Static holder types should be sealed
TypeName |
StaticHolderTypesShouldBeSealed |
CheckId |
CA1052 |
Category |
Microsoft.Design |
Breaking Change |
Breaking |
Cause
A public or protected type contains only static members and is not declared with the sealed (C# Reference) (NotInheritable) modifier.
Rule Description
This rule assumes that a type that contains only static members is not designed to be inherited, because the type does not provide any functionality that can be overridden in a derived type. A type that is not meant to be inherited should be marked with the sealed modifier to prohibit its use as a base type.
How to Fix Violations
To fix a violation of this rule, mark the type as sealed.
When to Exclude Warnings
Exclude a warning from this rule only if the type is designed to be inherited. The absence of the sealed modifier suggests that the type is useful as a base type.
Example
The following example shows a type that violates the rule.
Imports System
Namespace DesignLibrary
Public Class StaticMembers
Private Shared someField As Integer
Shared Property SomeProperty As Integer
Get
Return someField
End Get
Set
someField = Value
End Set
End Property
Private Sub New()
End Sub
Shared Sub SomeMethod()
End Sub
End Class
End Namespace
using System;
namespace DesignLibrary
{
public class StaticMembers
{
static int someField;
public static int SomeProperty
{
get
{
return someField;
}
set
{
someField = value;
}
}
StaticMembers() {}
public static void SomeMethod() {}
}
}
using namespace System;
namespace DesignLibrary
{
public ref class StaticMembers
{
static int someField;
StaticMembers() {}
public:
static property int SomeProperty
{
int get()
{
return someField;
}
void set(int value)
{
someField = value;
}
}
static void SomeMethod() {}
};
}