如何创建继承自少数其他组件的Delphi组件

Question

我发现的关于如何创建delphi组件的教程很好，但它们只使用一个现有组件作为对象来继承操作。像这样的

unit CountBtn;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ExtCtrls;
type
TCountBtn = class(TButton)
private
FCount: integer;
protected
procedure Click;override;
public
procedure ShowCount;
published
property Count:integer read FCount write FCount;
constructor Create(aowner:Tcomponent); override;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Mihan Components', [TCountBtn]);
end;
constructor TCountBtn.Create(aowner:Tcomponent);
begin
inherited create(Aowner);
end;
procedure Tcountbtn.Click;
begin
inherited click;
FCount:=FCount+1;
end;
procedure TCountBtn.ShowCount;
begin
Showmessage('On button '+ caption+' you clicked: '+inttostr(FCount)+' times');
end;
end.

但是，如果我需要使用很少元素的组件，该怎么办？比方说，我得到了Button和Edit字段。点击编辑栏中的按钮，应该显示与点击按钮相同的文本。我开始这样做，但似乎不会像我想要的那样工作：

unit TestComp;
interface
uses
System.SysUtils, System.Classes, Vcl.Controls, Vcl.StdCtrls, Vcl.ExtCtrls;
type
TUiCompU = class(TCustomControl)
private
{ Private declarations }
FButton: TButton;
FEdit: TEdit;
protected
{ Protected declarations }
procedure Paint; override;
//wrong!
procedure FButton.Click;override
public
{ Public declarations }
constructor Create(AOwner: TComponent); override;
published
{ Published declarations }
//wrong!
property ButtonText: String read FButton.Caption write FButton.Caption;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Ui', [TUiCompU]);
end;
{ TUiCompU }
constructor TUiCompU.Create(AOwner: TComponent);
begin
inherited;
Width := 200;
Height := 50;
FButton := TButton.Create(Self);
FButton.SetSubComponent(True);
FButton.Parent := Self;
FButton.Top := 8;
FButton.Left := 50;
FButton.Width := 35;
FButton.Name := 'Button';
FEdit := TEdit.Create(Self);
FEdit.SetSubComponent(True);
FEdit.Parent := Self;
FEdit.Top := 8;
FEdit.Left := 84;
FEdit.Width := 121;
FEdit.Name := 'Edit';
end;
procedure TUiCompU.Paint;
begin
Canvas.Rectangle(ClientRect);
end;
end.

我应该如何在这里添加Click过程，这是真正的点击按钮？有没有关于如何使用其他组件制作好组件的好教程？(我需要创建一些类似幻灯片组件btw的东西)。谢谢你，对不起我的英语。

Answer 1

您可以为子组件事件编写方法，但它有一个很大的弱点；如果你发布这些子组件，就有可能有人通过编写自己的方法来窃取你的绑定：

type
TUiCompU = class(TCustomControl)
private
FEdit: TEdit;
FButton: TButton;
procedure ButtonClick(Sender: TObject);
procedure EditKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
public
constructor Create(AOwner: TComponent); override;
end;
implementation
constructor TUiCompU.Create(AOwner: TComponent);
begin
inherited;
FButton := TButton.Create(Self);
...
FButton.OnClick := ButtonClick;
FEdit := TEdit.Create(Self);
...
FEdit.OnKeyDown := EditKeyDown;
end;
procedure TUiCompU.ButtonClick(Sender: TObject);
begin
// do whatever you want here
end;
procedure TUiCompU.EditKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
begin
// do whatever you want here
end;