開啟資料夾並搜尋檔案及得知其檔案大小

此可以做為新增MP3歌曲的功能，只要加入某個最上層目錄，就可以自動加入所有子目錄及其音樂。

新增2個TButton、1個TEdit、1個TMemo(ScrollBars屬性ssBoth)
兩個按鈕皆點兩下加入事件

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    procedure GetFileSize(sPath : string);
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1 : TForm1;
  Path : string;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  Dir: String;
begin
  Dir := '';
  if SelectDirectory('選擇文件夾', '', Dir) then
  begin
    if Copy(Dir,Length(Dir),1) <> '\' then
      Dir := Dir + '\';
    Edit1.text := Dir;  //Edit1顯示路徑
    Path := Dir;  //Path全域變數記錄Dir
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  GetFileSize(Edit1.text);
end;

procedure TForm1.GetFileSize(sPath : string);
var
  hFind     : THandle;
  filename, fPath  : string;
  nSize     : Int64;
  fd        : WIN32_FIND_DATA;
begin
  hFind:=Windows.FindFirstFile(PChar(sPath + '*.*'), fd); //所有檔案都找
  if(hFind <> INVALID_HANDLE_VALUE) then
  begin
    repeat
      filename:=fd.cFileName;
      fPath := sPath + filename;
      if((filename = '.') or (filename = '..')) then //不是上層 或 上上層
        Continue;
      if(fd.dwFileAttributes and FILE_ATTRIBUTE_DIRECTORY) > 0 then //是否為目錄
      begin
        GetFileSize(fPath + '\'); //遞迴呼叫 跑子目錄
      end else begin
        nSize:=fd.nFileSizeHigh;
        nSize:=nSize shl 32;
        nSize:=nSize or fd.nFileSizeLow;
        Memo1.lines.add(fPath+'       Size='+inttostr(nSize)=' bytes');
      end;
    until (not Windows.FindNextFile(hFind, fd));
    Windows.FindClose(hFind);
  end;
end;

end.