Specifies permission to request information from Domain Name Servers.
Assembly: System (in System.dll)
'Declaration <SerializableAttribute> _ <AttributeUsageAttribute(AttributeTargets.Assembly Or AttributeTargets.Class Or AttributeTargets.Struct Or AttributeTargets.Constructor Or AttributeTargets.Method, AllowMultiple := True, _ Inherited := False)> _ Public NotInheritable Class DnsPermissionAttribute _ Inherits CodeAccessSecurityAttribute
Thetype exposes the following members.
|Action||Gets or sets a security action. (Inherited from SecurityAttribute.)|
|TypeId||When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)|
|Unrestricted||Gets or sets a value indicating whether full (unrestricted) permission to the resource protected by the attribute is declared. (Inherited from SecurityAttribute.)|
|CreatePermission||Creates and returns a new instance of the DnsPermission class. (Overrides SecurityAttribute.CreatePermission.)|
|Equals||Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)|
|GetHashCode||Returns the hash code for this instance. (Inherited from Attribute.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|IsDefaultAttribute||When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)|
|Match||When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
|_Attribute.GetIDsOfNames||Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)|
|_Attribute.GetTypeInfo||Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)|
|_Attribute.GetTypeInfoCount||Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)|
|_Attribute.Invoke||Provides access to properties and methods exposed by an object. (Inherited from Attribute.)|
The security information declared by is stored in the metadata of the attribute target, which is the class to which the is applied. The system then accesses this information at run time. The SecurityAction that is passed to the constructor determines the allowable DNS targets.
Security access is either fully restricted or fully unrestricted. Set the Unrestricted property to true to grant access, or false for no access. Set this property as a named parameter.
For more information about using attributes, see Extending Metadata Using Attributes.
The following example uses to apply declarative security to a custom class.
' Uses the DnsPermissionAttribute to restrict access only to those who have permission. <DnsPermission(SecurityAction.Demand, Unrestricted := true)> _ Public Class MyClass1 Public Shared Function GetIPAddress() As IPAddress Dim ipAddress As IPAddress = Dns.Resolve("localhost").AddressList(0) Return ipAddress End Function 'GetIPAddress Public Shared Sub Main() Try ' Grants Access. Console.WriteLine(("Access granted" + ControlChars.NewLine + " The local host IP Address is :" + MyClass1.GetIPAddress().ToString())) ' Denies Access. Catch securityException As SecurityException Console.WriteLine("Access denied") Console.WriteLine(securityException.ToString()) End Try End Sub 'Main End Class '[MyClass1]
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.