using System;

using System.Collections.Generic;

using System.Linq.Expressions;

​

public class Program

{

​

    public static void Main()

    {

        var user = new User();

        user.Department = new Department();

        user.Department.Name = "hello";

        Console.WriteLine("Before: " + user.Department.Name);

        ParameterExpression paramExpr = Expression.Parameter(typeof(User), "user");

        MemberExpression depPropExpr = MemberExpression.Property(paramExpr, "Department");

        MemberExpression depNamePropExpr = MemberExpression.Property(depPropExpr, "Name");

        ConstantExpression constantExpression = Expression.Constant("SBCA");

​

        var expression = Expression.Assign(depNamePropExpr, constantExpression);

        var compiledExpression = Expression.Lambda<Action<User>>(expression, new[] { paramExpr }).Compile();

        compiledExpression(user);

        Console.WriteLine("After: " + user.Department.Name);

    }

}

​

public class User

{

    public Department Department { get; set; }

}

​

public class Department

{

    public string Name { get; set; }    

}