I am downloading an EXE file from internet using Indy (idHTTP), and I can use memorystream or filestream to save it to disk, but I really do not know if there is any difference between them (maybe in the result structure of the file?). I could't find yet an answer for this.
Where, here are 2 simple functions to simulate what I am doing:
Function DownloadMS(FUrl, Dest: String): Boolean;
var
Http: TIdHTTP;
Strm: TMemoryStream;
Begin
Result := False;
Http := TIdHTTP.Create;
Strm := TMemoryStream.Create;
With Http, Strm Do
Try
Try
Get(FUrl, Strm);
If (Size > 0) Then
Begin
Position := 0;
SaveToFile(Dest);
Result := True;
end;
Except
end;
Finally
Strm.Free;
Http.Free;
end;
end;
Function DownloadFS(FUrl, Dest: String): Boolean;
var
Http: TIdHTTP;
Strm: TFileStream;
Begin
Result := False;
Http := TIdHTTP.Create;
Strm := TFileStream.Create(Dest, fmCreate);
With Http, Strm Do
Try
Try
Get(FUrl, Strm);
Result := (Size > 0);
Except
end;
Finally
Strm.Free;
Http.Free;
end;
end;
What you experts think about using one or other type (memorystream or filestream)? Is there any difference in the structure of the EXE file when using one or other type? What type is recommended?
Thank you! Have a nice weekend!
There is no difference between TMemoryStream
or TFileStream
from the stream point of view.
They are both streams and hold a stream of bytes and are both derived from TStream
.
You can implement your function generalized like this
function DownloadToStream( const AUrl : String; ADest : TStream ): Boolean;
var
LHttp: TIdHTTP;
begin
LHttp := TIdHTTP.Create;
try
LHttp.Get( AUrl, ADest );
Result := ADest.Size > 0;
finally
LHttp.Free;
end;
end;
and call it with a TFileStream
var
LStream : TStream;
begin
LStream := TFileStream.Create( 'MyFile.exe', fmCreate );
if DownloadToStream( '', LStream ) then
...
end;
or TMemoryStream
or whatever stream instance you like