CA2239: Provide deserialization methods for optional fields
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The latest version of this topic can be found at CA2239: Provide deserialization methods for optional fields.
TypeName|ProvideDeserializationMethodsForOptionalFields|
|CheckId|CA2239|
|Category|Microsoft.Usage|
|Breaking Change|Non Breaking|
A type has a field that is marked with the System.Runtime.Serialization.OptionalFieldAttribute attribute and the type does not provide de-serialization event handling methods.
The OptionalFieldAttribute attribute has no effect on serialization; a field marked with the attribute is serialized. However, the field is ignored on de-serialization and retains the default value associated with its type. De-serialization event handlers should be declared to set the field during the de-serialization process.
To fix a violation of this rule, add de-serialization event handling methods to the type.
It is safe to suppress a warning from this rule if the field should be ignored during the de-serialization process.
The following example shows a type with an optional field and de-serialization event handling methods.
CA2236: Call base class methods on ISerializable types
CA2240: Implement ISerializable correctly
CA2229: Implement serialization constructors
CA2238: Implement serialization methods correctly
CA2235: Mark all non-serializable fields