🚀 go-pugleaf

"Remy Lebeau (TeamB)" wrote:

> "Richard Casten" <richard.casten@aero.org> wrote in message
> news:4422FA56.83B7F39@aero.org...
>
> > How would I know what is the specific HWND of the text field?
>
>  The class name of the text window is "Static".

Thanks Remy.  I am calling the SetWindowsHookEx function with idHook parameter
equal to WH_CALLWNDPROC right before I call MessageBox.  In the hook function, I
test for the window having class name "Static". I am then trying to use the
DrawText function inside the hook function to draw a string.  It is never
drawn.  Is there a problem in using the DrawText function inside the hook
function?

This is the sample code: Only the input string to the MessageBox is drawn.

#include <windows.h>
LRESULT CALLBACK hook_proc(int nCode, WPARAM wParam, LPARAM lParam);
int main(int argc, char **argv)
{
     HHOOK hook;

     hook = SetWindowsHookEx(WH_CALLWNDPROC,hook_proc,NULL,
                             GetCurrentThreadId());

     MessageBox(NULL,"First line of error\n","Error",MB_OK);
     UnhookWindowsHookEx(hook);
     return(0);
}
LRESULT CALLBACK hook_proc(int nCode, WPARAM wParam, LPARAM lParam)
{
     CWPSTRUCT *p;
     char class_name[100];
     HDC hdc;
     RECT rect;
     static char first=1;
     char *second_line = "Second line of error";

     if(nCode < 0)
          return(CallNextHookEx(NULL,nCode,wParam,lParam));

     p = (CWPSTRUCT *)lParam;
     GetClassName(p->hwnd,class_name,sizeof(class_name));
     if(first && stricmp(class_name,"Static") == 0)
     {
          hdc = GetDC(p->hwnd);

          GetWindowRect(p->hwnd,&rect);
          DrawText(hdc,second_line,strlen(second_line),&rect,
                   DT_SINGLELINE | DT_BOTTOM);
          first = 0;

          ReleaseDC(p->hwnd,hdc);
     }

     return(CallNextHookEx(NULL,nCode,wParam,lParam));
}