Mega Code Archive
Draw bitmaps in a TComboBox
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Title: draw Bitmaps in a TComboBox?
// This code works also with a TListBox
var
Bitmap1, Bitmap2, Bitmap3, Bitmap4: TBitmap;
procedure TForm1.FormCreate(Sender: TObject);
begin
ComboBox1.Style := csOwnerDrawVariable;
//Set height of one item
ComboBox1.ItemHeight := 20;
//load all bitmaps
Bitmap1 := TBitmap.Create;
Bitmap1.LoadFromFile('chem16.bmp');
Bitmap2 := TBitmap.Create;
Bitmap2.LoadFromFile('chip16.bmp');
Bitmap3 := TBitmap.Create;
Bitmap3.LoadFromFile('factry16.bmp');
Bitmap4 := TBitmap.Create;
Bitmap4.LoadFromFile('skylin16.bmp');
//assign bitmaps with item objects - caption of the items: Bitmap 1 - Bitmap 4
ComboBox1.Items.AddObject('Bitmap 1', Bitmap1);
ComboBox1.Items.AddObject('Bitmap 2', Bitmap2);
ComboBox1.Items.AddObject('Bitmap 3', Bitmap3);
ComboBox1.Items.AddObject('Bitmap 4', Bitmap4);
end;
procedure TForm1.ComboBox1DrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
var
Bitmap: TBitmap;
Offset: Integer;
begin
offset := 0;
with ComboBox1.Canvas do
begin
FillRect(Rect);
Bitmap := TBitmap(ComboBox1.Items.Objects[Index]);
if Bitmap nil then
begin
//copy bitmap to combobox coordinate
BrushCopy(Bounds(Rect.Left + 2, Rect.Top + 2, Bitmap.Width,
Bitmap.Height), Bitmap, Bounds(0, 0, Bitmap.Width,
Bitmap.Height), clred);
Offset := Bitmap.Width + 8;
end;
//Set a caption to each item
TextOut(Rect.Left + Offset, Rect.Top, Combobox1.Items[Index]);
end;
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
//free all bitmap objects
bitmap1.Free;
bitmap2.Free;
bitmap3.Free;
bitmap4.Free;
end;
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