Programmatically embed resources in a .NET assembl

Question

I have a compiled .NET assembly with a specific resource file embedded (named 'Script.xml'). I need to programmatically change it out for another.

Is this possible to do without recompiling from source?

Currently, I do a search for text I know is in the file and it works well. But I need to do it for another project where I don't know any of the contents of the resource file and I need to find another method.

FileStream exe = new FileStream(currentexe, FileMode.Open);

//find xml part of exefile
string find = "<?xml version=\"1.0\"?>";
string lastchars = new string(' ', find.Length);
while (exe.CanRead) {
    lastchars = lastchars.Substring(1) + (char)exe.ReadByte();
    if (lastchars == find) {
        exe.Seek(-find.Length, SeekOrigin.Current);
        break;
    }
}

//output serialized script
int bytenum = 0;
foreach (byte c in xml) {
    if (c == 0) break;
    exe.WriteByte(c);
    bytenum++;
}

//clean out extra data
while (bytenum++ < ScriptFileSize) {
    exe.WriteByte(0x20);
}
exe.Close();

Answer 1

You're probably looking for System.Runtime.Emit to dynamically compile an assembly.

Answer 2

Your current mechanism is very fragile - it won't work for signed assemblies (as the hash will change) or if you need to replace one resource with a larger one (as all the other offsets may move). It also has issues in terms of character encodings and the general mechanism to find the right point in the file anyway, but those are relatively unimportant given that I don't think the approach is appropriate to start with.

If you need replaceable resources, I'd put them in a different file altogether, which doesn't have the relatively delicate format of an assembly.

Answer 3

You can dynamically build Assemblies using reflection, specifically the AssemblyBuilder class, and include resources in your dynamically built assembly. I'm not sure it's possible to disassemble an existing assembly using reflection (although now I'm interested).

I would bark up another tree if possible.

Answer 4

You could use Cecil to open the assembly and insert a resource (I do). YMMV