Question

I have searched the internet for a good system for emulating keypresses in C++.

I want to send a string to another program but as far as I can see the GenerateKey function can only send one at a time. I created code to break a string down and send each letter individually but sometimes the number of a specific letter in the alphabet is sent instead of the letter itself. (e.g. I enter “h” the computer spits out “8”)

How can I fix this and is there a better way to do it? Thank you!

#include <windows.h>
#include<iostream>
#include <winable.h>
#include <fstream>
#include<time.h>
#include<string>

using namespace std;

void GenerateKey(int vk, BOOL bExtended) {

    KEYBDINPUT  kb = {0};
    INPUT       Input = {0};

    /* Generate a "key down" */
    if (bExtended) { kb.dwFlags  = KEYEVENTF_EXTENDEDKEY; }
    kb.wVk  = vk;
    Input.type  = INPUT_KEYBOARD;
    Input.ki  = kb;
    SendInput(1, &Input, sizeof(Input));

    /* Generate a "key up" */
    ZeroMemory(&kb, sizeof(KEYBDINPUT));
    ZeroMemory(&Input, sizeof(INPUT));
    kb.dwFlags  =  KEYEVENTF_KEYUP;
    if (bExtended) { kb.dwFlags |= KEYEVENTF_EXTENDEDKEY; }
    kb.wVk = vk;
    Input.type = INPUT_KEYBOARD;
    Input.ki = kb;
    SendInput(1, &Input, sizeof(Input));

    return;
}    

int main() {

 SetConsoleTitle( "sendkeys" );
string sentence;
while (1){
  cin>>sentence;
  char letter;
  int track = 0; 

  while(sentence[track] != '\0') {

    cout<<sentence[track];
    letter = sentence[track];     
    GenerateKey(letter, FALSE);
    track++;    
}    
}    
}

Answer 1

This sort of approach is really complicated (you have to manage state of SHIFT, CONTROL, and ALT, convert special characters to ALT+0xyz combos) and if the user changes keyboard focus in the process, keys can go to the wrong window.

Using SendMessage(WM_SETTEXT) or SendMessage(EM_REPLACESEL) you could send a whole string at once to a particular window.