Delphi 两种获取文件大小的方法 (支持大文件)

方法1:
function GetFileSize(const strFileName: string): Int64;
var
  Handle: THandle;
  FindData: TWin32FindData;
  nFileSize: Int64;
begin
  Result := -1;
  Handle := FindFirstFile(PChar(strFileName), FindData);
  if Handle <> INVALID_HANDLE_VALUE then
  begin
    Windows.FindClose(Handle);
    if (FindData.dwFileAttributes and FILE_ATTRIBUTE_DIRECTORY) = 0 then
    begin
      Int64Rec(nFileSize).Lo := FindData.nFileSizeLow;
      Int64Rec(nFileSize).Hi := FindData.nFileSizeHigh;
      Result := nFileSize;
    end;
  end;
end;

方法2:
function GetFileSize(const strFileName: string): Int64;
var
  sr: TSearchRec;
begin
  if not FileExists(strFileName) then
  begin
    Result := -1;
    Exit;
  end;
  if FindFirst(strFileName, faAnyFile, sr) = 0 then
    Result := Int64(sr.FindData.nFileSizeHigh) shl 32 + Int64(sr.FindData.nFileSizeLow)
  else
    Result := -1;
  FindClose(sr);
end;