Why WM_KEYUP doesn't work, if WM_KEYDOWN does? [closed]

Answer 1

As @David Heffernan said that, SendInput can do this.

This is the least code.

#include <iostream>
#include <Windows.h>

using namespace std;

int main()
{
    HWND hwnd;
    INPUT input[2];
    memset(input, 0, sizeof(input));
    if (!(hwnd = FindWindow(L"AAAA", NULL)))
    {
        cout << "Couldn't find window";
    }
    else
    {
        Sleep(5000);
        input[0].type = input[1].type = INPUT_KEYBOARD;

        SetForegroundWindow(hwnd);

        input[0].ki.wVk = 'W';
        input[0].ki.dwFlags = 0;
        input[1].ki.wVk = 'W';
        input[1].ki.dwFlags = KEYEVENTF_KEYUP;
        SendInput(2, input, sizeof(INPUT));
    }

    return 0;
}

Put the key down and key up events into an array of length 2 and send them as a single atomic unit.

Set the value of ki.dwFlags to control up and down states of the key.