Delphi中实现文件拷贝的三种方法 （收藏）

1.利用Windows API:

CopyFile(lpExistingFileName, lpNewFileName: PChar; bFailIfExists: BOOL): BOOL

 

procedure TFrmMain.Button1Click(Sender: TObject);
var
  sSo: string;
begin
  with TOpenDialog.Create(nil) do
  begin
    DefaultExt := 'xls';
    Filter := '*.xls';
    try
      if Execute then
        sSo := filename
      else
        exit;
    finally
      free;
    end;
  end;

  //就使用下面一句即可拷贝
  CopyFile(pchar(sSo), pchar('e:/x.xls'), false);

  //最后一参数True表示若存在相同目标文件则不拷贝，False表示无论目标文件是否存在都将覆盖
end;

 

 

2.文件流

function TFrmMain.CopyFile(sSour, sDest: string): Boolean;
var
  fSour, fDest: TFileStream;
begin
  Result := False;
  if not FileExists(sSour) then
    Exit;
  fSour := TFileStream.Create(sSour, fmOpenRead);
  fDest := TFileStream.Create(sDest, fmOpenWrite or fmCreate);
  try
    fDest.CopyFrom(fSour, fSour.Size);
    Result := FileExists(sDest);
  finally
    fDest.Free;
    fSour.Free;
  end;
end;

 

 

3．利用内存块读写buffer实现
procedure TFrmMain.FileCopy(const Fromfile,Tofile:string);
Var
  F1,F2:file;
  NumRead,Numwritten:Longint;
  Buf:array [1..2048] of char;
Begin
  AssignFile(F1,Fromfile);
  Reset(F1,1);
  AssignFile(F2,Tofile);
  Rewrite(F2,1);
  Repeat
    BlockRead(F1,buf,sizeof(buf),NumRead);
    BlockWrite(F2,buf,Numread,NumWritten);
  Until (NumRead=0) or (NumWritten<>NumRead);
  CloseFile(F1);
  CloseFile(F2);
End;