Delphi/Lazarus: Write Stream to Stream

Assuming having two streams, StreamA and StreamB, you can copy the content from StreamB into StreamA using the following code:

StreamB.Position := 0;
StreamA.CopyFrom(StreamB, StreamB.Size);

It is important to set the position to 0 first. Otherwise (if the current stream position is not 0) it will not be copied from the beginning of the stream (except, of course, you only want to copy a part of the stream beginning somewhere in the middle).

The second parameter of CopyFrom is the length that should be copied. With passing "StreamB.Size", the full length of the stream is copied, with values smaller than the size of the stream, it is possible to copy only a part of the stream.
Last update on 2024-01-23 | Created on 2014-12-17