SendInput strings?

Question

So I've been trying to make a program that sends a string of keystrokes over to the currently open window and whenever I run the code, it doesn't send whatever I want it to send it sends something completely different(i.e sending bob comes up as 22 or 2/2)

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


 int SendKeys(const std::string &msg);

int main() {
 Sleep(5);
 while(true) {
      Sleep(500);
      SendKeys("iajsdasdkjahdjkasd");
}
      std::cin.get(); 
return 0;
}


int SendKeys(const std::string & msg)
{
   std::vector<INPUT> bob(msg.size());

 for(unsigned int i = 0; i < msg.size(); ++i)
 {
  bob[i].type = INPUT_KEYBOARD;
  bob[i].ki.wVk = msg[i]; 
  std::cout << bob[i].ki.wVk << std::endl;
  auto key = SendInput(1, &bob[i], sizeof(INPUT) /* *bob.size() */);


 }
    return 0;  
 }

(forgive the horrible formatting)

Well, why did you write `sizeof(INPUT)` instead of `bob.size()`? — Lightness Races in Orbit, Jul 09 '16 at 16:27
because I was troubleshooting, when using bob.size() I got again, different text. — PavelF, Jul 09 '16 at 16:29
@LightnessRacesinOrbit actually no, sorry, when using bob.size() it didn't send text input at all. — PavelF, Jul 09 '16 at 16:30
but when using sizeof(INPUT) I got 2/2 sent as key input instead of bob (when using SendKeys("bob")) — PavelF, Jul 09 '16 at 16:32
What is the use of the vector `bob`? You still send one letter at a time so only need one single `INPUT` structure. — Some programmer dude, Jul 09 '16 at 16:38
@JoachimPileborg sorry to bother, but how would I send something like shift? — PavelF, Jul 09 '16 at 17:39
Well `sizeof(INPUT)` is certainly wrong. Programming by guessing doesn't work! — Lightness Races in Orbit, Jul 09 '16 at 19:08
If you are sending one key at a time, in a loop, then use `keybd_event`. Use `SendInput` for sending multiple keys. For example `SendInput(10, ten_keys, sizeof(INPUT))` — Barmak Shemirani, Jul 10 '16 at 02:32

score 2 · Accepted Answer · answered Jul 09 '16 at 16:33

The virtual key codes does not generally correspond to the ASCII alphabet.

If you read e.g. this MSDN reference for virtual key-codes you will see that e.g. lower-case 'a' (which has ASCII value 0x61) corresponds to VK_NUMPAD1 which is the 1 key on the numeric keyboard.

The upper-case ASCII letters do correspond to the correct virtual key codes, so you need to make all letters upper-case when assigning to bob[i].ki.wVk. For all other symbols and characters you need to translate the character to the virtual key code.

SendInput strings?

1 Answers1