Mega Code Archive
The five methods to copy file
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Title: The five methods to copy file
Question: There have five methods to copy file,you can chose one to use.
Answer:
No 1:
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;
No 2:{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);
System.CloseFile(FromF);
System.CloseFile(ToF);
end;
No 3.
{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) raise Exception.Create('Error using LZCopy')
finally
CloseFile(ToFile); { Close ToFile }
end;
finally
CloseFile(FromFile); { Close FromFile }
end;
end;
No 4:
procedure CopyFile(FromFileName, ToFileName: string);
var
shellinfo: TSHFileOpStructA;
Files:String;
begin
Files:=FromFileName+#0+#0;
with shellinfo do
begin
Wnd:=Self.handle;
wFunc:=FO_COPY;
pFrom:=PChar(Files);
pTo:=PChar(ToFileName);
fFlags:=FOF_NOCONFIRMATION or FOF_SILENT;
end;
SHFileOperation(shellinfo);
end;
No 5:
copyfile(PChar(FromFileName),PChar(ToFileName),False);
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