Can you extend a non partial method in a partial class?

Question

I have a generated partial class

public partial interface IPartialInterface
{
   Task<object> Method(string param)
}
public partial class PartialClass : IPartialInterface
{
    public Task<object> Method(string param)
    {
        // does stuff
    }
}

I want to extend the Method so I can plug some logic and then depending on my logic let the PartialClass.Method logic take over or stop it.

Answer 1

For people with the same problem, this worked for me:

    public partial interface IGeneratedPartialInterface
    {
        Task<object> Method(string param)
    }
    public partial class GeneratedPartialClass : IGeneratedPartialInterface
    {
        public Task<object> Method(string param)
        {
             // does stuff
        }
    }
        
    public interface MyInterface
    {
        Task<object> MethodExtended(string param)
    }
        
    // added by me, but must be named as the generated partial class
    public partial class GeneratedPartialClass : MyInterface
    {        
        public Task<object> MethodExtended(string param)
        {
            // my logic here example
            if (isInCache(param))
            {
                // do stuff
            }
            else 
            {
                return this.Method(param)
            }
        }
    }