8

TTreeViewイベントを使用して最初からカスタム描画を行っていOnAdvancedCustomDrawItemますが、所有者描画アイテムの背景にこれらの選択範囲とホット長方形を正しくレンダリングする方法を知りたいですか？Vista / 7スタイルなので、背景を単色で塗りつぶすことはできません。

ここに画像の説明を入力してください

ステージでアイテムを描画しようとしましたが、ステージcdPostPaintを離れて選択範囲の背景を描画すると、アイテムのテキストを含む完全なデフォルトの描画が発生します。DefaultDraw := TruecdPrePaint

procedure TForm1.TreeView1AdvancedCustomDrawItem(Sender: TCustomTreeView;
  Node: TTreeNode; State: TCustomDrawState; Stage: TCustomDrawStage; var PaintImages,
  DefaultDraw: Boolean);
begin
  case Stage of
    cdPreErase:
    begin
      DefaultDraw := True;
    end;

    cdPostErase:
    begin
      DefaultDraw := True;
    end;

    cdPrePaint:
    begin
      // I thought this will paint only the selected/hot backgrounds, 
      // however this will paint whole item, including text.
      DefaultDraw := True;
    end;

    cdPostPaint:
    begin
      DefaultDraw := False;

      // painting my owner-draw text
      // .........
    end;
  end;

  PaintImages := False;
end;
4

1 に答える 1

14

これが私の解決策です（テスト済み）。

TreeViewはHotTrack := True通常、ホットアイテムを描画する必要があることに注意してください。

テーマが有効になっていない場合は、追加の描画も必要です。

uses
  UxTheme,
  Themes;

const
  TreeExpanderSpacing = 6;

procedure TForm1.DrawExpander(ACanvas: TCanvas; ATextRect: TRect; AExpanded: Boolean;
  AHot: Boolean);
var
  ExpanderRect: TRect;
  Graphics: IGPGraphics;
  Points: array of TGPPoint;
  Brush: IGPBrush;
  Pen: IGPPen;
  ThemeData: HTHEME;
  ElementPart: Integer;
  ElementState: Integer;
  ExpanderSize: TSize;
  UnthemedColor: TColor;
begin
  if ThemeServices.ThemesEnabled then
  begin
    if AHot then
      ElementPart := TVP_HOTGLYPH
    else
      ElementPart := TVP_GLYPH;

    if AExpanded then
      ElementState := GLPS_OPENED
    else
      ElementState := GLPS_CLOSED;

    ThemeData := OpenThemeData(TreeView1.Handle, VSCLASS_TREEVIEW);
    GetThemePartSize(ThemeData, ACanvas.Handle, ElementPart, ElementState, nil,
      TS_TRUE, ExpanderSize);
    ExpanderRect.Left := ATextRect.Left - TreeExpanderSpacing - ExpanderSize.cx;
    ExpanderRect.Right := ExpanderRect.Left + ExpanderSize.cx;
    ExpanderRect.Top := ATextRect.Top + (ATextRect.Bottom - ATextRect.Top - ExpanderSize.cy) div 2;
    ExpanderRect.Bottom := ExpanderRect.Top + ExpanderSize.cy;
    DrawThemeBackground(ThemeData, ACanvas.Handle, ElementPart, ElementState, ExpanderRect, nil);
    CloseThemeData(ThemeData);
  end
  else
  begin

    // Drawing expander without themes enabled

    Graphics := TGPGraphics.Create(ACanvas.Handle);
    Graphics.SmoothingMode := SmoothingModeHighQuality;

    ExpanderRect := ATextRect;
    ExpanderRect.Right := ATextRect.Left - TDPIAware.GetScaledSize(TreeExpanderSpacing96dpi);
    ExpanderRect.Left := ATextRect.Left - TDPIAware.GetScaledSize(TreeExpanderSpacing96dpi) -
      TDPIAware.GetScaledSize(Max(TreeExpanderCollapsedWidth96dpi, TreeExpanderExpandedWidth96dpi));

    if ASelected then
      UnthemedColor := ColorToRGB(clHighlightText)
    else
      if AExpanded then
        UnthemedColor := clBlack
      else
        UnthemedColor := clGray;

