DirextX编程

开发平台：
Delphi

DrawPanel.pas：源码内容
							unit DrawPanel;
interface
uses
  Windows, SysUtils, Messages, Classes, Controls, ExtCtrls;
type
  TMsgProc=procedure (var Msg:TMessage; DefaultProcess:Boolean) of Object;
  TDrawPanel = class(TCustomPanel)
  private
    FOnPaint: TNotifyEvent;
    FEraseBackground: Boolean;
    FOnBeforeMsg: TMsgProc;
    FOnAfterMsg: TMsgProc;
    procedure SetOnPaint(const Value: TNotifyEvent);
    procedure WMERASEBKGND(var Msg:TWMERASEBKGND); Message WM_ERASEBKGND;
    procedure SetEraseBackground(const Value: Boolean);
    procedure SetOnAfterMsg(const Value: TMsgProc);
    procedure SetOnBeforeMsg(const Value: TMsgProc);
    { Private declarations }
  protected
    procedure Paint;override;
    procedure WndProc(var Msg:TMessage); override;
    { Protected declarations }
  public
    Constructor Create(Owner:TComponent);override;
    property DockManager;
    property Canvas;
  published
    property EraseBackground:Boolean read FEraseBackground write SetEraseBackground;
    property OnPaint:TNotifyEvent read FOnPaint write SetOnPaint;
    property Align;
    property Alignment;
    property Anchors;
    property AutoSize;
    property BevelInner;
    property BevelOuter;
    property BevelWidth;
    property BiDiMode;
    property BorderWidth;
    property BorderStyle;
    property Caption;
    property Color;
    property Constraints;
    property Ctl3D;
    property UseDockManager default True;
    property DockSite;
    property DragCursor;
    property DragKind;
    property DragMode;
    property Enabled;
    property FullRepaint;
    property Font;
    property Locked;
    property ParentBiDiMode;
    property ParentBackground;
    property ParentColor;
    property ParentCtl3D;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
    property ShowHint;
    property TabOrder;
    property TabStop;
    property Visible;
    property OnCanResize;
    property OnClick;
    property OnConstrainedResize;
    property OnContextPopup;
    property OnDockDrop;
    property OnDockOver;
    property OnDblClick;
    property OnDragDrop;
    property OnDragOver;
    property OnEndDock;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnGetSiteInfo;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
    property OnResize;
    property OnStartDock;
    property OnStartDrag;
    property OnUnDock;
    property OnBeforeMsg:TMsgProc read FOnBeforeMsg write SetOnBeforeMsg;
    property OnAfterMsg:TMsgProc read FOnAfterMsg write SetOnAfterMsg;
  end;
procedure Register;
implementation
procedure Register;
begin
  RegisterComponents('WH', [TDrawPanel]);
end;
{ TDrawPanel }
constructor TDrawPanel.Create(Owner: TComponent);
begin
    inherited;
    FEraseBackground:=true;
end;
procedure TDrawPanel.Paint;
begin
    inherited;
    
    if Assigned(FOnPaint) then
        FOnPaint(Self);
end;
procedure TDrawPanel.SetEraseBackground(const Value: Boolean);
begin
    FEraseBackground := Value;
end;
procedure TDrawPanel.SetOnAfterMsg(const Value: TMsgProc);
begin
    FOnAfterMsg := Value;
end;
procedure TDrawPanel.SetOnBeforeMsg(const Value: TMsgProc);
begin
    FOnBeforeMsg := Value;
end;
procedure TDrawPanel.SetOnPaint(const Value: TNotifyEvent);
begin
    FOnPaint := Value;
end;
procedure TDrawPanel.WMERASEBKGND(var Msg: TWMERASEBKGND);
Var
    Rec:TRect;
begin
    if FEraseBackground then
    begin
        Inherited;
    end
    else
    begin
        Rec:=Self.GetClientRect();
        ValidateRect(Handle,@Rec);
    end;
end;
procedure TDrawPanel.WndProc(var Msg: TMessage);
Var
    b:Boolean;
begin
    b:=true;
    if Assigned(FOnBeforeMsg) then
    begin
        FOnBeforeMsg(Msg,b);
        if Not b then
            Exit;
    end;
    inherited;
    b:=true;
    if Assigned(FOnAfterMsg) then
    begin
        FOnAfterMsg(Msg,b);
    end;
end;
end.

						