CodeAccessPermission 类  
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
注意
Code Access Security is not supported or honored by the runtime.
定义所有代码访问权限的基础结构。
public ref class CodeAccessPermission abstract : System::Security::IPermission, System::Security::IStackWalkpublic abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk[System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk[System.Serializable]
public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalk[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class CodeAccessPermission : System.Security.IPermission, System.Security.IStackWalktype CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk[<System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk[<System.Serializable>]
type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalk[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type CodeAccessPermission = class
    interface IPermission
    interface ISecurityEncodable
    interface IStackWalkPublic MustInherit Class CodeAccessPermission
Implements IPermission, IStackWalk- 继承
- 
				CodeAccessPermission
- 派生
- 属性
- 实现
示例
下面的代码示例显示了派生自 CodeAccessPermission 类的权限。
//#define debug
// This custom permission is intended only for the purposes of illustration.
// The following code shows how to create a custom permission that inherits
// from CodeAccessPermission. The code implements all required overrides.
// A wildcard character ('*') is implemented for the Name property.
using namespace System;
using namespace System::Security;
using namespace System::Security::Permissions;
using namespace System::IO;
using namespace System::Security::Policy;
using namespace System::Collections;
using namespace System::Text;
[assembly:System::Reflection::AssemblyKeyFile("Key.snk")];
[assembly:System::Security::AllowPartiallyTrustedCallersAttribute];
[Serializable]
public ref class NameIdPermission: public CodeAccessPermission, public IUnrestrictedPermission
{
private:
   String^ m_Name;
   bool m_Unrestricted;
public:
   NameIdPermission( String^ name )
   {
      m_Name = name;
   }
   NameIdPermission( PermissionState state )
   {
      if ( state == PermissionState::None )
      {
         m_Name = "";
      }
      else if ( state == PermissionState::Unrestricted )
      {
         throw gcnew ArgumentException( "Unrestricted state is not allowed for identity permissions." );
      }
      else
      {
         throw gcnew ArgumentException( "Invalid permission state." );
      }
   }
   property String^ Name 
   {
      String^ get()
      {
         return m_Name;
      }
      void set( String^ value )
      {
         m_Name = value;
      }
   }
public:
   virtual IPermission^ Copy() override
   {
      String^ name = m_Name;
      return gcnew NameIdPermission( name );
   }
public:
   virtual bool IsUnrestricted()
   {
      // Always false, unrestricted state is not allowed.
      return m_Unrestricted;
   }
private:
   bool VerifyType( IPermission^ target )
   {
      return dynamic_cast<NameIdPermission^>(target) != nullptr;
   }
public:
   virtual bool IsSubsetOf( IPermission^ target ) override
   {
#if ( debug ) 
      Console::WriteLine( "************* Entering IsSubsetOf *********************" );
#endif
      if ( target == nullptr )
      {
         Console::WriteLine( "IsSubsetOf: target == null" );
         return false;
      }
#if ( debug ) 
      Console::WriteLine( "This is = {0}", ((NameIdPermission)this).Name );
      Console::WriteLine( "Target is {0}", ((NameIdPermission)target).m_Name );
#endif
      try
      {
         NameIdPermission^ operand = dynamic_cast<NameIdPermission^>(target);
         
         // The following check for unrestricted permission is only included as an example for
         // permissions that allow the unrestricted state. It is of no value for this permission.
         if ( true == operand->m_Unrestricted )
         {
            return true;
         }
         else if ( true == this->m_Unrestricted )
         {
            return false;
         }
         if ( this->m_Name != nullptr )
         {
            if ( operand->m_Name == nullptr )
            {
               return false;
            }
            if ( this->m_Name->Equals( "" ) )
            {
               return true;
            }
         }
         if ( this->m_Name->Equals( operand->m_Name ) )
         {
            return true;
         }
         else
         {
            // Check for wild card character '*'.
