Re: Icon transparency after Serialization
- From: "Mike_IntermediateVB" <MikeIntermediateVB@xxxxxxxxxxxxxxxxxxxxxxxxx>
- Date: Mon, 17 Oct 2005 12:39:03 -0700
Thanks Michael, I'll do some more research (and a lot of Learning) and try
and follow your suggestions. Thanks again for your help.
"Michael Phillips, Jr." wrote:
> There are a few problems with your approach.
>
> > myIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon)
>
> The HICON returned from the SHGetFileInfo method
> should be disposed with DestroyIcon after you have
> finished with the handle.
>
> The System.Drawing.Icon class is a wrapper around the
> gdiplus API. Gdiplus does not have an encoder for the
> Icon format.
>
> I would not serialize a reference to a gdiplus icon. I would
> take the handle returned from SHGetFileInfo and use
> GetIconInfo to obtain the handles to the AND and XOR
> bitmap masks.
>
> From these handles you can use the Bitmap class to extract
> just the bits. You must use the Marshal class to read the bytes.
> From the bits you can construct a packed DIB which
> consists of a BITMAPINFOHEADER followed by the RGBQUAD
> color table followed by the XOR and AND bits.
>
> You can then use the MemoryStream class to serialize this chunk of
> memory.
>
> When you need to create the Icon (i.e., HICON) use the function
> CreateIconFromResourceEx function which requires a packed DIB
> to create the HICON.
>
>
> "Mike_IntermediateVB" <MikeIntermediateVB@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote
> in message news:04A97959-037C-423D-A443-AAD18BA0B876@xxxxxxxxxxxxxxxx
> > "Michael Phillips, Jr." wrote:
> >> How are you serializing the HICON that is returned?
> >
> > Thanks for reply I will spend a bit of time trying to understand the API,
> > below is a sample of the way I am capturing the Icons.
> > I create an Obj and add the ResourceIconCollection to it. Then add icons
> > by
> > Object.ResourceIconCollection.AddIcon(IconPath). Then serialise the whole
> > obj
> > using....
> >
> > Private Function SerilaiseObject() As Byte()
> > Dim serializer As New BinaryFormatter
> > Dim objData As New MemoryStream
> > serializer.Serialize(objData, obj)
> > objData.Seek(0, 0)
> > Return objData.ToArray()
> > End Function
> >
> > then I compress the byte array and save it to the database.
> >
> > Code..............
> >
> > '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > '--List of ICONs
> > '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > <Serializable()> Public Class ResourceIconCollection
> > Public IconList As New ArrayList
> > Public Function AddIcon(ByVal strPath)
> > If IconList.Count = 0 Then
> > Dim newIcon As New SingleIcon(strPath)
> > IconList.Add(newIcon)
> > Else
> > '--Check if Icon exsists
> > Dim Currenticon As SingleIcon
> > Dim FileExt As String =
> > LCase(System.IO.Path.GetExtension(strPath))
> > For Each Currenticon In IconList
> > If FileExt = Currenticon.Key Then
> > '--Icon extension has beem Found
> > Exit Function
> > End If
> > Next
> > '--No Exsisting Icons for this Extension found, so Add a new
> > one
> > Dim newIcon As New SingleIcon(strPath)
> > IconList.Add(newIcon)
> > End If
> >
> > End Function
> > End Class
> >
> > '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > '--Single ICON
> > '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >
> > <Serializable()> Public Class SingleIcon
> >
> > Public icon As System.Drawing.Icon
> > Public Key As String
> > Public Sub New()
> >
> > End Sub
> > Public Sub New(ByVal strPath As String)
> > icon = Icons.GetIcon(strPath)
> > Key = LCase(System.IO.Path.GetExtension(strPath))
> > End Sub
> >
> > End Class
> >
> >
> > '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > '--Get ICON
> > '++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > Imports System.Runtime.InteropServices
> > Public Class Icons
> > Private Structure SHFILEINFO
> > Public hIcon As IntPtr ' : icon
> > Public iIcon As Integer ' : icondex
> > Public dwAttributes As Integer ' : SFGAO_ flags
> > <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=260)> _
> > Public szDisplayName As String
> > <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=80)> _
> > Public szTypeName As String
> > End Structure
> >
> > Private Declare Auto Function SHGetFileInfo Lib "shell32.dll" _
> > (ByVal pszPath As String, _
> > ByVal dwFileAttributes As Integer, _
> > ByRef psfi As SHFILEINFO, _
> > ByVal cbFileInfo As Integer, _
> > ByVal uFlags As Integer) As IntPtr
> >
> > Private Const SHGFI_ICON = &H100
> > Private Const SHGFI_SMALLICON = &H1
> > Private Const SHGFI_LARGEICON = &H0 ' Large icon
> > Private nIndex = 0
> >
> > Public Shared Function GetIcon(ByVal strPathName As String) As
> > System.Drawing.Icon
> > '--Get Icon
> > Dim hImgSmall As IntPtr
> >
> > Dim shinfo As SHFILEINFO
> > shinfo = New SHFILEINFO
> >
> > shinfo.szDisplayName = New String(Chr(0), 260)
> > shinfo.szTypeName = New String(Chr(0), 80)
> >
> > 'Use this to get the small icon.
> > hImgSmall = SHGetFileInfo(strPathName, 0, shinfo, _
> > Marshal.SizeOf(shinfo), _
> > SHGFI_ICON Or SHGFI_SMALLICON)
> >
> > Dim myIcon As System.Drawing.Icon
> > myIcon = System.Drawing.Icon.FromHandle(shinfo.hIcon)
> >
> > Return myIcon
> > End Function
> >
> > End Class
>
>
>
.
- References:
- Re: Icon transparency after Serialization
- From: Michael Phillips, Jr.
- Re: Icon transparency after Serialization
- From: Mike_IntermediateVB
- Re: Icon transparency after Serialization
- From: Michael Phillips, Jr.
- Re: Icon transparency after Serialization
- From: Mike_IntermediateVB
- Re: Icon transparency after Serialization
- From: Michael Phillips, Jr.
- Re: Icon transparency after Serialization
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