Is it possible to merge two streams using CopyTo method? - merge

Question

Is it possible to merge two (or more) Streams (or MemoryStreams) using CopyTo method?
For instance, I have two source streams s1 and s2. I'm creating the destination MemoryStream:
MemoryStream omDest = new MemoryStream();
If I copy one Stream everything is fine:
s1.CopyTo(omDest);
But if I copy both, the second one overwrites the first one.
I'd appreciate your help.
Thank you.

Answer 1

You can set the position of the target stream to the length of the first stream after CopyTo like this:
memoryStream1.CopyTo(target);
target.Position = memoryStream1.Length;
memoryStream2.CopyTo(target);
So the copying for the second stream starts at the specified position
Full Code:
using (MemoryStream target = new MemoryStream(30))
{
using(MemoryStream mem1 = new MemoryStream(new byte[] { 1, 2, 3, 4, 5 }))
{
mem1.CopyTo(target);
target.Position = mem1.Length;
}
using (MemoryStream mem2 = new MemoryStream(new byte[] { 6, 7, 8, 9, 10 }))
{
mem2.CopyTo(target);
}
foreach(byte b in target.ToArray())
{
Console.Write(b+",");
}
}
Best Regards
Flo
EDIT:
To make it simpler you could also use the WriteTo-Method, so you wouldn't need the resetting of the position.