Fading An Icon Image

I'm using the SHGetFileInfo API get a handle to the 16 x 16 file icon, which all works fine.

How can I fade the icon image, like the Windows Explorer fades hidden files in Windows 2000.

I'm not using the ListView control so I can't use the Ghosted property, and I've already asked the API people and got no joy.

There must be a way of fading an icon image.


Help


Thanks in advance
:)

Well you could blend it 50/50 with a blank icon, or do a loop over the pixels of the icon to change the pixel colour to halfway between what it is and white...

Have you got any examples please?

This code doesnt work yet, but I'd do something long these lines :

VB Code:

Option Explicit
 
Private Declare Function GetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long) As Long
Private Declare Function SetPixel Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal crColor As Long) As Long
 
Private Sub Form_Load()
    Picture1.Picture = LoadPicture("c:\a.bmp")
    Me.Show
    HalfFadeToWhite Picture1
End Sub
 
Private Sub HalfFadeToWhite(destPic As PictureBox)
    Dim i As Long, j As Long, col As Long
    Dim colwhite As Long, colRed As Long, colGreen As Long, colBlue As Long
    colwhite = RGB(255, 255, 255)
    destPic.Visible = False
    For i = 0 To destPic.ScaleWidth
        For j = 0 To destPic.ScaleHeight
            col = GetPixel(destPic.hdc, i, j)
            colRed = ((col Mod 256) + 255) / 2
            colGreen = ((((col And &HFF00) / 256&) Mod 256&) + 255) / 2
            colBlue = (((col And &HFF0000) / 65536) + 255) / 2
            SetPixel destPic.hdc, i, j, RGB(colRed, colGreen, colBlue)
        Next
    Next
    destPic.Visible = True
    destPic.Refresh
End Sub

I like the idea.

I'm doing all this in a VB Active X DLL, and I don't want to add any forms to the project.

What is the easiest way to get a DC handle?

Create one using the CreateDC or CreateCompatibleDC API's, or use an existing one using the GetDC API.

If I was going to use an existing DC, which one would I use?
Can I use the Desktop DC?

Quote from MSDN :

<start quote>
CreateCompatibleDC
The CreateCompatibleDC function creates a memory device context (DC) compatible with the specified device.

HDC CreateCompatibleDC(
HDC hdc // handle to the device context
);

Parameters
hdc
Handle to an existing device context. If this handle is NULL, the function creates a memory device context compatible with the application's current screen.
<end quote>


So it would appear that if you pass a null as the parameter to the createcompatibledc function it'll create a new dc for you anyway.
So try that.

I've just tried:

lngDC = CreateCompatibleDC(0)

and it works . It returns the new compatible DC handle.


Nice one

:D