unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button2: TButton;
    Button3: TButton;
    OpenDialog1: TOpenDialog;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses ShellAPI;

{ 从 EXE 或 DLL 中获取 ICO 图标的函数, 需要 uses ShellAPI }
function GetIco(const ExePath: string; SavePath: string): Integer; { 返回获取总数 }
var
  ico: TIcon;
  i, count: Integer;
  FileName: string;
begin
  Result := 0;
  count := ExtractIcon(HInstance, PChar(ExePath), $FFFFFFFF);
  if count = 0 then
    Exit;

  if not DirectoryExists(SavePath) then
    ForceDirectories(SavePath);
  FileName := ChangeFileExt(ExtractFileName(ExePath), '');
  SavePath := ExcludeTrailingPathDelimiter(SavePath)
    + '\' + FileName + '_%.3d.ico';

  ico := TIcon.Create;
  for i := 0 to count - 1 do
  begin
    ico.Handle := ExtractIcon(HInstance, PChar(ExePath), i);
    ico.SaveToFile(Format(SavePath, [i + 1]));
  end;
  ico.Free;
  Result := count;
end;

{ 测试: 获取当前程序图标 }
procedure TForm1.Button1Click(Sender: TObject);
begin
  GetIco(ParamStr(0), Application.ExeName + 'ICO');
end;

{ 测试: 获取记事本图标 }
procedure TForm1.Button2Click(Sender: TObject);
var
  buf: array [0 .. MAX_PATH] of Char;
begin
  // GetSystemDirectory(buf, Length(buf) * SizeOf(buf[0]));
  if OpenDialog1.Execute then
    GetIco(OpenDialog1.FileName, Application.ExeName + 'ICO');
  ShowMessage(Application.ExeName + 'ICO 中图片图片保存ok');
end;

{ 测试: 获取 Windows 的标准图标库 }
procedure TForm1.Button3Click(Sender: TObject);
var
  buf: array [0 .. MAX_PATH] of Char;
begin
  GetSystemDirectory(buf, Length(buf) * SizeOf(buf[0]));
  GetIco(buf + '\Shell32.dll', Application.ExeName + 'ICO 中图片图片保存ok');
end;

end.

窗体文件

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 194
  ClientWidth = 206
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Button2: TButton
    Left = 24
    Top = 32
    Width = 131
    Height = 25
    Caption = #33719#21462'dll,exe'#20013#30340'ICO'#22270#29255
    TabOrder = 0
    OnClick = Button2Click
  end
  object Button3: TButton
    Left = 24
    Top = 87
    Width = 161
    Height = 25
    Caption = #33719#21462#31995#32479'Shell32.dll'#20013'ico'#22270#29255
    TabOrder = 1
    OnClick = Button3Click
  end
  object OpenDialog1: TOpenDialog
    Left = 168
    Top = 24
  end
end