find type of property with relection in C# [duplicate]

This question already has an answer here:

• How do I determine if a property is a user-defined type in C#? 5 answers

i have this model :

public class model
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Family { get; set; }
    public int RoleId { get; set; }
    public Role Role { get; set; }
}

public class Role
{
    public int RoleId { get; set; }
    public string RoleName { get; set; }
    public string SEC { get; set; }
}

i need search in the model and find propertys of type is Class but it can not find them .

i try by this code :

PropertyInfo[] props = model.GetType().GetProperties();
foreach (var item in props)
{
    if (item.PropertyType.IsClass)
    {
        PropertyInfo[] subClassProp = item.GetType().GetProperties();
        foreach (var itemB in subClassProp)
        {
            selectList.Add(itemB.Name);
        }
     }
}

How Can i Solve This Problem ?