DnsPermissionAttribute 类

定义

指定从域名服务器中请求信息的权限。Specifies permission to request information from Domain Name Servers.

public ref class DnsPermissionAttribute sealed : System::Security::Permissions::CodeAccessSecurityAttribute
[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)]
[System.Serializable]
public sealed class DnsPermissionAttribute : System.Security.Permissions.CodeAccessSecurityAttribute
type DnsPermissionAttribute = class
    inherit CodeAccessSecurityAttribute
Public NotInheritable Class DnsPermissionAttribute
Inherits CodeAccessSecurityAttribute
继承
属性

示例

下面的示例使用 DnsPermissionAttribute 向自定义类应用声明性安全。The following example uses DnsPermissionAttribute 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 ref class MyClass
{
public:
   static IPAddress^ GetIPAddress()
   {
      IPAddress^ ipAddress = Dns::Resolve( "localhost" )->AddressList[ 0 ];
      return ipAddress;
   }

};

int main()
{
   try
   {
      
      //Grants Access.
      Console::WriteLine( " Access granted\n The local host IP Address is :{0}", MyClass::GetIPAddress() );
   }
   // Denies Access.
   catch ( SecurityException^ securityException ) 
   {
      Console::WriteLine( "Access denied" );
      Console::WriteLine( securityException->ToString() );
   }

}

//Uses the DnsPermissionAttribute to restrict access only to those who have permission.
[DnsPermission(SecurityAction.Demand, Unrestricted = true)]
public class MyClass
{
    public static IPAddress GetIPAddress()
    {
        IPAddress ipAddress = Dns.Resolve("localhost").AddressList[0];
        return ipAddress;
    }
    public static void Main()
    {
        try
        {
            //Grants Access.
            Console.WriteLine(" Access granted\n The local host IP Address is :" + 
                                  MyClass.GetIPAddress().ToString());
        }
        // Denies Access.
        catch (SecurityException securityException)
        {
            Console.WriteLine("Access denied");	
            Console.WriteLine(securityException.ToString());
        }
' 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
End Class

注解

DnsPermissionAttribute 声明的安全信息存储在属性目标的元数据中,后者是应用 DnsPermissionAttribute 的类。The security information declared by DnsPermissionAttribute is stored in the metadata of the attribute target, which is the class to which the DnsPermissionAttribute is applied. 然后,系统会在运行时访问此信息。The system then accesses this information at run time. 传递给构造函数的 SecurityAction 确定允许的 DNS 目标。The SecurityAction that is passed to the constructor determines the allowable DNS targets.

这些安全特性仅用于声明性安全These security attributes are used only for Declarative Security. 对于命令性安全,请使用相应的 DnsPermission 类。For Imperative Security, use the corresponding DnsPermission class.

安全访问被完全限制或完全不受限制。Security access is either fully restricted or fully unrestricted. Unrestricted 属性设置为 true 授予访问权限,false 或设置为 "无访问权限"。Set the Unrestricted property to true to grant access, or false for no access. 将此属性设置为命名参数。Set this property as a named parameter.

有关使用特性的详细信息,请参阅特性For more information about using attributes, see Attributes.

构造函数

DnsPermissionAttribute(SecurityAction)

使用指定的 DnsPermissionAttribute 值初始化 SecurityAction 类的新实例。Initializes a new instance of the DnsPermissionAttribute class with the specified SecurityAction value.

属性

Action

获取或设置安全性操作。Gets or sets a security action.

(继承自 SecurityAttribute)
TypeId

在派生类中实现时,获取此 Attribute 的唯一标识符。When implemented in a derived class, gets a unique identifier for this Attribute.

(继承自 Attribute)
Unrestricted

获取或设置一个值,该值指示是否声明了对受该特性保护的资源有完全(无限制的)权限。Gets or sets a value indicating whether full (unrestricted) permission to the resource protected by the attribute is declared.

(继承自 SecurityAttribute)

方法

CreatePermission()

创建并返回 DnsPermission 类的新实例。Creates and returns a new instance of the DnsPermission class.

Equals(Object)

返回一个值,该值指示此实例是否与指定的对象相等。Returns a value that indicates whether this instance is equal to a specified object.

(继承自 Attribute)
GetHashCode()

返回此实例的哈希代码。Returns the hash code for this instance.

(继承自 Attribute)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
IsDefaultAttribute()

在派生类中重写时,指示此实例的值是否是派生类的默认值。When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(继承自 Attribute)
Match(Object)

当在派生类中重写时,返回一个指示此实例是否等于指定对象的值。When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(继承自 Attribute)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(继承自 Object)

显式接口实现

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

将一组名称映射为对应的一组调度标识符。Maps a set of names to a corresponding set of dispatch identifiers.

(继承自 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

检索对象的类型信息,然后可以使用该信息获取接口的类型信息。Retrieves the type information for an object, which can be used to get the type information for an interface.

(继承自 Attribute)
_Attribute.GetTypeInfoCount(UInt32)

检索对象提供的类型信息接口的数量(0 或 1)。Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(继承自 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

提供对某一对象公开的属性和方法的访问。Provides access to properties and methods exposed by an object.

(继承自 Attribute)

适用于

另请参阅