Serialization event handlers that don’t have the correct signature will simply not be called, thus bypassing any attempts to augment the automated de/serialization.

This rule raises an issue when a method marked with one of the following attributes is public, static, does not return void, has type parameters, or does not have a single parameter of type System.Runtime.Serialization.StreamingContext:

• System.Runtime.Serialization.OnSerializingAttribute
• System.Runtime.Serialization.OnSerializedAttribute
• System.Runtime.Serialization.OnDeserializingAttribute
• System.Runtime.Serialization.OnDeserializedAttribute

Noncompliant Code Example

[Serializable]
public class Foo
{
    [OnSerializing]
    public void OnSerializing(StreamingContext context) {} // Noncompliant should be private

    [OnSerialized]
    int OnSerialized(StreamingContext context) {} // Noncompliant should return void

    [OnDeserializing]
    void OnDeserializing() {} // Noncompliant should have a single parameter of type StreamingContext

    [OnSerializing]
    public void OnSerializing2<T>(StreamingContext context) {} // Noncompliant should have no type parameters

    [OnDeserialized]
    void OnDeserialized(StreamingContext context, string str) {} // Noncompliant should have a single parameter of type StreamingContext
}

Compliant Solution

[Serializable]
public class Foo
{
    [OnSerializing]
    private void OnSerializing(StreamingContext context) {}

    [OnSerialized]
    private void OnSerialized(StreamingContext context) {}

    [OnDeserializing]
    private void OnDeserializing(StreamingContext context) {}

    [OnDeserialized]
    private void OnDeserialized(StreamingContext context) {}
}