CA1041: Provide ObsoleteAttribute message
| Property | Value |
|---|---|
| Rule ID | CA1041 |
| Title | Provide ObsoleteAttribute message |
| Category | Design |
| Fix is breaking or non-breaking | Non-breaking |
| Enabled by default in .NET 9 | As suggestion |
Cause
A type or member is marked by using a System.ObsoleteAttribute attribute that does not have its System.ObsoleteAttribute.Message property specified.
By default, this rule only looks at externally visible types and members, but this is configurable.
Rule description
ObsoleteAttribute is used to mark deprecated library types and members. Library consumers should avoid the use of any type or member that is marked obsolete. This is because it might not be supported and will eventually be removed from later versions of the library. When a type or member marked by using ObsoleteAttribute is compiled, the Message property of the attribute is displayed. This gives the user information about the obsolete type or member. This information generally includes how long the obsolete type or member will be supported by the library designers and the preferred replacement to use.
How to fix violations
To fix a violation of this rule, add the message parameter to the ObsoleteAttribute constructor.
When to suppress warnings
Do not suppress a warning from this rule because the Message property provides critical information about the obsolete type or member.
Configure code to analyze
Use the following option to configure which parts of your codebase to run this rule on.
You can configure this option for just this rule, for all rules it applies to, or for all rules in this category (Design) that it applies to. For more information, see Code quality rule configuration options.
Include specific API surfaces
You can configure which parts of your codebase to run this rule on, based on their accessibility. For example, to specify that the rule should run only against the non-public API surface, add the following key-value pair to an .editorconfig file in your project:
dotnet_code_quality.CAXXXX.api_surface = private, internal
Example
The following example shows an obsolete member that has a correctly declared ObsoleteAttribute.
[ObsoleteAttribute("This property is obsolete and will be removed in a " +
"future version. Use the FullName property instead.", false)]
public string Name
{
get => "Name";
}
Imports System
Namespace ca1041
Public Class ObsoleteAttributeOnMember
<ObsoleteAttribute("This property is obsolete and will " &
"be removed in a future version. Use the FirstName " &
"and LastName properties instead.", False)>
ReadOnly Property Name As String
Get
Return "Name"
End Get
End Property
ReadOnly Property FirstName As String
Get
Return "FirstName"
End Get
End Property
ReadOnly Property LastName As String
Get
Return "LastName"
End Get
End Property
End Class
End Namespace
