Dynamically replace the contents of a C# method?

Question

What I want to do is change how a C# method executes when it is called, so that I can write something like this:

[Distributed]
public DTask Solve         


        

Answer 1

have a look into Mono.Cecil:

using Mono.Cecil;
using Mono.Cecil.Inject;

public class Patcher
{    
   public void Patch()
   {
    // Load the assembly that contains the hook method
    AssemblyDefinition hookAssembly = AssemblyLoader.LoadAssembly("MyHookAssembly.dll");
    // Load the assembly
    AssemblyDefinition targetAssembly = AssemblyLoader.LoadAssembly("TargetAssembly.dll");

    // Get the method definition for the injection definition
    MethodDefinition myHook = hookAssembly.MainModule.GetType("HookNamespace.MyHookClass").GetMethod("MyHook");
    // Get the method definition for the injection target. 
    // Note that in this example class Bar is in the global namespace (no namespace), which is why we don't specify the namespace.
    MethodDefinition foo = targetAssembly.MainModule.GetType("Bar").GetMethod("Foo");

    // Create the injector
    InjectionDefinition injector = new InjectionDefinition(foo, myHook, InjectFlags.PassInvokingInstance | InjectFlags.passParametersVal);

    // Perform the injection with default settings (inject into the beginning before the first instruction)
    injector.Inject();

    // More injections or saving the target assembly...
   }
}