delphi 分割文件合并文件的函数

//分割文件的函数

{参数 1 是要分割的文件名; 参数 2 是要风格文件的大小, 单位是 KB}

{分割后的文件名扩展名用序号替换}

function SplitFile(const FileName: string; Size: Cardinal): Boolean;

var

fStream: TFileStream; {原始文件}

toStream: TMemoryStream; {分文件}

p,i: Integer; {p 记录当前指针位置; i 记录这是第几个分的文件}

begin

Result := False;

Size := Size * 1024; {把大小的单位转换为字节}

fStream := TFileStream.Create(FileName, fmOpenRead);

p := 0;

i := 0;

toStream := TMemoryStream.Create;

while p < fStream.Size do

begin

toStream.Clear; {清空上次数据}

fStream.Position := p; {放好指针位置}

if fStream.Size-p < Size then Size := fStream.Size-p; {最后一个时, 有多少算多少}

toStream.CopyFrom(fStream, Size); {复制}

toStream.SaveToFile(FileName + '.' + IntToStr(i)); {保存}

Inc(i);

p := p + Size;

end;

fStream.Free;

toStream.Free;

Result := True;

end;

//合并文件, 参数是其中一个分文件名

function MergeFile(const FileName: string): Boolean;

var

ms: TMemoryStream; {读取分文件}

fs: TFileStream; {合并后的文件}

path: string;

i: Integer;

begin

path := ChangeFileExt(FileName,''); {去掉序号扩展名}

ShowMessage(path);

i := 0;

ms := TMemoryStream.Create;

fs := TFileStream.Create(path, fmCreate);

while FileExists(path + '.' + IntToStr(i)) do

begin

ms.LoadFromFile(path + '.' + IntToStr(i));

fs.CopyFrom(ms, 0); {TFileStream 不需要 SetSize; 但如果用 TMemoryStream 就需要}

Inc(i);

end;

ms.Free;

fs.Free;

end;

//测试分割

procedure TForm1.Button1Click(Sender: TObject);

begin

SplitFile('c:\temp\test.txt', 10);

end;

//测试合并

procedure TForm1.Button2Click(Sender: TObject);

begin

MergeFile('c:\temp\test.txt.0');

end;

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