Changing opacity of GUI

[Klovis]

I need to be able to change the opacity of my gui with a slider, I honestly don't have a clue where to start. I don't have the time right now but if someone could give me example code and maybe explain it I would be very greatful. Thankyou!

[guinness]

Look at GUICtrlCreateSlider() and WinSetTrans() in the Help File.

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#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>

Global $hGUI, $hSlider, $iLabel, $iSlider

_Main()

Func _Main()
    $hGUI = GUICreate("Test", 500, 75)
    $iSlider = GUICtrlCreateSlider(10, 10, 480, 30)
    $hSlider = GUICtrlGetHandle(-1)
    GUICtrlSetLimit(-1, 100, 20) ; Set Limit to 20%.
    $iLabel = GUICtrlCreateLabel("", 10, 55, 200, 20)

    GUISetState(@SW_SHOW)
    GUIRegisterMsg($WM_HSCROLL, "WM_HSCROLL")
    WinSetTrans($hGUI, "", (GUICtrlRead($iSlider) & "%" / 100) * 255)

    While 1
        Switch GUIGetMsg()
            Case $GUI_EVENT_CLOSE
                Exit

        EndSwitch

    WEnd
EndFunc   ;==>_Main

Func WM_HSCROLL($hWnd, $iMsg, $iwParam, $ilParam)
    #forceref
    Local $iValue
    If $ilParam = $hSlider Then
        $iValue = GUICtrlRead($iSlider) & "%"
        GUICtrlSetData($iLabel, $iValue)
        WinSetTrans($hGUI, "", ($iValue / 100) * 255)
    EndIf
    Return "GUI_RUNDEFMSG"
EndFunc   ;==>WM_HSCROLL

[Klovis]

Thanks sooo much I keep running into this WM_HSCROLL It confuses me

[guinness]

Have a look here WM_HSCROLL Message for more details about capturing where the slider is, to note this is how I update the label with the percentage.

[smartee]

Look at this example, it comes packaged with the AutoIt installation, you can find it at %PROGRAMFILES%\AutoIt3\Examples\GUI\Advanced\AlphaBlend.au3

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#include <GDIPlus.au3>
#include <WinAPI.au3>
#include <WindowsConstants.au3>
#include <GuiConstantsEx.au3>

Opt("MustDeclareVars", 1)

; ===============================================================================================================================
; Description ...: Shows how to create an alpha blended form
; Author ........: Paul Campbell (PaulIA)
; Notes .........: The images used for this demo MUST be 32 bpp with alpha channel
; Credits .......: Thanks to lod3n for supplying links to the technical documentation that was necessary to build this demo
; ===============================================================================================================================

; ===============================================================================================================================
; Global constants
; ===============================================================================================================================
Global Const $AC_SRC_ALPHA      = 1

; ===============================================================================================================================
; Global variables
; ===============================================================================================================================
Global $hGUI1, $hGUI2, $iLabel1, $iLabel2, $iSlider, $hImage

; Create GUI
$hGUI1 = GUICreate("Alpha Blend", 400, 100)
$iLabel1 = GUICtrlCreateLabel ("Adjust slider to change opacity level: (0-255)", 84, 10, 380, 20)
$iSlider = GUICtrlCreateSlider(10, 32, 380, 40)
$iLabel2 = GUICtrlCreateLabel ("Drag the layered window around your desktop"   , 80, 74, 380, 20)
GUICtrlSetLimit($iSlider, 255, 0)
GUICtrlSetData ($iSlider, 255)
GUISetState()

; Create layered child window
$hGUI2 = GUICreate("Test", 250, 250, -1, -1, -1, $WS_EX_LAYERED, $hGUI1)

; Load layered image
_GDIPlus_Startup()
$hImage = _GDIPlus_ImageLoadFromFile(@ScriptDir & "\Images\Button.png")
;~ $hImage = _GDIPlus_ImageLoadFromFile(@ScriptDir & "\Images\Torus.png")
SetBitMap($hGUI2, $hImage, 255)
GUISetState()

; Register notification messages
GUIRegisterMsg($WM_HSCROLL  , "WM_HSCROLL"  )
GUIRegisterMsg($WM_NCHITTEST, "WM_NCHITTEST")

; Loop until user exits
do
until GUIGetMsg() =$GUI_EVENT_CLOSE

; Release resources
_GDIPlus_ImageDispose($hImage)
_GDIPlus_Shutdown()

; ===============================================================================================================================
; Handle the WM_HSCROLL notificaton so that we can change the opacity in real time
; ===============================================================================================================================
Func WM_HSCROLL($hWnd, $iMsg, $iwParam, $ilParam)
  SetBitMap($hGUI2, $hImage, GUICtrlRead($iSlider))
EndFunc

; ===============================================================================================================================
; Handle the WM_NCHITTEST for the layered window so it can be dragged by clicking anywhere on the image.
; ===============================================================================================================================
Func WM_NCHITTEST($hWnd, $iMsg, $iwParam, $ilParam)
  if ($hWnd = $hGUI2) and ($iMsg = $WM_NCHITTEST) then Return $HTCAPTION
EndFunc

; ===============================================================================================================================
; SetBitMap
; ===============================================================================================================================
Func SetBitmap($hGUI, $hImage, $iOpacity)
  Local $hScrDC, $hMemDC, $hBitmap, $hOld, $pSize, $tSize, $pSource, $tSource, $pBlend, $tBlend

  $hScrDC  = _WinAPI_GetDC(0)
  $hMemDC  = _WinAPI_CreateCompatibleDC($hScrDC)
  $hBitmap = _GDIPlus_BitmapCreateHBITMAPFromBitmap($hImage)
  $hOld    = _WinAPI_SelectObject($hMemDC, $hBitmap)
  $tSize   = DllStructCreate($tagSIZE)
  $pSize   = DllStructGetPtr($tSize  )
  DllStructSetData($tSize, "X", _GDIPlus_ImageGetWidth ($hImage))
  DllStructSetData($tSize, "Y", _GDIPlus_ImageGetHeight($hImage))
  $tSource = DllStructCreate($tagPOINT)
  $pSource = DllStructGetPtr($tSource)
  $tBlend  = DllStructCreate($tagBLENDFUNCTION)
  $pBlend  = DllStructGetPtr($tBlend)
  DllStructSetData($tBlend, "Alpha" , $iOpacity    )
  DllStructSetData($tBlend, "Format", $AC_SRC_ALPHA)
  _WinAPI_UpdateLayeredWindow($hGUI, $hScrDC, 0, $pSize, $hMemDC, $pSource, 0, $pBlend, $ULW_ALPHA)
  _WinAPI_ReleaseDC   (0, $hScrDC)
  _WinAPI_SelectObject($hMemDC, $hOld)
  _WinAPI_DeleteObject($hBitmap)
  _WinAPI_DeleteDC    ($hMemDC)
EndFunc