            int i = operand->m_Name->LastIndexOf( "*" );
            if ( i > 0 )
            {
               String^ prefix = operand->m_Name->Substring( 0, i );
               if ( this->m_Name->StartsWith( prefix ) )
               {
                  return true;
               }
            }
         }
         return false;
      }
      catch ( InvalidCastException^ ) 
      {
         throw gcnew ArgumentException( String::Format( "Argument_WrongType", this->GetType()->FullName ) );
      }
   }
public:
   virtual IPermission^ Intersect( IPermission^ target ) override
   {
      Console::WriteLine( "************* Entering Intersect *********************" );
      if ( target == nullptr )
      {
         return nullptr;
      }
#if ( debug ) 
      Console::WriteLine( "This is = {0}", ((NameIdPermission)this).Name );
      Console::WriteLine( "Target is {0}", ((NameIdPermission)target).m_Name );
#endif 
      if (  !VerifyType( target ) )
      {
         throw gcnew ArgumentException( String::Format( "Argument is wrong type.", this->GetType()->FullName ) );
      }
      NameIdPermission^ operand = dynamic_cast<NameIdPermission^>(target);
      if ( operand->IsSubsetOf( this ) )
      {
         return operand->Copy();
      }
      else if ( this->IsSubsetOf( operand ) )
      {
         return this->Copy();
      }
      else
      {
         return nullptr;
      }
   }
public:
   virtual IPermission^ Union( IPermission^ target ) override
   {
#if ( debug ) 
      Console::WriteLine( "************* Entering Union *********************" );
#endif 
      if ( target == nullptr )
      {
         return this;
      }
#if ( debug ) 
      Console::WriteLine( "This is = {0}", ((NameIdPermission)this).Name );
      Console::WriteLine( "Target is {0}", ((NameIdPermission)target).m_Name );
#endif 
      if (  !VerifyType( target ) )
      {
         throw gcnew ArgumentException( String::Format( "Argument_WrongType", this->GetType()->FullName ) );
      }
      NameIdPermission^ operand = dynamic_cast<NameIdPermission^>(target);
      if ( operand->IsSubsetOf( this ) )
      {
         return this->Copy();
      }
      else if ( this->IsSubsetOf( operand ) )
      {
         return operand->Copy();
      }
      else
      {
         return nullptr;
      }
   }
public:
   virtual void FromXml( SecurityElement^ e ) override
   {
      // The following code for unrestricted permission is only included as an example for
      // permissions that allow the unrestricted state. It is of no value for this permission.
      String^ elUnrestricted = e->Attribute("Unrestricted");
      if ( nullptr != elUnrestricted )
      {
         m_Unrestricted = Boolean::Parse( elUnrestricted );
         return;
      }
      String^ elName = e->Attribute("Name");
      m_Name = elName == nullptr ? nullptr : elName;
   }
public:
   virtual SecurityElement^ ToXml() override
   {
      // Use the SecurityElement class to encode the permission to XML.
      SecurityElement^ esd = gcnew SecurityElement( "IPermission" );
      String^ name = NameIdPermission::typeid->AssemblyQualifiedName;
      esd->AddAttribute( "class", name );
      esd->AddAttribute( "version", "1.0" );
      
      // The following code for unrestricted permission is only included as an example for
      // permissions that allow the unrestricted state. It is of no value for this permission.
      if ( m_Unrestricted )
      {
         esd->AddAttribute( "Unrestricted", true.ToString() );
      }
      if ( m_Name != nullptr )
      {
         esd->AddAttribute( "Name", m_Name );
      }
      return esd;
   }
};
//#define debug
// This custom permission is intended only for the purposes of illustration.
// The following code shows how to create a custom permission that inherits
// from CodeAccessPermission. The code implements all required overrides.
