DirectX:DirectInput:Tutorials:VB:DX7:Keyboard Handling
DirectInput is the component of DirectX that gives you direct access to the current state of the keyboard (among other devices). This is obviously quite useful for game programming purposes and so I will outline its use here.
Dim dx As New DirectX7
Dim di As DirectInput
Dim diDEV As DirectInputDevice
Set di = dx.DirectInputCreate()
Set diDEV = di.CreateDevice("GUID_SysKeyboard")
diDEV.SetCommonDataFormat DIFORMAT_KEYBOARD diDEV.SetCooperativeLevel Me.hWnd, DISCL_BACKGROUND Or DISCL_NONEXCLUSIVE diDEV.Acquire
As with DirectDraw, we have to create an instance of the DirectX7 object and use it to define a DirectInput object, di. We then need to set the direct input device to the one in which we are interested, in this case the keyboard. So, we call the di.CreateDevice method and request it returns the system keyboard object.
Next we have to set the data format of the device to the keyboard data format. We do this with the diDEV.SetCommonDataFormat. We could also use this to set the data format to Joy1, Joy2, or the mouse.
Just like DirectDraw, we must set the cooperative level. We pass the handle to the window for which we would like to receive keyboard input, if this is the form in which the code resides we can pass Me.hWnd. DISCL_BACKGROUND and DISCL_NONEXCLUSIVE allows other programs access to keystrokes, and give us access to all keystrokes.
Now that we've set up the device which we'd like to use, we have to acquire it using the diDEV.Acquire method.
Dim diState As DIKEYBOARDSTATE
Dim i As Integer
Public aKeys(211) As Boolean
diDEV.GetDeviceStateKeyboard diState
For i = 1 To 211
If diState.Key(i) <> 0 Then
aKeys(i) = True
Else
aKeys(i) = False
End If
Next
Everything is setup, now we can reap what we have sown (no, I'm not suggesting you go plant your keyboard in your garden in order to cultivate input). diState is an object that will contain the states of all the keys on the keyboard, and we can tap into this using an array and a loop. Each key on the keyboard corresponds to an integer value between 0 and 211. If we then make an array with 212 members we can keep track of which keys are active and when. Use the diDEV.GetDeviceStateKeyboard method to fill the diState variable, and then extract the data from this into our array aKeys using a for loop.
Click here for sample source code demonstrating DirectInput keyboard handling in action.
This may be useful:
Private Function KeyName(Key As Byte) As String
Select Case Key
Case DIK_ESCAPE
KeyName = "ESCAPE"
Case DIK_1
KeyName = "1"
Case DIK_2
KeyName = "2"
Case DIK_3
KeyName = "3"
Case DIK_4
KeyName = "4"
Case DIK_5
KeyName = "5"
Case DIK_6
KeyName = "6"
Case DIK_7
KeyName = "7"
Case DIK_8
KeyName = "8"
Case DIK_9
KeyName = "9"
Case DIK_0
KeyName = "0"
Case DIK_MINUS
KeyName = "-"
Case DIK_EQUALS
KeyName = "="
Case DIK_BACK
KeyName = "BACKSPACE"
Case DIK_TAB
KeyName = "TAB"
Case DIK_Q
KeyName = "Q"
Case DIK_W
KeyName = "W"
Case DIK_E
KeyName = "E"
Case DIK_R
KeyName = "R"
Case DIK_T
KeyName = "T"
Case DIK_Y
KeyName = "Y"
Case DIK_U
KeyName = "U"
Case DIK_I
KeyName = "I"
Case DIK_O
KeyName = "O"
Case DIK_P
KeyName = "P"
Case DIK_LBRACKET
KeyName = "["
Case DIK_RBRACKET
KeyName = "]"
Case DIK_RETURN
KeyName = "RETURN"
Case DIK_LCONTROL
KeyName = "LEFT CONTROL"
Case DIK_A
KeyName = "A"
Case DIK_S
KeyName = "S"
Case DIK_D
KeyName = "D"
Case DIK_F
KeyName = "F"
Case DIK_G
KeyName = "G"
Case DIK_H
KeyName = "H"
Case DIK_J
KeyName = "J"
Case DIK_K
KeyName = "K"
Case DIK_L
KeyName = "L"
Case DIK_SEMICOLON
KeyName = ";"
Case DIK_APOSTROPHE
KeyName = "'"
Case DIK_GRAVE
KeyName = "`"
Case DIK_LSHIFT
KeyName = "LEFT SHIFT"
Case DIK_BACKSLASH
KeyName = "\"
Case DIK_Z
KeyName = "Z"
Case DIK_X
KeyName = "X"
Case DIK_C
KeyName = "C"
Case DIK_V
KeyName = "V"
Case DIK_B
KeyName = "B"
Case DIK_N
KeyName = "N"
Case DIK_M
KeyName = "M"
Case DIK_COMMA
KeyName = ","
Case DIK_PERIOD
KeyName = "."
