Ignore Non Serialized property in BinaryFormatter Serialization

Question

I have a class called Userand it is [Serializable] and inherited from base class IdentityUser an Entity Framework class and Non Serializab

Answer 1

BinaryFormatter serializes the public and private fields of a object -- not the properties. For an auto-implemented property the secret backing field is what is actually serialized.

Normally, if you do not want a field to be serialized, you can apply the [NonSerialized] attribute, and BinaryFormatter will skip it. In c# 7.3 and later, it's possible to do this to the secret backing field of an auto-implemented property by using a field-targeted attribute:

    [field: NonSerialized]
    public virtual User Guest { set; get; }

See: Auto-Implemented Property Field-Targeted Attributes and What's new in C# 7.3.

Prior to c# 7.3 there is no way to apply an attribute to the backing field of an auto-implemented property. Thus you need to make the backing field be explicit:

[Serializable]
public class Booking
{
    [ForeignKey("Guest")]
    public string GuestId { set; get; }

    [NonSerialized]
    User guest;

    public virtual User Guest { set { guest = value; } get { return guest; } }
}

Incidentally, if you need to serialize some of the information in User, you could consider implementing ISerializable, or replacing instances of User with serialization surrogates.