// A wildcard character ('*') is implemented for the Name property.
using System;
using System.Security;
using System.Security.Permissions;
using System.IO;
using System.Security.Policy;
using System.Collections;
using System.Text;
[assembly:System.Reflection.AssemblyKeyFile("Key.snk")]
[assembly:System.Security.AllowPartiallyTrustedCallersAttribute()]
namespace MyPermission
{
    [Serializable()] sealed public class   NameIdPermission : CodeAccessPermission, IUnrestrictedPermission
    {
        private String m_Name;
        private bool m_Unrestricted;
        public  NameIdPermission(String name)
        {
            m_Name = name;
        }
        public  NameIdPermission(PermissionState state)
        {
            if (state == PermissionState.None)
            {
                m_Name = "";
            }
            else
                if (state == PermissionState.Unrestricted)
            {
                throw new ArgumentException("Unrestricted state is not allowed for identity permissions.");
            }
            else
            {
                throw new ArgumentException("Invalid permission state.");
            }
        }
        public String Name
        {
            set{m_Name = value;}
            get{ return m_Name;}
        }
        public override IPermission Copy()
        {
            string name = m_Name;
            return new  NameIdPermission( name );
        }
        public bool IsUnrestricted()
        {
            // Always false, unrestricted state is not allowed.
            return m_Unrestricted;
        }
        private bool VerifyType(IPermission target)
        {
            return (target is  NameIdPermission);
        }
        public override bool IsSubsetOf(IPermission target)
        {
#if(debug)
            Console.WriteLine ("************* Entering IsSubsetOf *********************");
#endif
            if (target == null)
            {
                Console.WriteLine ("IsSubsetOf: target == null");
                return false;
            }
#if(debug)
            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
#endif
            try
            {
                 NameIdPermission operand = ( NameIdPermission)target;
                // The following check for unrestricted permission is only included as an example for
                // permissions that allow the unrestricted state. It is of no value for this permission.
                if (true == operand.m_Unrestricted)
                {
                    return true;
                }
                else if (true == this.m_Unrestricted)
                {
                    return false;
                }
                if (this.m_Name != null)
                {
                    if (operand.m_Name == null) return false;
                    if (this.m_Name == "") return true;
                }
                if (this.m_Name.Equals (operand.m_Name))
                {
                    return true;
                }
                else
                {
                    // Check for wild card character '*'.
                    int i = operand.m_Name.LastIndexOf ("*");
                    if (i > 0)
                    {
                        string prefix = operand.m_Name.Substring (0, i);
                        if (this.m_Name.StartsWith (prefix))
                        {
                            return true;
                        }
                    }
                }
                return false;
            }
            catch (InvalidCastException)
            {
                throw new ArgumentException (String.Format ("Argument_WrongType", this.GetType ().FullName));
            }
        }
        public override IPermission Intersect(IPermission target)
        {
            Console.WriteLine ("************* Entering Intersect *********************");
            if (target == null)
            {
                return null;
            }
#if(debug)
            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
#endif
            if (!VerifyType(target))
            {
                throw new ArgumentException (String.Format ("Argument is wrong type.", this.GetType ().FullName));
            }
             NameIdPermission operand = ( NameIdPermission)target;
            if (operand.IsSubsetOf (this)) return operand.Copy ();
            else if (this.IsSubsetOf (operand)) return this.Copy ();
            else
                return null;
        }
        public override IPermission Union(IPermission target)
        {
#if(debug)
            Console.WriteLine ("************* Entering Union *********************");
#endif
            if (target == null)
            {
                return this;
            }
#if(debug)
            Console.WriteLine ("This is = " + (( NameIdPermission)this).Name);
            Console.WriteLine ("Target is " + (( NameIdPermission)target).m_Name);
#endif
            if (!VerifyType(target))
            {
                throw new ArgumentException (String.Format ("Argument_WrongType", this.GetType ().FullName));
            }
             NameIdPermission operand = ( NameIdPermission)target;
            if (operand.IsSubsetOf (this)) return this.Copy ();
            else if (this.IsSubsetOf (operand)) return operand.Copy ();
            else
                return null;
        }
        
        
        
        
       public override void FromXml(SecurityElement e)
        {
            // The following code for unrestricted permission is only included as an example for
            // permissions that allow the unrestricted state. It is of no value for this permission.
