如何将DBGrid作为某个组件的一个Published属性？

Question

我做了一个下拉列表控件,里面有一个DBGrid,我想要把他放在Published区域,以便在对象浏览器中编辑它的Columns属性.可是我发现,如果不设置DBGrid.SetSubComponent(True),则Columns将无法保存在dfm文件中,设置DBGrid.SetSubComponent(True)后,又发现无法读取Columns属性.请问各位有什么好办法解决这个问题?

Answer 1

unit AnyNurbsActions;interface
            
uses
  Windows, SysUtils, Variants, Classes, Controls, AnyStdCtrlsTools, AnyNurbs,
  AnyGlobalConsts, AnyXYs, AnyMap;
  
type
  TCreateNurbsAction=class(TCreateShapeAction)
  private
    LineTracker:TAnyNurbs;
  public
    //------------------------------------------------------------------------//
    constructor Create(AView: TAnyMap);override;
    destructor Destroy; override;
    //------------------------------------------------------------------------//
    class function ToolId:Word;override;
    class function ToolType:TToolType;override;
    //------------------------------------------------------------------------//
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState;
      X, Y: Integer); override;
    procedure MouseMove(Shift: TShiftState; X, Y: Integer); override;
    //------------------------------------------------------------------------//
    procedure Paint; override;
    procedure MarkNoTrackFrame; override;
    //------------------------------------------------------------------------//
  end;implementation{ TCreateNurbsAction }constructor TCreateNurbsAction.Create(AView: TAnyMap);
begin
  inherited Create(AView);
  LineTracker:=TAnyNurbs.Create;
end;destructor TCreateNurbsAction.Destroy;
begin
  LineTracker.Free;
  inherited Destroy;
end;procedure TCreateNurbsAction.MarkNoTrackFrame;
begin
  LineTracker.MarkNoTrackFrame;
end;procedure TCreateNurbsAction.MouseDown(Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  APolyLine:TAnyNurbs;
  Pt:TAny2DPoint;
  PointIndex:Integer;
  LocalTrackData:TAnyNurbsFrameData;
begin
  inherited;
  case Button of
    mbLeft:begin
      if LineTracker.InTracking then
      begin
        with LineTracker do
        begin
          ClearTrackFrame;
          {增加顶点}
          LocalTrackData:=TAnyNurbsFrameData(TrackData);
          Pt:=Parent.CanvasToClient(X, Y);
          PointIndex:=LocalTrackData.Points.Count-1;
          LocalTrackData.Points.CUEditXY(PointIndex, Pt.X, Pt.Y);
          LocalTrackData.Points.CUAddXY(Pt.X, Pt.Y);
          DrawTrackFrame;
        end;
      end
      else
      begin
        View.Container.CheckActiveEditLayer;
        with LineTracker do
        begin
          {则重新初始化LineTracker}
          Parent:=View.SelectionManager.Root;
          MapCanvas:=View.MapCanvas;
          Points.CUClear;
          {增加第一个点}
          Pt:=Parent.CanvasToClient(X, Y);
          Points.CUAddXY(Pt.X, Pt.Y);
          Points.CUAddXY(Pt.X, Pt.Y);
          {开始跟踪}
          BeginTrack;
        end;
      end;
    end;
    mbRight:begin
      with LineTracker do
      begin
        {如果正在编辑，则结束编辑}
        if InTracking then
        begin
          {结束跟踪}
          EndTrack;
          {创建多边形，并应用当前的LineTracker设置}
          APolyLine:=TAnyNurbs(CreateShapeAt(TAnyNurbs, 0, 0));
          APolyLine.Assign(LineTracker);
          AddAndRefresh(APolyLine);
        end;
      end;
    end;
  end;   
end;
procedure TCreateNurbsAction.MouseMove(Shift: TShiftState; X, Y: Integer);
var
  Pt:TAny2DPoint;
  PointIndex:Integer;
  LocalTrackData:TAnyNurbsFrameData;
begin
  inherited;
  with LineTracker do
    if InTracking then
    begin
      ClearTrackFrame;
      LocalTrackData:=TAnyNurbsFrameData(TrackData);
      Pt:=Parent.CanvasToClient(X, Y);
      PointIndex:=LocalTrackData.Points.Count-1;
      LocalTrackData.Points.Items[PointIndex]^:=Geo2DPoint(Pt.X, Pt.Y);
      DrawTrackFrame;
    end;
end;procedure TCreateNurbsAction.Paint;
begin
  if LineTracker.InTracking then
    LineTracker.DrawTrackFrame;
end;class function TCreateNurbsAction.ToolId: Word;
begin
  Result:=ID_TOOL_CREATE_NURBS;
end;class function TCreateNurbsAction.ToolType: TToolType;
begin
  Result:=ttCreate;
end;end.