Win32APIのCopyFileExのコールバックを受け入れる

CopyFileEx and callback

// Delphi 2007 and XE3
// Create form 'TForm1', place 2 Edit, 2 Button and 1 Label.
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    FAborted: Boolean;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{$WARN SYMBOL_PLATFORM OFF}

type
  TCopyProgressRoutine = function (TotalFileSize: Int64;
                                   TotalBytesTransferred: Int64;
                                   StreamSize: Int64;
                                   StreamBytesTransferred: Int64;
                                   dwStreamNumber: DWORD;
                                   dwCallbackReason: DWORD;
                                   hSourceFile: THandle;
                                   hDestinationFile: THandle;
                                   lpData: Pointer): DWORD; stdcall;

function CopyFileEx(lpExistingFileName: PChar;
                    lpNewFileName: PChar;
                    lpProgressRoutine: TCopyProgressRoutine;
                    lpData: Pointer;
                    pbCancel: PBool;
                    dwCopyFlags: DWORD): BOOL; stdcall; external kernel32
{$IFDEF UNICODE}
                    name 'CopyFileExW';
{$ELSE}
                    name 'CopyFileExA';
{$ENDIF}
{$EXTERNALSYM CopyFileEx}

const
  COPY_FILE_NO_BUFFERING = $00001000;

function CopyProgressFunc(TotalFileSize: Int64;
                          TotalBytesTransferred: Int64;
                          StreamSize: Int64;
                          StreamBytesTransferred: Int64;
                          dwStreamNumber: DWORD;
                          dwCallbackReason: DWORD;
                          hSourceFile: THandle;
                          hDestinationFile: THandle;
                          lpData: Pointer): DWORD; stdcall;
var
  TBT: Extended;
  TFS: Extended;
begin

  TFS := TotalFileSize;
  TBT := TotalBytesTransferred;

  with TObject(lpData) as TForm1 do
  begin
    if (TotalFileSize = 0) or (TotalBytesTransferred = 0) then
    begin
      Label1.Caption := '';
    end
    else
    begin
      Label1.Caption := Format('%.0n / %.0n bytes',[TBT,TFS]);
    end;

    Application.ProcessMessages;
    if FAborted = True then
    begin
      Result := PROGRESS_CANCEL;
    end
    else
    begin
      Result := PROGRESS_CONTINUE;
    end;
  end;

end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Canceled: BOOL;
  CopyFlags: DWORD;
begin

  FAborted := False;

  Button1.Enabled := False;
  try
    Canceled := False;
    CopyFlags := COPY_FILE_FAIL_IF_EXISTS;
    if CheckWin32Version(6,0) then
    begin
      CopyFlags := CopyFlags or COPY_FILE_NO_BUFFERING;
    end;
    Win32Check(CopyFileEx(PChar(Edit1.Text),PChar(Edit2.Text),
               CopyProgressFunc,Self,@Canceled,CopyFlags));

  finally
    Button1.Enabled := True;
  end;

end;

procedure TForm1.Button2Click(Sender: TObject);
begin

  FAborted := True;
  
end;

end.