Windows virtual key codes

Question

How can I implement a function like std::string VirtualKeyCodeToStdString(UCHAR key) which returns virtual keys descriptions?

Example: input is VK_CAPITAL, return value is std::string("Caps Lock")

Answer 1

A simple way to convert the VK code to a text representation of the key is to:

1. Use MapVirtualKey to convert the VK code to a scan code.
2. Do a bit shift to convert that value into a long where bits 16-23 are the scan code
3. Use GetKeyNameText to obtain the name of the key.

For example:

WCHAR name[1024];
UINT scanCode = MapVirtualKeyW(VK_CAPITAL, MAPVK_VK_TO_VSC);
LONG lParamValue = (scanCode << 16);
int result = GetKeyNameTextW(lParamValue, name, 1024);
if (result > 0)
{
    std::wcout << name << endl; // Output: Caps Lock
}

If you're doing this in response to a WM_KEYDOWN or other message that passes the scan code in the LPARAM you can skip the first two steps, since those are just there to massage the VK code into a properly formatted input for GetKeyNameText. For more information about the function and the format of the first parameter to GetKeyNameText see the documentation at MSDN

Note: I used the W variant on the API calls, so you'd actually need to use a std::wstring to pass the key name, but you can change it easily to use the A version. Also, if you need to pass a keyboard layout to get the proper scan code, you can use MapVirtualKeyEx.