vba key pause/resume - toggle - excel

Question

if the code - GetAsyncKeyState replaced with MsgBox, it's working fine however though there is no error, code doesn't work with GetAsyncKeyState.
or can command/toggle button will work with EXCEL VBA?
#If VBA7 Then
'declare virtual key event listener
Private Declare PtrSafe Function GetAsyncKeyState Lib "user32" _
(ByVal vKey As Long) As Integer
#Else
'declare virtual key event listener
Private Declare Function GetAsyncKeyState Lib "user32" _
(ByVal vKey As Long) As Integer
#End If
Private Const VK_RA = &H27
Sub Hide_Next()
Dim a As Range
Dim b As Range
Cells.EntireColumn.Hidden = True
Columns("a").EntireColumn.Hidden = False
If GetAsyncKeyState(vbKeyRight) Then
Application.Goto Reference:=Range("a1"), Scroll:=True
For Each a In Range("A2:A23").Cells
If a.Value = Empty Then
a.EntireRow.Hidden = True
End If
Next a
End If
If GetAsyncKeyState(vbKeyRight) Then
Columns("b").EntireColumn.Hidden = False
For Each b In Range("B2:B23").Cells
If b.Value <> Empty Then
b.EntireRow.Hidden = False
End If
Next b
End If
If GetAsyncKeyState(VK_RA) Then
Cells.EntireColumn.Hidden = False
End If
End Sub
Working Code, trying to replace MagBox with Keypress:
Sub Hide_Next()
Dim a As Range
Dim b As Range
Cells.EntireColumn.Hidden = True
Columns("a").EntireColumn.Hidden = False
MsgBox "Pause-A"
Application.Goto Reference:=Range("a1"), Scroll:=True
For Each a In Range("A2:A23").Cells
If a.Value = Empty Then
a.EntireRow.Hidden = True
End If
Next a
MsgBox "Pause-B"
Columns("b").EntireColumn.Hidden = False
For Each b In Range("B2:B23").Cells
If b.Value <> Empty Then
b.EntireRow.Hidden = False
End If
Next b
'and so on for the next column ...
End Sub
Example:

Answer 1

There's some strange things happening in your code.
The way this is written is that you would have to be pressing the right arrow key at the exact moment this subroutine is run. That's not preposterous or anything, but you don't state in your question what your expectation of this code is.
You check 3 times if that right key is being pressed and between each check you do some very slow front/ui actions like hiding rows and unhiding columns. If the user takes their finger off the right arrow key while excel is bopping around making changes the next block will not execute.
You check to see if the right arrow is pressed using both vbKeyRight and VK_RA constant. I'm not expert here but it DOES seem like both of those should return &H27... I would stick to one or the other though for debugging.
Rewriting:
#If VBA7 Then
'declare virtual key event listener
Private Declare PtrSafe Function GetAsyncKeyState Lib "user32" _
(ByVal vKey As Long) As Integer
#Else
'declare virtual key event listener
Private Declare Function GetAsyncKeyState Lib "user32" _
(ByVal vKey As Long) As Integer
#End If
Private Const VK_RA = &H27
Sub Hide_Next()
Dim a As Range
Dim rightKeyDown As Boolean
'Check if the right arrow key is being pressed before interacting with excel's slow UI.
If GetAsyncKeyState(VK_RA) Then
rightKeyDown = True
End If
'hide all the columns, except column A before doing anything
Cells.EntireColumn.Hidden = True
Columns("a").EntireColumn.Hidden = False
'Let's see if that right key was down
If rightKeyDown Then
Application.Goto Reference:=Range("a1"), Scroll:=True
For Each a In Range("A2:A23").Cells
If a.Value = "" AND a.Offset(,1).Value = "" Then
a.EntireRow.Hidden = True
End If
Next a
Cells.EntireColumn.Hidden = False
End If
End Sub
You also ask about a toggle button. It's not clear what your intentions are though (what is being toggled amongst these multiple steps?). A toggle button is an option though.