    SetLength(Points, 3);
    if AExpanded then
    begin
      Points[0] := TGPPoint.Create(ExpanderRect.Right, ExpanderRect.Top +
        (ExpanderRect.Bottom - ExpanderRect.Top - TreeExpanderExpandedHeight96dpi) div 2);
      Points[1] := TGPPoint.Create(ExpanderRect.Right, ExpanderRect.Top +
        (ExpanderRect.Bottom - ExpanderRect.Top + TreeExpanderExpandedHeight96dpi) div 2);
      Points[2] := TGPPoint.Create(ExpanderRect.Right - TreeExpanderExpandedWidth96dpi,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top +
        TreeExpanderExpandedHeight96dpi) div 2);
      Brush := TGPSolidBrush.Create(TGPColor.CreateFromColorRef(UnthemedColor));
      Graphics.FillPolygon(Brush, Points);
    end
    else
    begin
      Points[0] := TGPPoint.Create(ExpanderRect.Right - TreeExpanderCollapsedWidth96dpi,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top -
        TreeExpanderCollapsedHeight96dpi) div 2);
      Points[1] := TGPPoint.Create(ExpanderRect.Right,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top) div 2);
      Points[2] := TGPPoint.Create(ExpanderRect.Right - TreeExpanderCollapsedWidth96dpi,
        ExpanderRect.Top + (ExpanderRect.Bottom - ExpanderRect.Top +
        TreeExpanderCollapsedHeight96dpi) div 2);
      Pen := TGPPen.Create(TGPColor.CreateFromColorRef(UnthemedColor));
      Graphics.DrawPolygon(Pen, Points);
    end;
  end;
end;

procedure TForm1.TreeView1AdvancedCustomDrawItem(Sender: TCustomTreeView;
  Node: TTreeNode; State: TCustomDrawState; Stage: TCustomDrawStage; var PaintImages,
  DefaultDraw: Boolean);
var
  NodeRect: TRect;
  NodeTextRect: TRect;
  Text: string;
  ThemeData: HTHEME;
  TreeItemState: Integer;
begin
  if Stage = cdPrePaint then
  begin
    NodeRect := Node.DisplayRect(False);
    NodeTextRect := Node.DisplayRect(True);

    // Drawing background
    if (cdsSelected in State) and Sender.Focused then
      TreeItemState := TREIS_SELECTED
    else
      if (cdsSelected in State) and (cdsHot in State) then
        TreeItemState := TREIS_HOTSELECTED
      else
        if cdsSelected in State then
          TreeItemState := TREIS_SELECTEDNOTFOCUS
        else
          if cdsHot in State then
            TreeItemState := TREIS_HOT
          else
            TreeItemState := TREEITEMStateFiller0;

    if TreeItemState <> TREEITEMStateFiller0 then
    begin
      ThemeData := OpenThemeData(Sender.Handle, VSCLASS_TREEVIEW);
      DrawThemeBackground(ThemeData, Sender.Canvas.Handle, TVP_TREEITEM, TreeItemState,
        NodeRect, nil);
      CloseThemeData(ThemeData);
    end;

    // Drawing expander
    if Node.HasChildren then
      DrawExpander(Sender.Canvas, NodeTextRect, Node.Expanded, cdsHot in State);

    // Drawing main text
    SetBkMode(Sender.Canvas.Handle, TRANSPARENT);
    SetTextColor(Sender.Canvas.Handle, clBlue);

    Text := Node.Text;
    Sender.Canvas.TextRect(NodeTextRect, Text,
      [tfVerticalCenter, tfSingleLine, tfEndEllipsis, tfLeft]);

    // Some extended drawing...

  end;

  PaintImages := False;
  DefaultDraw := False;
end;
于 2012-06-07T16:39:51.350 に答える