lededev

struct InOutData {
    pid: u32,   // in
    hwnd: HWND  // out
}

unsafe extern "system" fn callback(hwnd: HWND, lparam: LPARAM) -> BOOL {
    let s: &mut InOutData = mem::transmute(lparam);  // LPARAM转回结构体指针
    if ((*s).pid == GetWindowThreadProcessId(hwnd, Some(ptr::null_mut()))) {
        (*s).hwnd = hwnd;
        return false.into();