            String elUnrestricted = e.Attribute("Unrestricted");
            if (null != elUnrestricted)
            {
                m_Unrestricted = bool.Parse(elUnrestricted);
                return;
            }
            String elName = e.Attribute( "Name" );
            m_Name = elName == null ? null : elName;
        }
        public override SecurityElement ToXml()
        {
            // Use the SecurityElement class to encode the permission to XML.
            SecurityElement esd = new SecurityElement("IPermission");
            String name = typeof( NameIdPermission).AssemblyQualifiedName;
            esd.AddAttribute("class", name);
            esd.AddAttribute("version", "1.0");
            // The following code for unrestricted permission is only included as an example for
            // permissions that allow the unrestricted state. It is of no value for this permission.
            if (m_Unrestricted)
            {
                esd.AddAttribute("Unrestricted", true.ToString());
            }
            if (m_Name != null) esd.AddAttribute( "Name", m_Name );
            return esd;
        }
     }
}
' This custom permission is intended only for the purposes of illustration.
' The following code shows how to create a custom permission that inherits
' from CodeAccessPermission. The code implements all required overrides.
' A wildcard character ('*') is implemented for the Name property.
Imports System.Security
Imports System.Security.Permissions
Imports System.IO
Imports System.Security.Policy
Imports System.Collections
<assembly: System.Reflection.AssemblyKeyFile("Key.snk")>
<assembly: System.Security.AllowPartiallyTrustedCallersAttribute()>
Namespace MyPermission
    <Serializable()> _
                   Public NotInheritable Class NameIdPermission
        Inherits CodeAccessPermission
        Implements IUnrestrictedPermission
        Private m_Name As String
        Private m_Unrestricted As Boolean
        Public Sub New(ByVal name As String)
            m_name = name
        End Sub
        Public Sub New(ByVal state As PermissionState)
            If state = PermissionState.None Then
                m_name = ""
            ElseIf state = PermissionState.Unrestricted Then
                Throw New ArgumentException("Unrestricted state is not allowed for identity permissions.")
            Else
                Throw New ArgumentException("Invalid permission state.")
            End If
        End Sub
        Public Property Name() As String
            Get
                Return m_name
            End Get
            Set(ByVal Value As String)
                m_name = Value
            End Set
        End Property
        Public Overrides Function Copy() As IPermission
            Dim name As String
            name = m_name
            Return New NameIdPermission(name)
        End Function 'Copy
        Public Function IsUnrestricted() As Boolean Implements IUnrestrictedPermission.IsUnrestricted
            ' Always false, unrestricted state is not allowed.
            Return m_Unrestricted
        End Function
        Private Function VerifyType(ByVal target As IPermission) As Boolean
            Return TypeOf target Is NameIdPermission
        End Function 'VerifyType
        Public Overrides Function IsSubsetOf(ByVal target As IPermission) As Boolean
#If (Debug) Then
            Console.WriteLine("************* Entering IsSubsetOf *********************")
#End If
            If target Is Nothing Then
                Console.WriteLine("IsSubsetOf: target == null")
                Return False
            End If
#If (Debug) Then
            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If
            Try
                Dim operand As NameIdPermission = CType(target, NameIdPermission)
                ' The following check for unrestricted permission is only included as an example for
                ' permissions that allow the unrestricted state. It is of no value for this permission.
                If True = operand.m_Unrestricted Then
                    Return True
                ElseIf True = Me.m_Unrestricted Then
                    Return False
                End If
                If Not (Me.m_name Is Nothing) Then
                    If operand.m_name Is Nothing Then
                        Return False
                    End If
                    If Me.m_name = "" Then
                        Return True
                    End If
                End If
                If Me.m_name.Equals(operand.m_name) Then
                    Return True
                Else
                    ' Check for wild card character '*'.
