Question

为动态控件添加事件 delphi

//该程序是在动态窗口中添加动态按钮，并指定按钮事件。完整测试代码如下：
program Project1;

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

var
MyButton1:TButton;
MyForm1:TForm;
{$R *.res}
Procedure MyButtonClick(Sender:TObject);
begin
ShowMessage('自定义事件');
end;

begin
MyForm1:=TForm.Create(Application);
MyForm1.Show;
MyButton1:=TButton.Create(Application);
MyButton1.Parent:=MyForm1;
MyButton1.OnClick:=MyButtonClick;//此处错误提示：
//Incompatible types:'method pointer and regular procedure'
end.

Answer 1

MyButtonClick过程需要属于某个对象，才可以；即MyButtonClick需要定义在某个对象内部，且要符合Procedure (Sender:TObject) 规范；然后再赋值给MyButton1.OnClick。
例如：
================================================================
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
procedure Button1Click2(Sender: TObject);
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}
procedure TForm1.Button1Click2(Sender: TObject);
begin
//
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
button1.on .OnClick:= Button1Click2;
end;

end.

追问

就我写的那个测试程序来看，应该怎样调整，因为窗体也是动态生成的。

追答

你可以继承TForm，创建个TForm子类，比如 TBaseForm，然后在TBaseForm中定义一个MyButtonClick,然后：
MyForm1:=TBaseForm.Create(Application);
...
MyButton1.OnClick:=TBaseForm(MyForm1).MyButtonClick;

应该就可以了。
...

Answer 2

 事件方法必须是类实例的方法.

type
   TEventHandlers = class { 建一个虚拟类}
       procedure MyButtonClick(Sender:TObject);
   end;
 
...
var 
  EvHandler:TEventHandlers;
 
implementation
 
{方法实现}
procedure TEventHandlers.MyButtonClick(Sender:TObject); 
begin 
      ShowMessage('自定义事件');
end;
 
 
 
{使用}
MyButton1.OnClick:=EvHandler.MyButtonClick;

Answer 3

简单测试通过，自己稍微改下

program Project1;

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls,

Unit1 in 'Unit1.pas' {Form1};
type lForm = class(TForm)
public
Procedure MyButtonClick(Sender:TObject);
end;
{$R *.res}
var
MyButton1:TButton;
mForm: lForm;

Procedure lForm.MyButtonClick(Sender:TObject);
begin
ShowMessage('自定义事件');
end;

begin
Application.Initialize;
Application.CreateForm(TForm1, Form1);
MyButton1:=TButton.Create(Application);
MyButton1.Parent:=Form1;
mForm:= lForm.CreateNew(nil);
MyButton1.OnClick:= mform.MyButtonClick;//
Application.Run;
end.