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CA1030: Use events where appropriate

  • Article

Note

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Item Value
TypeName UseEventsWhereAppropriate
CheckId CA1030
Category Microsoft.Design
Breaking Change Non-breaking

Cause

A public, protected, or private method name begins with one of the following:

  • AddOn

  • RemoveOn

  • Fire

  • Raise

Rule Description

This rule detects methods that have names that ordinarily would be used for events. Events follow the Observer or Publish-Subscribe design pattern; they are used when a state change in one object must be communicated to other objects. If a method gets called in response to a clearly defined state change, the method should be invoked by an event handler. Objects that call the method should raise events instead of calling the method directly.

Some common examples of events are found in user interface applications where a user action such as clicking a button causes a segment of code to execute. The .NET Framework event model is not limited to user interfaces; it should be used anywhere you must communicate state changes to one or more objects.

How to Fix Violations

If the method is called when the state of an object changes, you should consider changing the design to use the .NET Framework event model.

When to Suppress Warnings

Suppress a warning from this rule if the method does not work with the .NET Framework event model.