delphi - 如何设置 VirtualStringTree 标头的颜色？

Question

VirtualStringTree 标头具有“背景”属性，但将其设置为不同的颜色不会改变颜色。我怀疑树是使用 Windows 主题呈现的。

如何设置颜色？

Answer 1

您可以使用属性THeader.Background，但您必须toThemeAware从TreeOptions.PaintOptions. 正如 TLama 在上面的评论中所说的那样，这将关闭主题。

---

我建议您使用事件OnAdvancedHeaderDraw和OnHeaderDrawQueryElements. hoOwnerDraw必须包含在内Header.Options才能生效。

在OnHeaderDrawQueryElements您设置Elements为（至少）[hpeBackground]并在OnAdvancedHeaderDraw您进行自定义绘图时。

请参阅此示例（来源）：

procedure TfrmMain.MyVSTHeaderDrawQueryElements(Sender: TVTHeader;
  var PaintInfo: THeaderPaintInfo; var Elements: THeaderPaintElements);
begin
  Elements := [hpeBackground];
end;

procedure TfrmMain.MyVSTAdvancedHeaderDraw(Sender: TVTHeader;
  var PaintInfo: THeaderPaintInfo; const Elements: THeaderPaintElements);
begin
  if hpeBackground in Elements then
  begin
    PaintInfo.TargetCanvas.Brush.Color := clFuchsia; // <-- your color here
    if Assigned(PaintInfo.Column) then
      DrawFrameControl(PaintInfo.TargetCanvas.Handle, PaintInfo.PaintRectangle, DFC_BUTTON, DFCS_FLAT or DFCS_ADJUSTRECT); // <-- I think, that this keeps the style of the header background, but I'm not sure about that
    PaintInfo.TargetCanvas.FillRect(PaintInfo.PaintRectangle);
  end;
end;

Answer 2

procedure TfrmDepositDefrayalSingly.vstItemsManuallyHeaderDrawQueryElements(Sender: TVTHeader;
  var PaintInfo: THeaderPaintInfo; var Elements: THeaderPaintElements);
begin
  Elements := [hpeBackground];
end;


procedure TfrmDepositDefrayalSingly.vstItemsManuallyAdvancedHeaderDraw(Sender: TVTHeader;
  var PaintInfo: THeaderPaintInfo; const Elements: THeaderPaintElements);
begin
  if hpeBackground in Elements then
  begin
    PaintInfo.TargetCanvas.Brush.Color := cGlobalVar.BasicColor;
    PaintInfo.TargetCanvas.FillRect(PaintInfo.PaintRectangle);

    if Assigned(PaintInfo.Column) then
    begin
      PaintInfo.TargetCanvas.Brush.Color := clGray;
      PaintInfo.TargetCanvas.FrameRect(PaintInfo.PaintRectangle);
    end;
  end;
end;