Reads bytes from the stream into Buffer.
procedure ReadBuffer(var Buffer; Count: Longint);
Use ReadBuffer to read Count bytes from the stream into a buffer in cases where the number of bytes is known and fixed, for example when reading in structures. ReadBuffer is used internally for loading from a stream and copying from a stream.
ReadBuffer calls Read to do the actual reading. If Count bytes cannot be read from the stream, an EReadError exception is raised.