Case DIK_SLASH
KeyName = "/"
Case DIK_RSHIFT
KeyName = "RIGHT SHIFT"
Case DIK_MULTIPLY
KeyName = "NUMPAD MULTIPLY"
Case DIK_LMENU
KeyName = "LEFT ALT"
Case DIK_SPACE
KeyName = "SPACE"
Case DIK_CAPITAL
KeyName = "CAPS LOCK"
Case DIK_F1
KeyName = "F1"
Case DIK_F2
KeyName = "F2"
Case DIK_F3
KeyName = "F3"
Case DIK_F4
KeyName = "F4"
Case DIK_F5
KeyName = "F5"
Case DIK_F6
KeyName = "F6"
Case DIK_F7
KeyName = "F7"
Case DIK_F8
KeyName = "F8"
Case DIK_F9
KeyName = "F9"
Case DIK_F10
KeyName = "F10"
Case DIK_NUMLOCK
KeyName = "NUM LOCK"
Case DIK_SCROLL
KeyName = "SCROLL LOCK"
Case DIK_NUMPAD7
KeyName = "NUMPAD 7"
Case DIK_NUMPAD8
KeyName = "NUMPAD 8"
Case DIK_NUMPAD9
KeyName = "NUMPAD 9"
Case DIK_SUBTRACT
KeyName = "NUMPAD SUBTRACT"
Case DIK_NUMPAD4
KeyName = "NUMPAD 4"
Case DIK_NUMPAD5
KeyName = "NUMPAD 5"
Case DIK_NUMPAD6
KeyName = "NUMPAD 6"
Case DIK_ADD
KeyName = "NUMPAD ADD"
Case DIK_NUMPAD1
KeyName = "NUMPAD 1"
Case DIK_NUMPAD2
KeyName = "NUMPAD 2"
Case DIK_NUMPAD3
KeyName = "NUMPAD 3"
Case DIK_NUMPAD0
KeyName = "NUMPAD 0"
Case DIK_DECIMAL
KeyName = "NUMPAD DECIMAL"
Case DIK_F11
KeyName = "F11"
Case DIK_F12
KeyName = "F12"
Case DIK_F13
KeyName = "F13"
Case DIK_F14
KeyName = "F14"
Case DIK_F15
KeyName = "F15"
Case DIK_NUMPADENTER
KeyName = "NUMPAD ENTER"
Case DIK_RCONTROL
KeyName = "RIGHT CONTROL"
Case DIK_NUMPADCOMMA
KeyName = "NUMPAD ,"
Case DIK_DIVIDE
KeyName = "/"
Case DIK_SYSRQ
KeyName = "PRINT SCREEN"
Case DIK_RMENU
KeyName = "RIGHT ALT"
Case DIK_HOME
KeyName = "HOME"
Case DIK_UP
KeyName = "UP"
Case DIK_PRIOR
KeyName = "PAGE UP"
Case DIK_LEFT
KeyName = "LEFT"
Case DIK_RIGHT
KeyName = "RIGHT"
Case DIK_END
KeyName = "END"
Case DIK_DOWN
KeyName = "DOWN"
Case DIK_NEXT
KeyName = "PAGE DOWN"
Case DIK_INSERT
KeyName = "INSERT"
Case DIK_DELETE
KeyName = "DELETE"
Case DIK_LWIN
KeyName = "LEFT WINDOWS"
Case DIK_RWIN
KeyName = "RIGHT WINDOWS"
Case DIK_APPS
KeyName = "APPLICATION"
Case DIK_PAUSE
KeyName = "PAUSE"
End Select
End Function
