get keydown on application/form load in vb.net

Question

I want to able to hold a key down while the application is loading and depending on which is being held down a certain form is shown.

For example holding down shift and the opening itunes opens a little dialog allowing you set the library(or something)

I can check whether the shift/Ctrl/Alt are being held down but i'd prefer to use the letters/digits.

Such as hold 1 down to open Form1 and hold 2 down to open form 2.

Answer 1

If you are using WPF, you can use the Keyboard.GetKeyStates method to determine the state of an individual Key. For example

If KeyBoard.GetKeyStates(Key.D1) = KeyStates.Down Then
  ' Open Form1
End If

More Info:

• http://msdn.microsoft.com/en-us/library/system.windows.input.keyboard.getkeystates.aspx

EDIT

For WinForms the solution is a bit harder. There is no exposed method that I know of which will give you the exposed state in a Key enum. Instead you'll have to PInvoke into the Win32 GetKeyState method.

<DllImport("user32.dll", CharSet:=CharSet.Auto, ExactSpelling:=True)> _
Public Shared Function GetKeyState(ByVal keyCode As Integer) As Short
End Function

For most keys the result should be directly convertible from a Key value.

If NativeMethods.GetKeyState(CInt(Key.D1)) < 0 Then
  ' 1 is held down
End If

Answer 2

If you're wanting to do this on traditional winforms, you can check out this article:

http://www.switchonthecode.com/tutorials/winforms-accessing-mouse-and-keyboard-state

About half-way down there's an abstract Keyboard class that uses a system call to get key states. You might want to give it a try.

EDIT: Here's that class converted to VB.NET. I haven't tested it so there might be some errors. Let me know.

Imports System
Imports System.Windows.Forms
Imports System.Runtime.InteropServices

Public MustInherit Class Keyboard

    <Flags()>
    Private Enum KeyStates
        None = 0
        Down = 1
        Toggled = 2
    End Enum

    <DllImport("user32.dll", CharSet:=CharSet.Auto, ExactSpelling:=True)>
    Private Shared Function GetKeyState(ByVal keyCode As Integer) As Short
    End Function

    Private Shared Function GetKeyState(ByVal key As Keys) As KeyStates
        Dim state = KeyStates.None

        Dim retVal = GetKeyState(CType(key, Integer))

        ' if the high-order bit is 1, the key is down
        ' otherwise, it is up
        If retVal And &H8000 = &H8000 Then
            state = state Or KeyStates.Down
        End If

        ' If the low-order bit is 1, the key is toggled.
        If retVal And 1 = 1 Then
            state = state Or KeyStates.Toggled
        End If

        Return state
    End Function

    Public Shared Function IsKeyDown(ByVal key As Keys) As Boolean
        Return KeyStates.Down = (GetKeyState(key) And KeyStates.Down)
    End Function

    Public Shared Function IsKeyToggled(ByVal key As Keys) As Boolean
        Return KeyStates.Toggled = (GetKeyState(key) And KeyStates.Toggled)
    End Function

End Class

So once you add this class to your project, you can do something like this:

' See if the 1 button is being held down
If Keyboard.IsKeyDown(Keys.D1) Then
    ' Do the form showing stuff here
EndIf