CA2229: Implement serialization constructors

 

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The latest version of this topic can be found at CA2229: Implement serialization constructors.

TypeName|ImplementSerializationConstructors|
|CheckId|CA2229|
|Category|Microsoft.Usage|
|Breaking Change|Non Breaking|

The type implements the System.Runtime.Serialization.ISerializable interface, is not a delegate or interface, and one of the following conditions is true:

This rule is relevant for types that support custom serialization. A type supports custom serialization if it implements the ISerializable interface. The serialization constructor is required to deserialize, or re-create objects that have been serialized using the ISerializable.GetObjectData method.

To fix a violation of this rule, implement the serialization constructor. For a sealed class, make the constructor private; otherwise, make it protected.

Do not suppress a violation of the rule. The type will not be deserializable, and will not function in many scenarios.

The following example shows a type that satisfies the rule.

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Security.Permissions;

namespace UsageLibrary 
{   
    [Serializable]
    public class SerializationConstructorsRequired : ISerializable 
    {
        private  int n1;

        // This is a regular constructor.
        public SerializationConstructorsRequired ()
        {
            n1 = -1;
        }
        // This is the serialization constructor.
        // Satisfies rule: ImplementSerializationConstructors.

        protected SerializationConstructorsRequired(
           SerializationInfo info, 
           StreamingContext context)
        {
            n1 = (int) info.GetValue("n1", typeof(int));
        }

        // The following method serializes the instance.
        [SecurityPermission(SecurityAction.LinkDemand, 
            Flags=SecurityPermissionFlag.SerializationFormatter)]
        void ISerializable.GetObjectData(SerializationInfo info, 
           StreamingContext context)
        {
            info.AddValue("n1", n1);
        }
    }
}

CA2237: Mark ISerializable types with SerializableAttribute

System.Runtime.Serialization.ISerializable
System.Runtime.Serialization.SerializationInfo
System.Runtime.Serialization.StreamingContext

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