No, I'm not. What I'm really saying is that you need a memory DC containing the source image, and then alphablit it to the form, controlling the transparency level via the SourceConstantAlpha member of the BlendFunction UDT.
I don't have the time to knock together a specific example of this, but here is some (ropey) code that fades a form in and out on loading an unloading. You shoud be able to adapt to your needs. The example just needs a form, and the following code:
[tt]
Option Explicit
Const AC_SRC_OVER = &H0
Private Type BLENDFUNCTION
BlendOp As Byte
BlendFlags As Byte
SourceConstantAlpha As Byte
AlphaFormat As Byte
End Type
Private Declare Function AlphaBlend Lib "msimg32.dll" (ByVal hdc As Long, ByVal lInt As Long, ByVal lInt As Long, ByVal lInt As Long, ByVal lInt As Long, ByVal hdc As Long, ByVal lInt As Long, ByVal lInt As Long, ByVal lInt As Long, ByVal lInt As Long, ByVal BLENDFUNCT As Long) As Long
Private Declare Sub RtlMoveMemory Lib "kernel32.dll" (Destination As Any, Source As Any, ByVal Length As Long)
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetWindowRect Lib "user32" (ByVal hwnd As Long, lpRect As RECT) As Long
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Const SRCCOPY = &HCC0020
Private Function Fader(Optional Direction As Long)
Dim ScreenCopyDC As Long
Dim myDC As Long
Dim myBMP As Long
Dim oldBMP As Long
Dim myrect As RECT
Dim BF As BLENDFUNCTION
Dim lBF As Long
Dim fade As Long
GetWindowRect Me.hwnd, myrect
If Direction = 0 Then
Me.Hide
Else
Me.Show
End If
DoEvents
' Snapshot the either the form or the desktop under the form, depending on whether
' fade in or fade out is required
myDC = GetWindowDC(GetDesktopWindow())
ScreenCopyDC = CreateCompatibleDC(myDC)
myBMP = CreateCompatibleBitmap(myDC, myrect.Right - myrect.Left, myrect.Bottom - myrect.Top) ' Me.ScaleWidth, Me.ScaleHeight)
oldBMP = SelectObject(ScreenCopyDC, myBMP)
BitBlt ScreenCopyDC, 0, 0, myrect.Right - myrect.Left + 100, myrect.Bottom - myrect.Top + 100, myDC, myrect.Left, myrect.Top, SRCCOPY
If Direction = 0 Then
Me.Show
Else
Me.Hide
End If
DoEvents
For fade = 0 To 127 ' Step 4 : add the step back in if you want to speed things up
With BF
.BlendOp = AC_SRC_OVER
.BlendFlags = 0
.SourceConstantAlpha = fade
.AlphaFormat = 0
End With
RtlMoveMemory lBF, BF, 4
AlphaBlend myDC, myrect.Left, myrect.Top, myrect.Right - myrect.Left, myrect.Bottom - myrect.Top, ScreenCopyDC, 0, 0, myrect.Right - myrect.Left, myrect.Bottom - myrect.Top, lBF
Next
'Clean up
SelectObject ScreenCopyDC, oldBMP
DeleteObject myBMP
ReleaseDC GetDesktopWindow(), myDC
DeleteDC myDC
DeleteDC ScreenCopyDC
If Direction = 0 Then
Me.Hide
Else
Me.Show
End If
End Function
Private Sub Form_Load()
Fader 1
End Sub
Private Sub Form_Unload(Cancel As Integer)
Fader 0
End Sub
