Question

I coded the code below. I’ve used it in my program and it seems to work.
Anyway, I’m asking if is it correct.

int SendMessageWMSIZE(HWND hwnd) {
    RECT rc;
    GetClientRect(hwnd,&rc);
    int lParam_my;
    short low=rc.right-rc.left; // LOWORD
    short high=rc.bottom-rc.top; // HIWORD
    lParam_my=(high<<16)|low;  // construct an int 32 from two int 16

    SendMessage(hwnd, WM_SIZE, 0, lParam_my);

    return lParam_my;
}

Don’t I have to change the “short” with “int” (I can shift an 32 int by 16, but shifting a 16 by 16)?

Why it works either if I use “short” or “int” instead of shorts?

Answer 1

It would be more idiomatic to use the MAKELPARAM macro.

SendMessage(hwnd, WM_SIZE, 0, MAKELPARAM(low, high));