ImageList mit Alpha Channel

[HeinBlöd]

Da mir leider niemand geantwortet hat habe ich weiter nach einer Lösung gesucht.

This solution adds an icon with a predefined color count the the ImageList of Windows.

Maybe somebodyelse will implement a solution for TImageList too (since I don't need that I don't do it.)

Delphi-Quellcode:

function ImageList_LoadIcon(const ImageList: HIMAGELIST; const lpicon: LPWSTR; const uFlags: UINT): Integer;
type
  TIcoHeader = packed record
    Reserved: Word;
    FileType: Word;
    Count: Word;
  end;
  TIconHeader = packed record
    Width: Byte;
    Height: Byte;
    ColorCount: Byte;
    Reserved: Byte;
    Planes: Word;
    BitCount: Word;
    Size: DWord;
    FileOffset: DWord;
  end;
var
  IconSize: TPoint;
  FileStream: TFileStream;
  FileHeader: TIcoHeader;
  I: Integer;
  IconHeaderOffset: Int64;
  IconHeaderOffset8Bit: Int64;
  IconHeaderOffsetDefault: Int64;
  IconHeaderOffsetDefault8Bit: Int64;
  IconHeader: TIconHeader;
  IconStream: TMemoryStream;
  Icon: TIcon;
begin
  Result := -1;

  IconHeaderOffset := 0;
  IconHeaderOffset8Bit := 0;
  IconHeaderOffsetDefault := 0;
  IconHeaderOffsetDefault8Bit := 0;

  if (not ImageList_GetIconSize(ImageList, IconSize.X, IconSize.Y)) then
  begin
    IconSize.X := GetSystemMetrics(SM_CXICON);
    IconSize.Y := GetSystemMetrics(SM_CYICON);
  end;

  FileStream := TFileStream.Create(WideString(lpicon), fmShareDenyWrite);

  if (Assigned(FileStream)) then
  begin
    if (FileStream.Read(FileHeader, SizeOf(FileHeader)) = SizeOf(FileHeader)) then
      for I := 0 to FileHeader.Count - 1 do
        if (FileStream.Read(IconHeader, SizeOf(IconHeader)) = SizeOf(IconHeader)) then
        begin
          if ((IconHeader.Width = GetSystemMetrics(SM_CXICON)) and (IconHeader.Height = GetSystemMetrics(SM_CYICON))) then
          begin
            if (IconHeader.BitCount = 8) then
              IconHeaderOffsetDefault8Bit := FileStream.Position - SizeOf(IconHeader);

            if (((uFlags and ILC_COLOR4 = ILC_COLOR4) and (IconHeader.BitCount = 4))
              or ((uFlags and ILC_COLOR8 = ILC_COLOR8) and (IconHeader.BitCount = 8))
              or ((uFlags and ILC_COLOR16 = ILC_COLOR16) and (IconHeader.BitCount = 16))
              or ((uFlags and ILC_COLOR24 = ILC_COLOR24) and (IconHeader.BitCount = 24))
              or ((uFlags and ILC_COLOR32 = ILC_COLOR32) and (IconHeader.BitCount = 32))) then
              IconHeaderOffsetDefault := FileStream.Position - SizeOf(IconHeader);
          end;

          if ((IconHeader.Width = IconSize.X) and (IconHeader.Height = IconSize.Y)) then
          begin
            if (IconHeader.BitCount = 8) then
              IconHeaderOffset8Bit := FileStream.Position - SizeOf(IconHeader);

            if (((uFlags and ILC_COLOR4 = ILC_COLOR4) and (IconHeader.BitCount = 4))
              or ((uFlags and ILC_COLOR8 = ILC_COLOR8) and (IconHeader.BitCount = 8))
              or ((uFlags and ILC_COLOR16 = ILC_COLOR16) and (IconHeader.BitCount = 16))
              or ((uFlags and ILC_COLOR24 = ILC_COLOR24) and (IconHeader.BitCount = 24))
              or ((uFlags and ILC_COLOR32 = ILC_COLOR32) and (IconHeader.BitCount = 32))) then
              IconHeaderOffset := FileStream.Position - SizeOf(IconHeader);
          end;
        end;

    if (IconHeaderOffset = 0) then
      IconHeaderOffset := IconHeaderOffset8Bit;
    if (IconHeaderOffset = 0) then
      IconHeaderOffset := IconHeaderOffsetDefault;
    if (IconHeaderOffset = 0) then
      IconHeaderOffset := IconHeaderOffsetDefault8Bit;

    if (FileStream.Seek(IconHeaderOffset, soBeginning) = IconHeaderOffset) then
    begin
      FileStream.Read(IconHeader, SizeOf(IconHeader));
      FileStream.Seek(IconHeader.FileOffset, soBeginning);

      IconStream := TMemoryStream.Create();

      if (Assigned(IconStream)) then
      begin
        FileHeader.Count := 1;
        IconStream.Write(FileHeader, SizeOf(FileHeader));

        IconHeader.FileOffset := SizeOf(FileHeader) + SizeOf(IconHeader);
        IconStream.Write(IconHeader, SizeOf(IconHeader));

        IconStream.CopyFrom(FileStream, IconHeader.Size);

        Icon := TIcon.Create();
        if (Assigned(Icon)) then
        begin
          IconStream.Seek(0, soBeginning);
          Icon.LoadFromStream(IconStream);

          Result := ImageList_AddIcon(ImageList, Icon.Handle);

          Icon.Free();
        end;

        IconStream.Free();
      end;
    end;

    FileStream.Free();
  end;
end;