using System;

using System.Linq;

using System.Linq.Expressions;

public class Program

{

    public static void Main()

    {

        var inst = new MyType { MyInt1 = 1 };

        try

        {

            inst.NoValueTypedPropertyHasDefaultValue(x => x.MyInt2);

        }

        catch(Exception ex)

        {

            Console.WriteLine(ex);

        }

    }   

}

​

public class MyType

{

    public int MyInt1 { get; set; }

    public int MyInt2 { get; set; }

    public int MyInt3 { get; set; }

}

​

public static class Extensions

{

    public static void NoValueTypedPropertyHasDefaultValue<T>(this T t, params Expression<Func<T,object>>[] propertiesToIgnore)

        where T : class

    {

        var propertyNamesToIgnore = propertiesToIgnore.Select(x => GetMemberInfo(x).Member.Name).ToArray();

        foreach (var property in typeof(T).GetProperties())

        {

            var propertyType = property.PropertyType;

            if (propertyType.IsValueType && !propertyNamesToIgnore.Contains(property.Name))

            {

                var defaultValue = Activator.CreateInstance(propertyType);

                object actualValue = property.GetValue(t);

                //Assert.NotEqual(defaultValue, actualValue);

                if (defaultValue.Equals(actualValue)) throw new Exception($"Assert fail: {property.Name}");

            }

        }

    }

​

    private static MemberExpression GetMemberInfo(Expression method)

    {

        LambdaExpression lambda = method as LambdaExpression;

        if (lambda == null)

            throw new ArgumentNullException("method");

​

        MemberExpression memberExpr = null;

​

        if (lambda.Body.NodeType == ExpressionType.Convert)

        {

            memberExpr =

                ((UnaryExpression)lambda.Body).Operand as MemberExpression;

        }

        else if (lambda.Body.NodeType == ExpressionType.MemberAccess)

        {

            memberExpr = lambda.Body as MemberExpression;

        }

​

        if (memberExpr == null)

            throw new ArgumentException("method");

​

        return memberExpr;

    }

}