Strange input from WM_CHAR - WinAPI

Question

This is a continuation of my previous question: WinAPI: How to process keyboard input in custom edit control I felt i should put this in a different question as the nature of the question is a bit different.

So my program is receiving input now, but the input is a bit off. The best way to explain is to just show you the code and the result...

Here's the code that handles WM_CHAR:

    case WM_CHAR:
    {
        TCHAR inc;
        inc = MapVirtualKey(wParam, 2);

        for(short i = 0; i < sizeof(TCHAR); i++)
        {
            unsigned char* x = reinterpret_cast<unsigned char*>(&inc);
            printf("0x%.2X ", x[i]);
        }

        //InvalidateRect(t_hwnd, NULL, 0); // Repaint the window...

    }
    break;

The program is compiled as unicode so all function calls default to their unicode variants.

Here's the result of typing "asdf":

0x31 0x00 0x00 0x00 0x34 0x00 0x36 0x00
TCHAR is 2 bytes in size, so this comes out to "1\046"

Anyone know what the deal is here?

c-smile · Accepted Answer · 2011-04-30 23:09:19Z

1

MapVirtualKey accepts scan code for a key. But wParam in WM_CHAR is not a scan code - it is a char. You should use WM_KEYDOWN, wParam there is a scan code.

Links for you:

http://msdn.microsoft.com/en-us/library/ms646280(v=vs.85).aspx

http://msdn.microsoft.com/en-us/library/ms646276(v=vs.85).aspx

answered Apr 30, 2011 at 23:09

c-smile

27.6k8 gold badges66 silver badges91 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Gogeta70 Over a year ago

Actually, MapVirtualKey takes both scan codes and virtual key codes. It turns out i misread the documentation and that WM_CHAR returns a character code, not a virtual key code. Still, thanks for clarifying. ^_^

Collectives™ on Stack Overflow

Strange input from WM_CHAR - WinAPI

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related