SendInput on c++ doesn't take Ctrl and Shift in account

Question

I'm trying to send a CTRL+SHIFT+END key stroke to a control, in a C++ application written with Embarcadero. I'm using the code below:

tagINPUT ip;
ip.type = INPUT_KEYBOARD;
ip.ki.wScan = 0;
ip.ki.time = 0;
ip.ki.dwExtraInfo = 0;

// Appui sur Ctrl
ip.ki.wVk = VK_CONTROL;
ip.ki.dwFlags = 0;
SendInput(1, &ip, sizeof(INPUT));

// Appui sur Shift
ip.ki.wVk = VK_SHIFT;
ip.ki.dwFlags = 0;
SendInput(1, &ip, sizeof(INPUT));

// Appui sur End
ip.ki.wVk = VK_END;
ip.ki.dwFlags = 0;
SendInput(1, &ip, sizeof(INPUT));

Application->ProcessMessages();

// Relacher End
ip.ki.wVk = VK_END;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
SendInput(1, &ip, sizeof(INPUT));

// Relacher Shift
ip.ki.wVk = VK_SHIFT;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
SendInput(1, &ip, sizeof(INPUT));

// Relacher Ctrl
ip.ki.wVk = VK_CONTROL;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
SendInput(1, &ip, sizeof(INPUT));

However, it appears to be working like if there was no action on the CTRL and SHIFT keys.

What am I missing ?

sendinput is not part of the standard c++, you should include more tags to your question, if you leave it like this you should include the code to that sendinput function, but I am guessing that you don´t have it, not everyone that uses c++ uses Embarcadero. — exs, Jul 05 '17 at 11:39
To be honest, I'm using the SendInput that was coming from theproject, enclosed in a win32.h file. This was done by someone else that is no longer in my company, so I cannot give any accurate idea of what it does. — C. MARIN, Jul 05 '17 at 11:48
Ok, this I got it. Now, why does it synthesize keystrokes as if the Ctrl and Shift were not hit, despite the SendInput I wrote in the code included in my question ? — C. MARIN, Jul 05 '17 at 12:14
Look for other examples here on SO for how to do this properly. I know there are some, but I don't have time to do your search for you right now. Search for `SendInput`. — 500 - Internal Server Error, Jul 05 '17 at 13:51
You should not do multiple `SendInput()` calls but instead pass an array with all the input you want to send in a **single** `SendInput()` call. — zett42, Jul 05 '17 at 14:03
I will try it, I thought about it. However some other bugs are keeping me away from that solution. Tomorrow is another day. — C. MARIN, Jul 05 '17 at 14:11
It's really important that you put all the events in an array and make one call to SendInput — David Heffernan, Jul 05 '17 at 16:45
Does important mean mandatory ? I mean: could that be the actual reason for it does not work ? Kinda odd behaviour for SendInput... — C. MARIN, Jul 06 '17 at 08:19
You can do it wrong if you want. The documentation explains the consequences of doing it wrong. — David Heffernan, Jul 06 '17 at 18:13
Well, I tried using an array of tagINPUT and one single SendInput, and the result is exactly the same as previously: the form reacts like if only the END key was hit. — C. MARIN, Jul 19 '17 at 13:51

score 4 · Answer 1 · edited Jul 28 '22 at 21:23

4

The problem is, that the VK_END key is an extended key. So you should declare this in the flags:

eip.ki.dwFlags = 0;
ip.ki.wVk = VK_END;
ip.ki.dwFlags = 0;
ip.ki.dwFlags = ip.ki.dwFlags | 1;
SendInput(1, &ip, sizeof(INPUT));

Application->ProcessMessages();

// Relacher End
ip.ki.wVk = VK_END;
ip.ki.dwFlags = KEYEVENTF_KEYUP;
ip.ki.dwFlags = ip.ki.dwFlags | 1;
SendInput(1, &ip, sizeof(INPUT));

Note that I used 1 for setting the flag as I don't know if you have a constant defined in your C++, but assume there is a constant someplace.

edited Jul 28 '22 at 21:23

HerrJoebob

2,264
16
25

answered Nov 16 '17 at 14:56

iamjoosy

3,299
20
30

Thanks a lot, I bet this is exactly the answer I needed :) I'll try it out quite soon and will tell wether it works or not (it surely well, I think). – C. MARIN Nov 17 '17 at 15:38

score 0 · Answer 2 · answered Jul 28 '22 at 20:37

Just add KEYEVENTF_EXTENDEDKEY flag to dwFlags

input.ki.dwFlags |= KEYEVENTF_EXTENDEDKEY;

Unfortunately, Win32 doesn't provide any way to determine if a key is extended. Here I just used a vector

    extended_keys << VK_INSERT;
    extended_keys << VK_DELETE;
    extended_keys << VK_HOME;
    extended_keys << VK_END;
    extended_keys << VK_PRIOR;
    extended_keys << VK_NEXT;
    extended_keys << VK_LEFT;
    extended_keys << VK_UP;
    extended_keys << VK_DOWN;
    extended_keys << VK_RIGHT;

and checked if it's inside the list add the flag

SendInput on c++ doesn't take Ctrl and Shift in account

2 Answers2

Linked