Can't convert from virtual key code to unicode

Question

I need to inject text into directinput applications. I'm using SendInput, but using virtual key codes doesn't work with directinput, so I need to use Unicode. Now, the keys I wan't to inject are registered on a file as virtual key codes, and i need to convert them to Unicode in real time.

return1 = ToUnicode(vk, MapVirtualKey(vk, MAPVK_VK_TO_VSC), NULL, buffer, 1, 0);

This is my code string. vk is the virtual key in a int, and buffer is a wchar_t array large 1 unit. I couldn't use just a simple wchar_t because it didn't work with ToUnicode. However, this function just returns 0 everytime, thus meaning the function couldn't translate the key. For the record, i'm using standard keys, such as "wasd", no special characters. If anyone can make out why this happens, I would really like some help.

Thanks for the consideration!

EDIT: also, would it be convenient to just fight my laziness and write some old switch and break to convert the values? eg.

wchar_t unicode; switch (vk) case '0x30': unicode = '48'; //ecc...

It would help if you gave an exact case of a failure...including the actual values going in. For instance say what vk is, and the result of MapVirtualVk(vk, 0). Also, the second parameter to MapVirtualKey has constants defined for it...so MAPVK_VK_TO_VSC is clearer than just saying 0. — HostileFork says dont trust SE
– HostileFork says dont trust SE, Commented Aug 6, 2014 at 1:28
Editing the question, anyway, as i wrote, this happens with every key. The result of MapVirtualVk(vk, 0), as I think it should be, depend on the key. for example "3" gives 44, "a" gives 3030. — Alex
– Alex, Commented Aug 6, 2014 at 1:31

HostileFork says dont trust SE · Accepted Answer · 2014-08-06 02:50:23Z

1

It says that the "keys" array is optional, but unless I pass in a keys I get a zero result too. Maybe they just mean you have the option of having it work or not?

std::vector<BYTE> keys(256, 0); int sc = MapVirtualKey(vk, MAPVK_VK_TO_VSC); return1 = ToUnicode(vk, sc, keys.data(), buffer, 1, 0);

So try that (or &keys[0] instead of keys.data() if you're not using C++11).

edited Aug 6, 2014 at 2:50

answered Aug 6, 2014 at 2:00

HostileFork says dont trust SE

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4 Comments

Alex Over a year ago

Thanks! Now ToUnicode returns the right values, even though SendInput with unicode flag on, wVk = 0 and Input.ki.wScan=buffer[0] still prints nothing :(

Alex Over a year ago

One little answer, if you know it thanks, if not thanks anyway. Can i just put in wScan the codes resulting from ToUnicode (eg. for "a", 97), or do I have to process them someway?

HostileFork says dont trust SE Over a year ago

@Alex Faking input is a dodgy art in the first place, and I don't know much about DirectInput. So it really is best to open a new question, and give very precise test cases that don't work--so other people can reproduce it.

Alex Over a year ago

Yes,already opened another question, and already solved the problem 10 minutes after. I didn't have to use Unicode, just hardware scan codes. Thanks Anyway!

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