The scope of the declaration that is allowed depends on the SecurityAction that is used.

The security information declared by a security attribute is stored in the metadata of the attribute target and is accessed by the system at run time. Security attributes are used only for declarative security. For imperative security, use the corresponding permission class.

When you use the SecurityPermissionAttribute class, follow the security action with the permission(s) that are being requested. Each security permission that can be requested, as defined in the SecurityPermissionFlag enumeration, has a corresponding property in the SecurityPermissionAttribute class. For example, to demand the ability to access unmanaged code, follow the demand statement with the property setting that is being requested, as follows: SecurityPermissionAttribute(SecurityAction.Demand, UnmanagedCode=true).

Note:
An exception to the equivalence between the SecurityPermissionFlag enumeration and the SecurityPermissionAttribute properties is that the AllFlags enumeration value is represented by the Unrestricted property (inherited from the SecurityAttribute class). To demand all security permissions, specify Unrestricted=true.

The following example of a declarative attribute shows the correct way to request SecurityPermission for the ability to assert and states that you must have at least this permission to run your code.

 <Assembly:SecurityPermissionAttribute(SecurityAction.RequestMinimum, _
 Assertion := True)>
'In Visual Basic, you must specify that you are using the assembly scope when making a request.

[assembly:SecurityPermissionAttribute(SecurityAction.RequestMinimum, Assertion=true)]
//In C#, you must specify that you are using the assembly scope when making a request.

[assembly:SecurityPermissionAttribute(SecurityAction::RequestMinimum,Assertion=true)];
//In C++, you must specify that you are using the assembly scope when making a request.

The following example shows how to demand that the calling code has SecurityPermission at link time. Demands are typically made in managed libraries (DLLs) to help protect methods or classes from potentially harmful code.

   <SecurityPermissionAttribute(SecurityAction.LinkDemand, _
Unrestricted:=True)> Public Class SampleClass

[SecurityPermissionAttribute(SecurityAction.LinkDemand, Unrestricted=true)]

[SecurityPermissionAttribute(SecurityAction::LinkDemand,Unrestricted=true)]

For a complete example showing how to create instances of the SecurityPermissionAttribute class that are used to deny and demand security permissions see the SecurityPermissionAttribute constructor.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework

Reference

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