using System;

using System.Reflection;

using System.Linq.Expressions;

​

public class Program

{

    public static void Main()

    {

        var user = new User();

​

        user.TrySetValue(c => c.UserName, "User name");

        user.TrySetValue(c => c.Password, "Password");

        Console.WriteLine(user);    

​

        user.MakeReadonly();

​

        user.TrySetValue(c => c.IsReadOnly, false);

        user.TrySetValue(c => c.UserName, "some other value");

        user.TrySetValue(c => c.Password, "some other password");

        Console.WriteLine(user);    

    }

}

​

​

​

public interface IReadOnlyAbility

{

    bool IsReadOnly {get;}

    void MakeReadonly();

}

​

public class User : IReadOnlyAbility {

    public bool IsReadOnly {get; private set;}

    public string UserName { get; private set; }

    public string Password { get; private set; }

    public void MakeReadonly() => IsReadOnly = true;

    public override string ToString()

        => $"UserName:{UserName}, Password: {Password}, IsReadonly: {IsReadOnly}";

}

​

​

public static class IReadOnlyAbilityExtensions

{

    public static bool TrySetValue<T, TValue>(this T target, Expression<Func<T, TValue>> memberLambda, TValue value)

        where T : IReadOnlyAbility

    {

        if(target.IsReadOnly) return false;

        if (memberLambda.Body is MemberExpression memberSelectorExpression 

            && memberSelectorExpression.Member is PropertyInfo property 

            && property.Name != nameof(target.IsReadOnly))

        {

            property.SetValue(target, value, null);

            return true;

        }

        return false;

    }

}