Scrollbox的滚动条事件scrollbar事件的处理（Lazarus）

没办法，改源代码：

找到：Forms单元中scrollbox的父类：

TScrollingWinControl = class(TCustomControl) 

 

改：

{ TScrollingWinControl }

  //

  //begin

  TOnAfterScroll=procedure(ScrollKind: TScrollBarKind; OldPosition: Integer) of object;

  //end

  //  

 

 

TScrollingWinControl = class(TCustomControl)

  private

    FHorzScrollBar: TControlScrollBar;

    FVertScrollBar: TControlScrollBar;

    FAutoScroll: Boolean;

    FIsUpdating: Boolean;

    FonAfterScroll:TOnAfterScroll;//*********add by aliyagoo.com

    procedure SetHorzScrollBar(Value: TControlScrollBar);

    procedure SetVertScrollBar(Value: TControlScrollBar);

    function StoreScrollBars: Boolean;

  protected

    class procedure WSRegisterClass; override;

    procedure AlignControls(AControl: TControl; var ARect: TRect); override;

    procedure CreateWnd; override;

    function GetClientScrollOffset: TPoint; override;

    function GetLogicalClientRect: TRect; override;// logical size of client area

    procedure DoOnResize; override;

    procedure WMHScroll(var Message : TLMHScroll); message LM_HScroll;

    procedure WMVScroll(var Message : TLMVScroll); message LM_VScroll;

    function ComputeScrollbars: Boolean; virtual;

    procedure ScrollbarHandler(ScrollKind: TScrollBarKind;

                               OldPosition: Integer); virtual;

    procedure SetAutoScroll(Value: Boolean); virtual;

    procedure Loaded; override;

    property AutoScroll: Boolean read FAutoScroll write SetAutoScroll default False;

  public

    constructor Create(TheOwner : TComponent); override;

    destructor Destroy; override;

    procedure UpdateScrollbars;

    function HasVisibleScrollbars: boolean; virtual;

    class function GetControlClassDefaultSize: TPoint; override;

    procedure ScrollBy(DeltaX, DeltaY: Integer);

    property OnAfterScroll:TOnAfterScroll read FonAfterScroll write FonAfterScroll;//***********add by aliyagoo.com

  published

    property HorzScrollBar: TControlScrollBar

              read FHorzScrollBar write SetHorzScrollBar stored StoreScrollBars;

    property VertScrollBar: TControlScrollBar

              read FVertScrollBar write SetVertScrollBar stored StoreScrollBars;

  end;               

然后在Scrollbox里公开属性【公开，不是发布】。

 

插入事件：ScrollingWinControl.inc 文件

 

procedure TScrollingWinControl.ScrollbarHandler(ScrollKind: TScrollBarKind;

  OldPosition: Integer);

begin

  if ScrollKind = sbVertical then

    ScrollBy(0, FVertScrollBar.Position - OldPosition)

  else

    ScrollBy(FHorzScrollBar.Position - OldPosition, 0);

 

    //***********add by aliyagoo

    if Assigned(OnAfterScroll) then FOnAfterScroll(ScrollKind,OldPosition);

    //***********end add

end;                      

 

http://blog.sina.com.cn/s/blog_56294d0a0100w4lx.html