Simulate double direct keyboard input in C++ - c++

Question

I found this c++ script that let you simulate a direct keyboard input, however, I need to simulate two inputs like [Ctrl + A]. I've been looking for ways to make it but I can't find the answer, if someone could help me or give me a clue I'd be grateful.
#include "stdafx.h"
#pragma comment(lib,"user32")
using namespace std;
int main()
{
char ch = 'a';
INPUT key;
memset(&key,0,sizeof(INPUT));//Zero the structure.
key.type = INPUT_KEYBOARD;
key.ki.dwExtraInfo = GetMessageExtraInfo();//<-- you will need to pinvoke this too.
key.ki.wScan =
static_cast<WORD>(MapVirtualKeyEx(VkKeyScanA(ch), MAPVK_VK_TO_VSC, GetKeyboardLayout(0)));//more pinvoking
key.ki.dwFlags = KEYEVENTF_SCANCODE;//<-- you will probably have to declare this constant somewhere-
//in your C# program.
//Ready to send the key-down event.
SendInput(1, &key, sizeof(INPUT));
Sleep(1000);//Wait one second before sending key-up.
//Sending key-up.
key.ki.dwExtraInfo = GetMessageExtraInfo();
key.ki.dwFlags = KEYEVENTF_SCANCODE | KEYEVENTF_KEYUP;//Key-up need be defined too, or just use the value.
SendInput(1, &key, sizeof(INPUT));
}
I've written this code, Ctrl press isn't working, however, 'W' press does.
int main()
{
Sleep(2000);
INPUT ip;
char key1 = VK_CONTROL, key2 = 'w';
ip.type = INPUT_KEYBOARD;
ip.ki.wScan = 0; // hardware scan code for key
ip.ki.time = 0;
ip.ki.dwExtraInfo = 0;
ip.ki.wScan = key1;
ip.ki.dwFlags = 0; // 0 for key press
SendInput(1, &ip, sizeof(INPUT));
// Press key2
ip.ki.wScan = key2;
ip.ki.dwFlags = 0; // 0 for key press
SendInput(1, &ip, sizeof(INPUT));
// Release key2
ip.ki.wScan = key2;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
SendInput(1, &ip, sizeof(INPUT));
// Release key1
ip.ki.wScan = key1;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
SendInput(1, &ip, sizeof(INPUT));
}
I've noticed if I delete the VK_CONTROL press lines, 'W' press doesn't work neither.
int main() {
Sleep(2000);
INPUT ip;
char key2 = 'w';
ip.type = INPUT_KEYBOARD;
ip.ki.wScan = 0; // hardware scan code for key
ip.ki.time = 0;
ip.ki.dwExtraInfo = 0;
// Press key2
ip.ki.wScan = key2;
ip.ki.dwFlags = 0; // 0 for key press
SendInput(1, &ip, sizeof(INPUT));
// Release key2
ip.ki.wScan = key2;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
SendInput(1, &ip, sizeof(INPUT));
}

Answer 1

To send a ctrl-a, you need to send, in order:
key-down events
VK_CONTROL
virtual code for a
key-up events
virtual code for a
VK_CONTROL
so, using VkKeyScanExW to get the virtual scan code for 'a'
key.ki.wVk = VK_CONTROL;
/* send keystroke */
key.ki.wVk = /* the virtual key code for a that you derived */
/* send keystroke */
/* set flag to keyup */
key.ki.wVk = /* Virtual code for a */
/* send keystroke */
key.ki.wVk = VK_CONTROL;
/* send keystroke */
where VK_CONTROL is the macro defined in Windows that gives you the keyboard virtual code for ctrl. Leave wScan set to 0.

Answer 2

You are sending virtual codes to the scan code parameter. The scan code for w is not 'w'.
In scan code set 1 (US keyboards), w's scan code is 0x11, and left control's scan code is 0x1D. Microsoft's Keyboard Scan Code Specification details sets 1 and 2, and can be found at https://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/scancode.doc. There are commonly 3 sets of scan codes, and they are enumerated various places on the web. Or, you can use a utility to capture your own keyboard's scan codes. Sharpkeys or AutoHotkey appear to be popular utilities for doing just this.