C＃将多个文件合并为一个

I'm working on a project whose concept is basically to act like a file container and gather files into one. So far, I created a "container" file, which has 2mb allocated at the beginning for indexing files. This part is a simple piece of XML where i store info such as filename, offset, filesize, etc. The rest is files added to the container forked after the 2mb allocated.I'm working on a project whose concept is basic