IgnoreDataMember

IgnoreDataMember is an attribute used in the .NET framework to control data contract serialization. Defined in System.Runtime.Serialization, it marks a member of a data contract to be ignored by the DataContractSerializer and DataContractJsonSerializer. When a type is serialized as a data contract, members marked with IgnoreDataMember are excluded from the serialized output.

The attribute is applied to fields or properties. It is commonly used to omit sensitive information, large or transient data, or values that are derived at runtime and should not be persisted.

In typical data contract usage, a class is decorated with DataContract and the members intended for serialization are marked with DataMember. IgnoreDataMember provides a way to exclude a member, even in more complex inheritance or exposure scenarios where a member might otherwise be included.

Example:

[DataContract]

public class User

{

[DataMember]

public int Id { get; set; }

[DataMember]

public string UserName { get; set; }

[IgnoreDataMember]

public string Password { get; set; }

}

Limitations: IgnoreDataMember affects DataContractSerializer and related WCF JSON serialization. Other serialization frameworks (such as JSON.NET or BinaryFormatter) may not honor this attribute unless they explicitly recognize DataContract attributes.