The custom server control does not inherit the supportseventvalidation feature of the parent class/base class.

Author: failing Program Member-eight gods

Msdn does not mean that it cannot be inherited. In fact, it cannot be inherited.

You can see comments in the source code of the supportseventvalidationattribute class.
Note that this attribute does not inherit from the base class, since Derived classes may not be able to validate properly.

I prefer to see clear statements, such:
[Attributeusageattribute (attributetargets. Class, inherited =False, Allowmultiple =False)], And it does not declare this.

Let's take a look at the Declaration of the serializable feature, which makes it clear that it cannot be inherited, so we must include the declaration of this feature when writing the serialization class.

[Attributeusageattribute (attributetargets. Class | attributetargets. struct | attributetargets. Enum | attributetargets. Delegate, inherited =False)]

Public Sealed Class Serializableattribute: Attribute

This attribute is added in ASP. NET 2.0.
It is used to verify the validity of the data returned by the user control.
For example, the drop-down list box provides a one-to-31 day selection, but the client modifies the data
If a 32 value is submitted, the ASP. NET Framework throws an exception saying that the submitted data is invalid.
Many controls perform such verification, such as dropdownlist checkbox...
Develop custom controls. to verify data security, refer.