                    Dim i As Integer = operand.m_name.LastIndexOf("*")
                    If i > 0 Then
                        Dim prefix As String = operand.m_name.Substring(0, i)
                        If Me.m_name.StartsWith(prefix) Then
                            Return True
                        End If
                    End If
                End If
                Return False
            Catch
                Throw New ArgumentException(String.Format("Argument_WrongType", Me.GetType().FullName))
            End Try
        End Function
        Public Overrides Function Intersect(ByVal target As IPermission) As IPermission
            Console.WriteLine("************* Entering Intersect *********************")
            If target Is Nothing Then
                Return Nothing
            End If
#If (Debug) Then
            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If
            If Not VerifyType(target) Then
                Throw New ArgumentException(String.Format("Argument is wrong type.", Me.GetType().FullName))
            End If
            Dim operand As NameIdPermission = CType(target, NameIdPermission)
            If operand.IsSubsetOf(Me) Then
                Return operand.Copy()
            ElseIf Me.IsSubsetOf(operand) Then
                Return Me.Copy()
            Else
                Return Nothing
            End If
        End Function 'Intersect
        Public Overrides Function Union(ByVal target As IPermission) As IPermission
#If (Debug) Then
            Console.WriteLine("************* Entering Union *********************")
#End If
            If target Is Nothing Then
                Return Me
            End If
#If (Debug) Then
            Console.WriteLine(("This is = " + CType(Me, NameIdPermission).Name))
            Console.WriteLine(("Target is " + CType(target, NameIdPermission).m_name))
#End If
            If Not VerifyType(target) Then
                Throw New ArgumentException(String.Format("Argument_WrongType", Me.GetType().FullName))
            End If
            Dim operand As NameIdPermission = CType(target, NameIdPermission)
            If operand.IsSubsetOf(Me) Then
                Return Me.Copy()
            ElseIf Me.IsSubsetOf(operand) Then
                Return operand.Copy()
            Else
                Return Nothing
            End If
        End Function 'Union
        Public Overrides Sub FromXml(ByVal e As SecurityElement)
            ' The following code for unrestricted permission is only included as an example for
            ' permissions that allow the unrestricted state. It is of no value for this permission.
            Dim elUnrestricted As String = e.Attribute("Unrestricted")
            If Nothing <> elUnrestricted Then
                m_Unrestricted = Boolean.Parse(elUnrestricted)
                Return
            End If
            Dim elName As String = e.Attribute("Name")
            m_name = IIf(elName Is Nothing, Nothing, elName)
        End Sub
        Public Overrides Function ToXml() As SecurityElement
            ' Use the SecurityElement class to encode the permission to XML.
            Dim esd As New SecurityElement("IPermission")
            Dim name As String = GetType(NameIdPermission).AssemblyQualifiedName
            esd.AddAttribute("class", name)
            esd.AddAttribute("version", "1.0")
            ' The following code for unrestricted permission is only included as an example for
            ' permissions that allow the unrestricted state. It is of no value for this permission.
            If m_Unrestricted Then
                esd.AddAttribute("Unrestricted", True.ToString())
            End If
            If Not (m_Name Is Nothing) Then
                esd.AddAttribute("Name", m_Name)
            End If
            Return esd
        End Function 'ToXml
    End Class
End Namespace
注解
注意
代码访问安全性 (CAS) 已在所有版本的 .NET Framework 和 .NET 中弃用。 如果使用与 CAS 相关的 API,最新版本的 .NET 不会遵循 CAS 注释,并会生成错误。 开发人员应寻求用于完成安全任务的替代方法。
代码访问权限使用堆栈遍历来确保向代码的所有调用方授予权限。 如果权限对象为 null,则其处理方式与状态 PermissionState.None为 的权限对象相同。
调用堆栈通常表示为向下增长,因此调用堆栈中较高方法调用调用堆栈中较低的方法。
必须向 类的 CodeAccessPermission 继承者授予完全信任,才能作为扩展安全基础结构的权限正常运行。 若要确定继承者是完全受信任的,CodeAccessPermission请为 ControlEvidencetrue = 和 ControlPolicytrue = 发出 。InheritanceDemand
实施者说明
从 CodeAccessPermission继承时,还必须实现 IUnrestrictedPermission 接口。
必须重写以下CodeAccessPermission成员:Copy()、、Intersect(IPermission)、IsSubsetOf(IPermission)ToXml()、 FromXml(SecurityElement)和 Union(IPermission)。
还必须定义采用 作为其唯一参数的构造函数 PermissionState 。
必须将 特性 SerializableAttribute 应用于继承自 CodeAccessPermission的类。
构造函数
| CodeAccessPermission() | 
				已过时.
