Sort Arrow in Listview

[toms]

Hallo,

Ersetze HDI_IMAGE einfach durch HDF_BITMAP.
Ich habe den Code - vielleicht auch interessant für andere - noch etwas erweitert.
Die SortDirection habe ich jedoch nicht vollständig implementiert.
Auch sollte der Code in eine eigene Komponente gepackt werden.

Delphi-Quellcode:

  private
    { Private declarations }
    FSortUpGlyph: TBitmap;
    FSortDownGlyph: TBitmap;
    procedure SetColumnImage(List: TListView; Column, Image: Integer; ShowImage: Boolean);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses
  CommCtrl;

type
  TSortDirection = (sdAscending, sdDescending);

procedure TForm1.SetColumnImage(List: TListView; Column, Image: Integer;
                                 ShowImage: Boolean);
var
  Align,hHeader: integer;
  HD: HD_ITEM;
begin
  hHeader := SendMessage(List.Handle, LVM_GETHEADER, 0, 0); 
  with HD do
  begin
    FillChar(HD, SizeOf(HD), 0);

    Mask := (HDI_BITMAP) or (HDI_FORMAT);

    pszText := PChar(List.Columns[Column].Caption);

    case List.Columns[Column].Alignment of
      taLeftJustify:  Align := HDF_LEFT;
      taCenter:       Align := HDF_CENTER;
      taRightJustify: Align := HDF_RIGHT;
    else
      Align := HDF_LEFT;
    end;

    if SortDirection = sdAscending then
        Hbm := SortUpGlyph.Handle
      else
        Hbm := SortDownGlyph.Handle;

    if ShowImage then
      fmt := HDF_STRING or HDF_BITMAP or HDF_BITMAP_ON_RIGHT
    else
      fmt := HDF_STRING or Align;

    iImage := Image;
  end;
  SendMessage(hHeader, HDM_SETITEM, Column, Integer(@HD));
end;

function CustomSortProc(Item1, Item2: TListItem; ParamSort: integer): integer; stdcall;
begin
  Result := -lstrcmp(PChar(TListItem(Item1).Caption),
                     PChar(TListItem(Item2).Caption));
end;

procedure TForm1.ListView1ColumnClick(Sender: TObject;
  Column: TListColumn);
var
  i : integer;
begin
  ListView1.CustomSort( @CustomSortProc, Column.Index );
  // This loop displays the icon in the selected column.
  for i := 0 to ListView1.Columns.Count - 1 do
    SetColumnImage(ListView1, i, 0, i = Column.Index);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  FSortUpGlyph := TBitmap.Create;
  FSortDownGlyph := TBitmap.Create;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  FSortUpGlyph.Free;
  FSortDownGlyph.Free;
end;