unit Unit1;

interface

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

type
TForm1 = class(TForm)
Panel1: TPanel;
Panel2: TPanel;
Edit1: TEdit;
Edit2: TEdit;
Edit3: TEdit;
Edit4: TEdit;
Edit5: TEdit;
Button1: TButton;
procedure Button1Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

{这应该使用递归函数}
procedure GetChildWindows(h: HWND);
var
buf: array[0..255] of Char; {这个缓冲区是获取类名用的, 如果不需要可以删除}
begin
h := GetWindow(h, GW_CHILD); {第一个子窗口}
while h <> 0 do
begin
{下面两行是要执行的操作, 并假定只处理 TEdit}
GetClassName(h, buf, Length(buf));
if buf = 'TEdit' then ShowMessageFmt('%s:%d', [buf, h]);

h := GetWindow(h, GW_HWNDNEXT); {下一个子窗口}
GetChildWindows(h); {递归}
end;
end;

{测试}
procedure TForm1.Button1Click(Sender: TObject);
begin
GetChildWindows(Handle);
end;

end.