CA2236: Call base class methods on ISerializable types

Cause

A type derives from a type that implements the ISerializable interface, and one of the following conditions is true:

• The type implements the serialization constructor, that is, a constructor with the SerializationInfo, StreamingContext parameter signature, but does not call the serialization constructor of the base type.

• The type implements the ISerializable.GetObjectData method but does not call the GetObjectData method of the base type.

Rule Description

In a custom serialization process, a type implements the GetObjectData method to serialize its fields and the serialization constructor to de-serialize the fields. If the type derives from a type that implements the ISerializable interface, the base type GetObjectData method and serialization constructor should be called to serialize/de-serialize the fields of the base type. Otherwise, the type will not be serialized and de-serialized correctly. Note that if the derived type does not add any new fields, the type does not need to implement the GetObjectData method nor the serialization constructor or call the base type equivalents.

How to Fix Violations

To fix a violation of this rule, call the base type GetObjectData method or serialization constructor from the corresponding derived type method or constructor.

When to Suppress Warnings

Do not suppress a warning from this rule.

Example

The following example shows a derived type that satisfies the rule by calling the serialization constructor and GetObjectData method of the base class.

Imports System
Imports System.Runtime.Serialization
Imports System.Security.Permissions

Namespace UsageLibrary

   <SerializableAttribute> _ 
   Public Class BaseType
      Implements ISerializable

      Dim baseValue As Integer 

      Sub New()
         baseValue = 3
      End Sub 

      Protected Sub New( _ 
         info As SerializationInfo, context As StreamingContext)

         baseValue = info.GetInt32("baseValue")

      End Sub

      <SecurityPermissionAttribute(SecurityAction.Demand, _ 
          SerializationFormatter := True)> _ 
      Overridable Sub GetObjectData( _ 
         info As SerializationInfo, context As StreamingContext) _ 
         Implements ISerializable.GetObjectData

         info.AddValue("baseValue", baseValue)

      End Sub 

   End Class

   <SerializableAttribute> _ 
   Public Class DerivedType: Inherits BaseType

      Dim derivedValue As Integer 

      Sub New()
         derivedValue = 4
      End Sub 

      Protected Sub New( _ 
         info As SerializationInfo, context As StreamingContext)

         MyBase.New(info, context)      
         derivedValue = info.GetInt32("derivedValue")

      End Sub

      <SecurityPermissionAttribute(SecurityAction.Demand, _ 
          SerializationFormatter := True)> _ 
      Overrides Sub GetObjectData( _ 
         info As SerializationInfo, context As StreamingContext)

         info.AddValue("derivedValue", derivedValue)
         MyBase.GetObjectData(info, context)

      End Sub 

   End Class 

End Namespace

using System;
using System.Runtime.Serialization;
using System.Security.Permissions;

namespace UsageLibrary
{
   [SerializableAttribute]
   public class BaseType : ISerializable
   {
      int baseValue;

      public BaseType()
      {
         baseValue = 3;
      }

      protected BaseType(
         SerializationInfo info, StreamingContext context)
      {
         baseValue = info.GetInt32("baseValue");
      }

      [SecurityPermissionAttribute(SecurityAction.Demand, 
          SerializationFormatter = true)]
      public virtual void GetObjectData(
         SerializationInfo info, StreamingContext context)
      {
         info.AddValue("baseValue", baseValue);
      }
   }

   [SerializableAttribute]
   public class DerivedType : BaseType
   {
      int derivedValue;

      public DerivedType()
      {
         derivedValue = 4;
      }

      protected DerivedType(
         SerializationInfo info, StreamingContext context) : 
         base(info, context)
      {
         derivedValue = info.GetInt32("derivedValue");
      }

      [SecurityPermissionAttribute(SecurityAction.Demand, 
          SerializationFormatter = true)]
      public override void GetObjectData(
         SerializationInfo info, StreamingContext context)
      {
         info.AddValue("derivedValue", derivedValue);
         base.GetObjectData(info, context);
      }
   }
}

Related Rules

CA2240: Implement ISerializable correctly

CA2229: Implement serialization constructors

CA2238: Implement serialization methods correctly

CA2235: Mark all non-serializable fields

CA2237: Mark ISerializable types with SerializableAttribute

CA2239: Provide deserialization methods for optional fields

CA2120: Secure serialization constructors