			 初始化 CodeAccessPermission 类的新实例。 | 
方法
| Assert() | 
				已过时.
			 声明调用代码能够通过调用此方法的代码,访问受权限请求保护的资源,即使未对堆栈中处于较高位置的调用方授予访问该资源的权限。 使用 Assert() 会引起安全问题。 | 
| Copy() | 
				已过时.
			 由派生类实现时,创建并返回当前权限对象的相同副本。 | 
| Demand() | 
				已过时.
			 如果未对调用堆栈中处于较高位置的所有调用方授予当前实例所指定的权限,则在运行时强制 SecurityException。 | 
| Deny() | 
				已过时.
			 
				已过时.
			 防止处于调用堆栈较高位置的调用函数使用可以调用此方法来访问当前实例指定资源的代码。 | 
| Equals(Object) | 
				已过时.
			 确定指定的 CodeAccessPermission 对象是否等于当前的 CodeAccessPermission。 | 
| Equals(Object) | 
		已过时.
	 确定指定对象是否等于当前对象。(继承自 Object) | 
| FromXml(SecurityElement) | 
				已过时.
			 当在派生类中替代时,用 XML 编码重新构造具有指定状态的安全对象。 | 
| GetHashCode() | 
				已过时.
			 获取 CodeAccessPermission 对象的哈希代码,此代码适合在哈希算法和数据结构(例如哈希表)中使用。 | 
| GetHashCode() | 
		已过时.
	 作为默认哈希函数。(继承自 Object) | 
| GetType() | 
		已过时.
	 获取当前实例的 Type。(继承自 Object) | 
| Intersect(IPermission) | 
				已过时.
			 通过派生类实现时,创建和返回是当前权限和指定权限的交集的权限。 | 
| IsSubsetOf(IPermission) | 
				已过时.
			 通过派生类实现时,确定当前权限是否为指定权限的子集。 | 
| MemberwiseClone() | 
		已过时.
	 创建当前 Object 的浅表副本。(继承自 Object) | 
| PermitOnly() | 
				已过时.
			 防止处于调用堆栈较高位置的调用函数使用此代码,此代码将调用此方法来访问除当前实例指定的资源以外的所有资源。 | 
| RevertAll() | 
				已过时.
			 导致当前帧以前所有的重写被删除且不再有效。 | 
| RevertAssert() | 
				已过时.
			 导致当前帧以前所有的 Assert() 被删除且不再有效。 | 
| RevertDeny() | 
				已过时.
			 
				已过时.
			 导致当前帧以前所有的 Deny() 被删除且不再有效。 | 
| RevertPermitOnly() | 
				已过时.
			 导致当前帧以前所有的 PermitOnly() 被删除且不再有效。 | 
| ToString() | 
				已过时.
			 创建并返回当前权限对象的字符串表示形式。 | 
| ToXml() | 
				已过时.
			 当在派生类中重写时,创建安全对象及其当前状态的 XML 编码。 | 
| Union(IPermission) | 
				已过时.
			 当在派生类中重写时,则创建属于当前权限与指定权限的并集的权限。 |