Making a Frameless Userform Transparent

Question

I have made it so that a number of my userforms no longer display their title bars. Here is the code I had to add to make that happen:

Option Explicit

#If VBA7 Then
    Public Declare PtrSafe Function FindWindow Lib "user32" _
                Alias "FindWindowA" _
               (ByVal lpClassName As String, _
                ByVal lpWindowName As String) As Long


    Public Declare PtrSafe Function GetWindowLong Lib "user32" _
                Alias "GetWindowLongA" _
               (ByVal hWnd As Long, _
                ByVal nIndex As Long) As Long


    Public Declare PtrSafe Function SetWindowLong Lib "user32" _
                Alias "SetWindowLongA" _
               (ByVal hWnd As Long, _
                ByVal nIndex As Long, _
                ByVal dwNewLong As Long) As Long

    Public Declare PtrSafe Function DrawMenuBar Lib "user32" _
               (ByVal hWnd As Long) As Long

    Public Declare PtrSafe Function SetLayeredWindowAttributes Lib "user32" ( _
                ByVal hWnd As Long, _
                ByVal crKey As Long, _
                ByVal bAlpha As Byte, _
                ByVal dwFlags As Long) As Long
#Else
    Public Declare Function FindWindow Lib "user32" _
                Alias "FindWindowA" _
               (ByVal lpClassName As String, _
                ByVal lpWindowName As String) As Long


    Public Declare Function GetWindowLong Lib "user32" _
                Alias "GetWindowLongA" _
               (ByVal hWnd As Long, _
                ByVal nIndex As Long) As Long


    Public Declare Function SetWindowLong Lib "user32" _
                Alias "SetWindowLongA" _
               (ByVal hWnd As Long, _
                ByVal nIndex As Long, _
                ByVal dwNewLong As Long) As Long


    Public Declare Function DrawMenuBar Lib "user32" _
               (ByVal hWnd As Long) As Long

    Public Declare Function SetLayeredWindowAttributes Lib "user32" ( _
                ByVal hWnd As Long, _
                ByVal crKey As Long, _
                ByVal bAlpha As Byte, _
                ByVal dwFlags As Long) As Long
#End If

Sub HideBar(frm As Object)
Dim Style As Long, Menu As Long, hWndForm As Long

hWndForm = FindWindow("ThunderDFrame", frm.Caption)
Style = GetWindowLong(hWndForm, &HFFF0)
Style = Style And Not &HC00000
SetWindowLong hWndForm, &HFFF0, Style
DrawMenuBar hWndForm

End Sub

I admit I don't understand what 90% of it does, but it works. Now I want to add the option to make the background of the userform transparent. Does anyone know if there will be any conflict between my existing code and the code i want to add?

Declare Function SetLayeredWindowAttributes Lib "user32" ( _
                ByVal hWnd As Long, _
                ByVal crKey As Long, _
                ByVal bAlpha As Byte, _
                ByVal dwFlags As Long) As Long

'Constants for title bar
Private Const GWL_STYLE As Long = (-16)           'The offset of a window's style
Private Const GWL_EXSTYLE As Long = (-20)         'The offset of a window's extended style
Private Const WS_CAPTION As Long = &HC00000       'Style to add a titlebar
Private Const WS_EX_DLGMODALFRAME As Long = &H1   'Controls if the window has an icon

'Constants for transparency
Private Const WS_EX_LAYERED = &H80000
Private Const LWA_COLORKEY = &H1                  'Chroma key for fading a certain color on your Form
Private Const LWA_ALPHA = &H2                     'Only needed if you want to fade the entire userform

Private Sub UserForm_Activate()
HideTitleBarAndBorder Me 'hide the titlebar and border
MakeUserFormTransparent Me 'make certain color transparent
End Sub

Sub MakeUserFormTransparent(frm As Object, Optional Color As Variant)
'set transparencies on userform
Dim formhandle As Long
Dim bytOpacity As Byte

formhandle = FindWindow(vbNullString, Me.Caption)
If IsMissing(Color) Then Color = vbWhite 'default to vbwhite
bytOpacity = 100 ' variable keeping opacity setting

SetWindowLong formhandle, GWL_EXSTYLE, GetWindowLong(formhandle, GWL_EXSTYLE) Or WS_EX_LAYERED
'The following line makes only a certain color transparent so the
' background of the form and any object whose BackColor you've set to match
' vbColor (default vbWhite) will be transparent.
    Me.BackColor = Color
    SetLayeredWindowAttributes formhandle, Color, bytOpacity, LWA_COLORKEY
End Sub

Answer 1

This is because of the way that React internally handles its events queue. That first update is eagerly computed. From react-dom.development.js dispatchAction function:

if (fiber.lanes === NoLanes && (alternate === null || alternate.lanes === NoLanes)) {
  // The queue is currently empty, which means we can eagerly compute the
  // next state before entering the render phase. If the new state is the
  // same as the current state, we may be able to bail out entirely.

  ...

Ideally, if you want to use any functionality after updating a state you should use the useEffect hook as is indicated by some React console errors:

console.error(
        "State updates from the useState() and useReducer() Hooks don't support the " +
          'second callback argument. To execute a side effect after ' +
          'rendering, declare it in the component body with useEffect().',
      );

So, if you want your code to execute always in the same order, you should change your code and include a useEffect hook