In question Dynamically replace the contents of a C# method? I found a good response from @ Logman. I do not have standing to ask it in the comments.
using System;
using System.Reflection;
using System.Runtime.CompilerServices;
namespace ReplaceHandles
{
class Program
{
static void Main(string[] args)
{
Injection.replace();
Target target = new Target();
target.test();
Console.Read();
}
}
public class Injection
{
public static void replace()
{
MethodInfo methodToReplace = typeof(Target).GetMethod("test", BindingFlags.Instance | BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
MethodInfo methodToInject = typeof(Target2).GetMethod("test", BindingFlags.Instance | BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public);
RuntimeHelpers.PrepareMethod(methodToReplace.MethodHandle);
RuntimeHelpers.PrepareMethod(methodToInject.MethodHandle);
ReplaceInner(methodToReplace, methodToInject);
}
static void ReplaceInner(MethodInfo methodToReplace, MethodInfo methodToInject)
{
unsafe
{
if (IntPtr.Size == 4)
{
int* inj = (int*)methodToInject.MethodHandle.Value.ToPointer() + 2;
int* tar = (int*)methodToReplace.MethodHandle.Value.ToPointer() + 2;
*tar = *inj;
}
else
{
ulong* inj = (ulong*)methodToInject.MethodHandle.Value.ToPointer() + 1;
ulong* tar = (ulong*)methodToReplace.MethodHandle.Value.ToPointer() + 1;
*tar = *inj;
}
}
}
}
public class Base
{
public virtual void test()
{
}
}
public class Target : Base
{
public override void test()
{
Console.WriteLine("Target.test()");
}
public void test3()
{
Console.WriteLine("Target.test3()");
}
}
public class Target2
{
public void test()
{
Console.WriteLine("Target.test2()");
}
}
}
Everything works, but does not work the replacement of overridden methods.
