windows下文件复制和移动的原理是怎么样的呀

[aaronjin]

windows下文件复制和移动的原理是怎么样的呀
请专家们赐教

[huojiehai]

复制:拷贝原文件内容，再按原文件设置相应的文件信息（如：创建时间。。。）

移动：先是复制，再删除原文件

[aaronjin]

具体是怎么实现的

[huojiehai]

CopyFile

http://expert.csdn.net/Expert/topic/1656/1656068.xml?temp=6.054324E-02

中有很多

[xiangwangz]

{This way uses a File stream.}
Procedure FileCopy( Const sourcefilename, targetfilename: String );
Var
S, T: TFileStream;
Begin
S := TFileStream.Create( sourcefilename, fmOpenRead );

try
T := TFileStream.Create( targetfilename,
fmOpenWrite or fmCreate );
try
T.CopyFrom(S, S.Size ) ;
finally
T.Free;
end;
finally
S.Free;
end;
End;

{This way uses memory blocks for read/write.}
procedure FileCopy(const FromFile, ToFile: string);
var
FromF, ToF: file;
NumRead, NumWritten: Word;
Buf: array[1..2048] of Char;
begin
AssignFile(FromF, FromFile);
Reset(FromF, 1); { Record size = 1 }

AssignFile(ToF, ToFile); { Open output file }
Rewrite(ToF, 1); { Record size = 1 }
repeat
BlockRead(FromF, Buf, SizeOf(Buf), NumRead);
BlockWrite(ToF, Buf, NumRead, NumWritten);
until (NumRead = 0) or (NumWritten <> NumRead);
CloseFile(FromF);
CloseFile(ToF);
end;

{This one uses LZCopy, which USES LZExpand.}
procedure CopyFile(FromFileName, ToFileName: string);
var
FromFile, ToFile: File;
begin
AssignFile(FromFile, FromFileName); { Assign FromFile to FromFileName }

AssignFile(ToFile, ToFileName); { Assign ToFile to ToFileName }
Reset(FromFile); { Open file for input }
try
Rewrite(ToFile); { Create file for output }
try
{ copy the file an if a negative value is returned }
{ raise an exception }
if LZCopy(TFileRec(FromFile).Handle, TFileRec(ToFile).Handle) < 0
then
raise EInOutError.Create('Error using LZCopy')
finally
CloseFile(ToFile); { Close ToFile }

end;
finally
CloseFile(FromFile); { Close FromFile }
end;
end;