两个TRichEdit同时滚动

Question

怎么让两个TRichEdit同时滚动？

Answer 1

子类化RichEdit，截获WM_VSCROLL消息，并向另一个RichEdit发送WM_VSCROLL

Answer 2

继承RichEdit,截获WM_VSCROLL或WM_HSCROLL消息,加一个OnVScroll和OnHScroll事件,然后在这个控件的这两件事件中调整另一个RichEdit的滚动条
可以参考下面的代码,以下是我继承TScrollBox控件,是为了让这个ScrollBox滚动条动的时候另一个也动,下面的代码只是截获滚动消息定义了滚动事件
unit U_PicScrollBox;interfaceuses Classes, Forms, Controls, Messages,Windows, cxImage;type
  TPicScrollBox = class(TScrollBox)
  private
    FcxImage: TcxImage;
    FOnVScroll:TNotifyEvent;
    FOnHScroll:TNotifyEvent;
  protected
    procedure WMVScroll(var Message:TWMScroll);message WM_VSCROLL;
    procedure WMHScroll(var Message:TWMScroll);message WM_HSCROLL;
  published
    property cxImage:TcxImage read FcxImage write FcxImage;
    property OnVScroll:TNotifyEvent read FOnVScroll write FOnVScroll;
    property OnHScroll:TNotifyEvent read FOnHScroll write FOnHScroll;
  public
    constructor Create(AOwner: TComponent);override;
  end;implementation{ TPicScrollBox }constructor TPicScrollBox.Create(AOwner: TComponent);
begin
  inherited;
  cxImage:=TcxImage.Create(Self);
  cxImage.Parent:=Self;
  cxImage.AutoSize:=True;
  cxImage.Properties.PopupMenuLayout.MenuItems:=[];
  cxImage.Enabled:=False;
end;procedure TPicScrollBox.WMHScroll(var Message: TWMScroll);
begin
  inherited;
  if Assigned(FOnHScroll) then FOnHScroll(Self);
end;procedure TPicScrollBox.WMVScroll(var Message: TWMScroll);
begin
  inherited;
  if Assigned(FOnVScroll) then FOnVScroll(Self);
end;end.