Custom MessageBox icon background white - delphi

Question

I'm using a class for custom messageboxes. But my problem is that, icon background is always white. Code below displays the icons. Can somebody tell me what is wrong in this code? I want icon background to be transparent.
try
if not custb then
case i of
MB_ICONINFORMATION:ico.Handle := LoadIcon( 0, IDI_INFORMATION);
MB_ICONEXCLAMATION:ico.Handle := LoadIcon( 0, IDI_EXCLAMATION);
MB_ICONQUESTION:ico.Handle := LoadIcon( 0, IDI_QUESTION);
MB_ICONERROR:ico.Handle := LoadIcon( 0, IDI_ERROR);
end;
with timage.Create( frm) do
begin
parent := frm;
transparent := True;
if custb then
begin
height := glyph.Height;
width := Glyph.Width;
end
else
begin
height := ico.Height;
width := ico.Width;
end;
ih := height;
top := Height div 2 + 2;
it := Top;
left := Width div 2 + 2;
il := Left + width + width div 2;
if width <= 16 then
begin
il := il + 16;
left := left + 8;
end;
if height <= 16 then
begin
it := it + 8;
top := top + 8;
end;
if custb then picture := Glyph else canvas.Draw( 0, 0, ico);
end;
finally
end;
if not custb then ico.Free;
end
Best wishes,
evilone

Answer 1

My code to do this very thing looks like this:
function StandardDialogIcon(DlgType: TMsgDlgType): PChar;
begin
case DlgType of
mtWarning:
Result := IDI_WARNING;
mtError:
Result := IDI_ERROR;
mtInformation:
Result := IDI_INFORMATION;
mtConfirmation:
Result := IDI_QUESTION;
else
Result := nil;
end;
end;
...
Image.Picture.Icon.Handle := LoadIcon(0, StandardDialogIcon(DlgType));
There's no need to set any properties on Image, you can simply ignore Transparent.

Answer 2

Extract from online help for TImage.Transparent:
Setting Transparent sets the
Transparent property of the Picture.
Note: Transparent has no effect
unless the Picture property specifies
a TBitmap object.
This means two things for you:
only set transparent property after the picture has been assigned
Use TBitmap for your image and assign thtat to the picture property.
Have a look at the following link, that describes a function that converts an icon to a bitmap: Delph-Library: Convert icon to bitmap.
Excerpt:
// Konvertiert Ico zu Bitmap
procedure IcoToBmpA(Ico: TIcon; Bmp: TBitmap; SmallIcon: Boolean);
var
WH: Byte; // Width and Height
begin
with Bmp do begin
Canvas.Brush.Color := clFuchsia;
TransparentColor := clFuchsia;
Width := 32; Height := 32;
Canvas.Draw(0, 0, Ico);
if SmallIcon then WH := 16 else WH := 32;
Canvas.StretchDraw(Rect(0, 0, WH, WH), Bmp);
Width := WH; Height := WH;
Transparent := True;
end;
end;