파일복사 진행상황 보여주기

TCopyInfo = packed record
  Source: String[255];
  Dest: String[255];
  Handle: THandle;
end;
PCopyInfo = ^TCopyInfo;

const
  //사용자정의 메시지
  COPY_CANCEL = WM_USER + 1;
  COPY_CONTINUE = WM_USER + 2;
  COPY_MAXBYTES = WM_USER + 3;
  COPY_FAIL = WM_USER + 4;

var
  bCancel : Boolean = False;

function CopyFileProgress(TotalFileSize, TotalBytesTransferred, StreamSize,
  StreamBytesTransferred: LARGE_INTEGER; dwStreamNumber, dwCallbackReason,
  hSourceFile, hDestinationFile: DWORD; lpData: Pointer): DWORD; stdcall;
begin
  if bCancel then //Cancel Message
  begin
    SendMessage(THandle(lpData), COPY_CANCEL, 0, 0);
    Result := PROGRESS_CANCEL;
    Exit;
  end;

  case dwCallbackReason of
    CALLBACK_CHUNK_FINISHED: //Continue Message
      begin
        SendMessage(THandle(lpData), COPY_CONTINUE, TotalBytesTransferred.LowPart, TotalBytesTransferred.HighPart);
        Result := PROGRESS_CONTINUE;
      end;
    CALLBACK_STREAM_SWITCH: //Max Message
      begin
        SendMessage(THandle(lpData), COPY_MAXBYTES, TotalFileSize.LowPart, TotalFileSize.HighPart);
        Result := PROGRESS_CONTINUE;
      end;
  else
    Result := PROGRESS_CONTINUE; //Continue Message
  end;
end;

function CopyExThread(p: PCopyInfo): Integer;
var
  Source: String;
  Dest: String;
  Handle: THandle;
  Cancel : PBool;
begin
  Source := p.Source;
  Dest := p.Dest;
  Handle := p.Handle;
  Cancel := PBOOL(False);

  if not CopyFileEx(PChar(Source), PChar(Dest), @CopyFileProgress, Pointer(Handle), Cancel, COPY_FILE_FAIL_IF_EXISTS) then
  begin
    PostMessage(Handle, CEXM_FAIL, 0 , 0);
    ShowMessage('중복된 파일이 존재합니다.');
  end;

  Dispose(p);
  Result := 0;
end;

function FormatFileSize(Size: extended): string;
begin
  //파일사이즈 변환해서 보여주기
  if Size = 0 then
    Result := '0 B'
  else if Size < 1000 then
    Result := FormatFloat('0', Size) + ' B'
  else
  begin
    Size := Size / 1024;

    if (Size < 1000) then
      Result := FormatFloat('0.0', Size) + ' KB'
    else
    begin
      Size := Size / 1024;

      if (Size < 1000) then
        Result := FormatFloat('0.00', Size) + ' MB'
      else
      begin
        Size := Size / 1024;

        if (Size < 1000) then
          Result := FormatFloat('0.00', Size) + ' GB'
        else
        begin
          Size := Size / 1024;

          if (Size < 1024) then
            Result := FormatFloat('0.00', Size) + ' TB';
        end;
      end;
    end;
  end;
end;

사용방법

type
  TForm1 = class(TForm)
    ..
    Label1 : TLabel;
    ProgressBar : TProgressBar;
    procedure btnDownLoadClick(Sender: TObject);
  private
  public
    procedure WndProc(var Msg: TMessage); override;
  end;

procedure TForm1.WndProc(var Msg: TMessage);
begin
  inherited;

  case Msg.Msg of
    COPY_MAXBYTES:
      begin
        ProgressBar.Max := (Int64(Msg.LParam) shl 32) + Msg.WParam;
        ProgressBar.Visible := True;
      end;
    COPY_CONTINUE:
      begin
        Progressbar.Position := (Int64(Msg.LParam) shl 32) + Msg.WParam;
        Label1.Caption := '복사 중 : ' + FormatFileSize(Msg.WParam + Msg.LParam);
        
        if ProgressBar.Max <= ProgressBar.Position then
        begin
          ShowMessage('복사 완료!');
          ProgressBar.Visible := False;
        end;
      end;
    COPY_CANCEL:
    begin
      ShowMessage('복사 취소!');
      ProgressBar.Visible := False;
    end;
    COPY_FAIL:
      begin
        ShowMessage('복사 실패!');
        ProgressBar.Visible := False;
      end;
  end;
end;

procedure TForm1.btnDownLoadClick(Sender: TObject);
var
  CopyInfo : PCopyInfo;
  ThreadID : Cardinal;
begin
  bCancel := False;

  New(CopyInfo);
  CopyInfo.Source := '원본파일 경로';
  CopyInfo.Dest   := '저장파일 경로';
  CopyInfo.Handle := Handle;

  CloseHandle(BeginThread(nil, 0, @CopyExThread, CopyInfo, 0, ThreadID));
end;