Mega Code Archive
Working with TStream
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Title: Working with TStream
Question: How to get a lot of files in one stream
And get it back to :)
Answer:
Some times i want to Have multiple files in a stream couse then i dont have to send a lot of files but just one .
So heres a little code sniped to get it in and out again.
Procedure TForm1.ThisISHowIPutFilesIn ;
var
ABigFileStream, SomeSmallFiles : TMemoryStream ;
begin
ABigFileStream := TMemoryStream.Create ;
try
SomeSmallFiles := TMemoryStream.Create ;
try
SomeSmallFiles.LoadFromFile('C:\SomeSmalFile1.txt');
AddToStream(SomeSmallFiles,ABigFileStream);
SomeSmallFiles.LoadFromFile('C:\SomeSmalFile2.txt');
AddToStream(SomeSmallFiles,ABigFileStream);
// enz
finally
SomeSmallFiles.Free ;
end;
ABigFileStream.SaveToFile('C:\MrBig.DDD')
finally
ABigFileStream.free ;
end;
end;
Procedure TForm1.ThisISHowIGetStufOut ;
var
ABigFileStream, SomeSmallFiles : TMemoryStream ;
begin
ABigFileStream := TMemoryStream.Create ;
try
ABigFileStream.LoadFromFile('C:\MrBig.DDD');
SomeSmallFiles := TMemoryStream.Create ;
try
GetFromStream(ABigFileStream,SomeSmallFiles,0);
SomeSmallFiles.SaveToFile('C:\SomeSmalFile1.txt');
GetFromStream(ABigFileStream,SomeSmallFiles,1);
SomeSmallFiles.SaveToFile('C:\SomeSmalFile2.txt');
// enz
finally
SomeSmallFiles.Free ;
end;
finally
ABigFileStream.free ;
end;
end;
Procedure TForm1.AddToStream ( Source , Dest : TStream );
var
Size : Integer ;
begin
Source.position := 0 ;
// Keep the size by puting it in the first byte
Size := Source.Size ;
Dest.Write(Size,SizeOf(Integer));
Dest.CopyFrom(Source,Source.size);
end;
Procedure TForm1.GetFromStream ( Source , Dest : TStream ; Index : Integer );
Var
Size , I : Integer ;
begin
Source.Position := 0 ;
For i := 0 to index-1 do
begin
Source.Read(Size,SizeOf(Integer));
Source.Position := Source.Position + Size ;
end;
// if where all the way up the file pointer then someting went wrong :(
if Source.position = Source.Size then Raise EAccessViolation.Create('Index Out Of Bounds') ;
// Get the desired file size
Source.Read(Size,SizeOf(Integer));
// Clear Dest Buffer
Dest.Position := 0 ;
Dest.Size := 0 ;
Dest.CopyFrom(Source,Size);
end;
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