Failed to sent virtual key "Alt+Space" using "SendInput()" in C with GCC/Mingw32 Compiler?

Question

I tried to pop up the menu using Windows API: SendInput(), but totally failed every time.

#include <windows.h>
int main (void)
{
    INPUT Alt_Space[4] = {0};

    Alt_Space[0].type = INPUT_KEYBOARD;  // Alt Key down
    Alt_Space[0].ki.wVk = VK_MENU;

    Alt_Space[1].type = INPUT_KEYBOARD;  // Space Key down
    Alt_Space[1].ki.wVk = VK_SPACE;

    Alt_Space[2].type = INPUT_KEYBOARD;  // Space Key up
    Alt_Space[2].ki.dwFlags = KEYEVENTF_KEYUP;
    Alt_Space[2].ki.wVk = VK_SPACE;

    Alt_Space[3].type = INPUT_KEYBOARD;  // Alt Key up
    Alt_Space[3].ki.dwFlags = KEYEVENTF_KEYUP;
    Alt_Space[3].ki.wVk = VK_MENU;

    SendInput ( 4, Alt_Space, sizeof(INPUT));

    system ("pause");
}

Can anyone know why this code failed to pop up the menu? Thanks.

Compile Command:

 mingw32-gcc.exe -O3 -c "Console.c" -o "Console.o"
 mingw32-gcc.exe -o "Console.exe" "Console.o"

Answer 1

Though I didn't use SendInput(), keybd_event() works perfectly with GCC/Mingw32.

I answered my own question, and leave it in order to provide some idea to whom have the same problem.

// Event
#define KEYEVENTF_KEYDOWN 0x0000

// ALT + SPACE
#define SCAN_CODE_ALT     0x38
#define SCAN_CODE_SPACE   0x39
keybd_event ( VK_MENU  , SCAN_CODE_ALT  , KEYEVENTF_KEYDOWN, 0);
keybd_event ( VK_SPACE , SCAN_CODE_SPACE, KEYEVENTF_KEYDOWN, 0);
keybd_event ( VK_SPACE , SCAN_CODE_SPACE, KEYEVENTF_KEYUP  , 0);
keybd_event ( VK_MENU  , SCAN_CODE_ALT  , KEYEVENTF_KEYUP  , 0);

// UP * 2
#define SCAN_CODE_UP      0x48
keybd_event ( VK_UP    , SCAN_CODE_UP   , KEYEVENTF_KEYDOWN, 0);
keybd_event ( VK_UP    , SCAN_CODE_UP   , KEYEVENTF_KEYUP  , 0);
keybd_event ( VK_UP    , SCAN_CODE_UP   , KEYEVENTF_KEYDOWN, 0);
keybd_event ( VK_UP    , SCAN_CODE_UP   , KEYEVENTF_KEYUP  , 0);

// Enter
#define SCAN_CODE_ENTER   0x1C
keybd_event ( VK_RETURN, SCAN_CODE_ENTER, KEYEVENTF_KEYUP  , 0);
keybd_event ( VK_RETURN, SCAN_CODE_ENTER, KEYEVENTF_KEYDOWN, 0);