Variables accessed in Window Procedure

[Malachi]

Is there any way I can pass variables (preferably by reference) to the Window Procedure so I don't have to have global variables?

[bencharluo]

up up

[SigmaSecurity]

Although I'm not really sure what bencharluo is trying to say, This is how I usually do it.

1.) Assuning your not using some predefined data type (LPSTR, LPDWORD, etc...) you will have to define your own. You can do this by creating a new structure:

struct TESTSTRUCT{
  TCHAR     byte1;
  TCHAR     byte2;
  DWORD    dword1;
  DWORD    dword2;
};

2.) Not that we have defined our new data type, can pass it to a windows procedure by using SendMessage()
(I will be use #define WM_USERDEFINED_MSG WM_USER+1 for the message type)

TESTSTRUCT ts={'a','b',1337,31337};//construct the structure
SendMessage(YourTargetWindow, WM_USERDEFINED_MSG, (WPARAM)&ts, 0);

3.) Now that we have passed our variable as a reference, we have to intercept and interpret it at the other end.
This will be somewhere inside of YourTargetWindow's window procedure function:

if(uMsg==WM_USERDEFINED_MSG){
TESTSTRUCT *ts=(TESTSTRUCT*)wParam;//oh pointers, how I love thee
TCHAR msgText[256]="";//empty text buffer
sprintf(msgText,"%c\n%c\n%d\n%d",ts->byte1,ts->byte2,ts->dword1,ts->dword1);
MessageBox(YourTargetWindow,msgText,"Here is the data that was passed",MB_OK);
}

I hope that this was helpful to you. Here is the MSDN Documentation for SendMessage() that comes in handy a lot.
http://msdn.microsoft.com/en-us/library/ms644950(VS.85).aspx

Sigma

[Malachi]

thats awesome, thanks ^.^

[SigmaSecurity]

Glad that I could help.

Sigma