RAWKEYBOARD structure (winuser.h)

  • Article

Contains information about the state of the keyboard.

Syntax

typedef struct tagRAWKEYBOARD {
  USHORT MakeCode;
  USHORT Flags;
  USHORT Reserved;
  USHORT VKey;
  UINT   Message;
  ULONG  ExtraInformation;
} RAWKEYBOARD, *PRAWKEYBOARD, *LPRAWKEYBOARD;

Members

MakeCode

Type: USHORT

Specifies the scan code associated with a key press. See Remarks.

Flags

Type: USHORT

Flags for scan code information. It can be one or more of the following:

Value Meaning
RI_KEY_MAKE 0 The key is down.
RI_KEY_BREAK 1 The key is up.
RI_KEY_E0 2 The scan code has the E0 prefix.
RI_KEY_E1 4 The scan code has the E1 prefix.

Reserved

Type: USHORT

Reserved; must be zero.

VKey

Type: USHORT

The corresponding legacy virtual-key code.

Message

Type: UINT

The corresponding legacy keyboard window message, for example WM_KEYDOWN, WM_SYSKEYDOWN, and so forth.

ExtraInformation

Type: ULONG

The device-specific additional information for the event.

Remarks

KEYBOARD_OVERRUN_MAKE_CODE is a special MakeCode value sent when an invalid or unrecognizable combination of keys is pressed or the number of keys pressed exceeds the limit for this keyboard.

case WM_INPUT:
{
    UINT dwSize = sizeof(RAWINPUT);
    static BYTE lpb[sizeof(RAWINPUT)];

    GetRawInputData((HRAWINPUT)lParam, RID_INPUT, lpb, &dwSize, sizeof(RAWINPUTHEADER));

    RAWINPUT* raw = (RAWINPUT*)lpb;

    if (raw->header.dwType == RIM_TYPEKEYBOARD)
    {
        RAWKEYBOARD& keyboard = raw->data.keyboard;
        WORD scanCode = 0;
        BOOL keyUp = keyboard.Flags & RI_KEY_BREAK;

        // Ignore key overrun state and keys not mapped to any virtual key code
        if (keyboard.MakeCode == KEYBOARD_OVERRUN_MAKE_CODE || keyboard.VKey >= UCHAR_MAX)
            return 0;

        if (keyboard.MakeCode)
        {
            // Compose the full scan code value with its extended byte
            scanCode = MAKEWORD(keyboard.MakeCode & 0x7f, ((keyboard.Flags & RI_KEY_E0) ? 0xe0 : ((keyboard.Flags & RI_KEY_E1) ? 0xe1 : 0x00)));
        }
        else
        {
            // Scan code value may be empty for some buttons (for example multimedia buttons)
            // Try to get the scan code from the virtual key code
            scanCode = LOWORD(MapVirtualKey(keyboard.VKey, MAPVK_VK_TO_VSC_EX));
        }

        // Get the key name for debug output
        TCHAR keyNameBuffer[MAX_PATH] = {};
        GetKeyNameText((LONG)MAKELPARAM(0, (HIBYTE(scanCode) ? KF_EXTENDED : 0x00) | LOBYTE(scanCode)), keyNameBuffer, MAX_PATH);

        // Debug output
        TCHAR printBuffer[MAX_PATH] = {};
        StringCchPrintf(printBuffer, MAX_PATH, TEXT("Keyboard: scanCode=%04x keyName=%s\r\n"), scanCode, keyNameBuffer);
        OutputDebugString(printBuffer);
    }
    ...

    return 0;
}

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header winuser.h (include Windows.h)

See also