下所示:
class MyWindow : public xWindow
{
protected:
//-- the WM_COMMAND message handlers
virtual void onAdd(int);
virtual void onDelete(int);
//-- the WM_CLOSE message handler
virtual void onClose(xMessage *pMessage);
//-- the WM_SIZE message handler
virtual void onSize(xMessage *pMessage);
public:
//-- ctor and dtor
MyWindow();
virtual ~MyWindow();
BEGIN_MSG_MAP
//-- command message handlers
CMD_HANDLER(onAdd , IDPB_ADD )
CMD_HANDLER(onDelete, IDPB_DELETE)
//-- other message handling
MSG_HANDLER(onClose , WM_CLOSE)
MSG_HANDLER(onSize , WM_SIZE )
END_MSG_MAP(xWindow)
};
编辑:此代码如何工作。
理解此代码如何工作的秘诀是记住xWindow类中的wndProc只不过是在注册 Win32 窗口时传递给RegisterClassEx的Win32窗口过程。
现在,如果您查看wndProc代码,您会看到它进行了一些设置和检查,但通常它只是将 Windows 消息发送到调度方法。
dispatch方法更简单,因为它只是将 Windows 消息打包到一个易于移动的结构中,然后将其发送到dispatchToMsgMap方法。
现在查看MyWindow类,您将看到以下代码:
BEGIN_MSG_MAP
//-- command message handlers
CMD_HANDLER(onAdd , IDPB_ADD )
CMD_HANDLER(onDelete, IDPB_DELETE)
//-- other message handling
MSG_HANDLER(onClose , WM_CLOSE)
MSG_HANDLER(onSize , WM_SIZE )
END_MSG_MAP(xWindow)
这段代码只是使用了前面定义的宏。如果您仔细查看这些宏,您会发现上面的代码实际上是在创建一个dispatchToMsgMap方法。这与dispatch方法调用的dispatchToMsgMap方法完全相同。
我知道这种处理 Windows 消息的方法确实有效,因为我在Zeus for Windows编辑器中使用了完全相同的方法。