關於文件大小的問題?(10分)

amli · 2004-01-31

能夠用WriteFile把文件增大,能不能縮小呢. 例如ABC.DAT原大小為1024B,想把大小更為12B,但不能重新創建,是不是要改FAT,有哪位高手知道.

fei_l · 2004-01-31

可以的

fei_l · 2004-01-31

用流的方式来写，你要多少写都行

amli · 2004-01-31

怎麼搞,給你10分.

amli · 2004-01-31

不能重新創建文件.

fei_l · 2004-01-31

var   Stream1: TMemoryStream; begin   Stream1:=TMemoryStream.Create;   OpenDialog1.Execute;   Stream1.LoadFromFile(OpenDialog1.FileName);   stream1.Position:=0;   stream1.Size:=10;   // 只写10个字节   Stream1.SaveToFile('test.dat');   stream1.Free; end;

amli · 2004-01-31

你沒有明的我意思. Stream1.SaveToFile('abc.dat');//是不是要重創.

fei_l · 2004-01-31

Stream1.SaveToFile('abc.dat'); // 不保存能行吗？ 要不可以通过改变文件的大小的方法，但一样涉及到写的问题

amli · 2004-01-31

寫文件可以.

kaida · 2004-01-31

procedure TForm1.Button1Click(Sender: TObject); var   F: File;   Buf: array [0..0] of Char; begin   AssignFile(F, 'test.dat');   ReWrite(F, 1);   try     BlockWrite(F, Buf, 1);     Seek(F, 11); //改变文件大小为11+1=12字节。     BlockWrite(F, Buf, 1);   finally     CloseFile(F);   end; end;

amli · 2004-01-31

兩種方法都差不多,能不能在'test.dat'文件打開的情操作.

fei_l · 2004-01-31

// 从SaveToFile过程原型看 // 上例并不存在重创文件过程 procedure TCustomMemoryStream.SaveToFile(const FileName: string); var   Stream: TStream; begin   Stream := TFileStream.Create(FileName, fmCreate);   try     SaveToStream(Stream);   finally     Stream.Free;   end; end;

amli · 2004-01-31

//有呀: constructor TFileStream.Create(const FileName: string; Mode: Word; Rights: Cardinal); begin   if Mode = fmCreate then   begin     inherited Create(FileCreate(FileName, Rights));     if FHandle < 0 then       raise EFCreateError.CreateResFmt(@SFCreateError, [FileName]);   end   else   begin     inherited Create(FileOpen(FileName, Mode));     if FHandle < 0 then       raise EFOpenError.CreateResFmt(@SFOpenError, [FileName]);   end; end;

amli · 2004-01-31

接受答案了.

關於文件大小的問題?(10分)

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