HostProtectionAttribute 类

定义

public ref class HostProtectionAttribute sealed : System::Security::Permissions::CodeAccessSecurityAttribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Delegate | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)]
[System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public sealed class HostProtectionAttribute : System.Security.Permissions.CodeAccessSecurityAttribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Delegate | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)]
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public sealed class HostProtectionAttribute : System.Security.Permissions.CodeAccessSecurityAttribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Delegate | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)]
public sealed class HostProtectionAttribute : System.Security.Permissions.CodeAccessSecurityAttribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Delegate | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)>]
[<System.Obsolete("Code Access Security is not supported or honored by the runtime.", DiagnosticId="SYSLIB0003", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
type HostProtectionAttribute = class
    inherit CodeAccessSecurityAttribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Delegate | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
[<System.Serializable>]
type HostProtectionAttribute = class
    inherit CodeAccessSecurityAttribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Constructor | System.AttributeTargets.Delegate | System.AttributeTargets.Method | System.AttributeTargets.Struct, AllowMultiple=true, Inherited=false)>]
type HostProtectionAttribute = class
    inherit CodeAccessSecurityAttribute

Public NotInheritable Class HostProtectionAttribute
Inherits CodeAccessSecurityAttribute

继承

Object

Attribute

SecurityAttribute

CodeAccessSecurityAttribute

HostProtectionAttribute

属性

AttributeUsageAttribute ObsoleteAttribute ComVisibleAttribute SerializableAttribute

示例

下面的代码示例演示如何使用 HostProtectionAttribute 具有各种值的属性 HostProtectionResource 。

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::IO;
using namespace System::Threading;
using namespace System::Security;
using namespace System::Security::Policy;
using namespace System::Security::Principal;
using namespace System::Security::Permissions;
using namespace System::Diagnostics;
using namespace System::ComponentModel;
using namespace System::Windows::Forms;
using namespace System::Security::Permissions;

// The following class is an example of code that exposes external process management.
// Add the LicenseProviderAttribute to the control.

[LicenseProvider(LicFileLicenseProvider::typeid)]
public ref class MyControl: public System::Windows::Forms::Control
{
private:

   // Create a new, null license.
   License^ license;

public:
   [HostProtection(ExternalProcessMgmt=true)]
   MyControl()
   {
      license = nullptr;
      
      // Determine if a valid license can be granted.
      bool isValid = LicenseManager::IsValid( MyControl::typeid );
      Console::WriteLine( "The result of the IsValid method call is {0}", isValid );
   }

};

// If this application is run on a server that implements host protection, the HostProtection attribute  
// is applied. If the application is run on a server that is not host-protected, the attribute 
// evaporates; it is not detected and therefore not applied. HostProtection can be configured with 
// members of the HostProtectionResource enumeration to customize the protection offered. 
// The primary intent of this sample is to show situations in which the HostProtection attribute
// might be meaningfully used.  The environment required to demonstrate a particular HostProtection is
// too complex to invoke within the scope of this sample.
public ref class HostProtectionExample
{
public:
   static int Success = 100;

private:

   // Use the enumeration flags to indicate that this method exposes shared state and 
   // self-affecting process management.
   // Either of the following attribute statements can be used to set the 
   // resource flags.
   // Exit the sample when an exception is thrown.

   [HostProtection(SharedState=true,SelfAffectingProcessMgmt=true)]
   [HostProtection(Resources=HostProtectionResource::SharedState|
   HostProtectionResource::SelfAffectingProcessMgmt)]
   static void Exit( String^ Message, int Code )
   {
      Console::WriteLine( "\nFAILED: {0} {1}", Message, Code );
      Environment::ExitCode = Code;
      Environment::Exit( Code );
   }

   // Use the enumeration flags to indicate that this method exposes shared state, 
   // self-affecting process management, and self-affecting threading.
   // This method allows the user to quit the sample.

   [HostProtection(SharedState=true,SelfAffectingProcessMgmt=true,
   SelfAffectingThreading=true,UI=true)]
   static void ExecuteBreak()
   {
      Console::WriteLine( "Executing Debugger.Break." );
      Debugger::Break();
      Debugger::Log( 1, "info", "test message" );
   }

   // Use the enumeration flags to indicate that this method exposes shared state, 
   // self-affecting threading and the security infrastructure.
   // ApplyIdentity sets the current identity.

   [HostProtection(SharedState=true,SelfAffectingThreading=true,
   SecurityInfrastructure=true)]
   static int ApplyIdentity()
   {
      array<String^>^roles = {"User"};
      try
      {
         AppDomain^ mAD = AppDomain::CurrentDomain;
         GenericPrincipal^ mGenPr = gcnew GenericPrincipal( WindowsIdentity::GetCurrent(),roles );
         mAD->SetPrincipalPolicy( PrincipalPolicy::WindowsPrincipal );
         mAD->SetThreadPrincipal( mGenPr );
         return Success;
      }
      catch ( Exception^ e ) 
      {
         Exit( e->ToString(), 5 );
      }

      return 0;
   }

public:

   // The following method is started on a separate thread.
   [PermissionSet(SecurityAction::Demand, Name="FullTrust")]
   static void WatchFileEvents()
   {
      try
      {
         Console::WriteLine( "In the child thread." );
         FileSystemWatcher^ watcher = gcnew FileSystemWatcher;
         watcher->Path = "C:\\Temp";
         
         // Watch for changes in LastAccess and LastWrite times, and 
         // name changes to files or directories. 
         watcher->NotifyFilter = static_cast<NotifyFilters>(NotifyFilters::LastAccess | NotifyFilters::LastWrite | NotifyFilters::FileName | NotifyFilters::DirectoryName);
         
         // Watch only text files.
         watcher->Filter = "*.txt";
         
         // Add event handlers.
         watcher->Changed += gcnew FileSystemEventHandler( OnChanged );
         watcher->Created += gcnew FileSystemEventHandler( OnChanged );
         watcher->Deleted += gcnew FileSystemEventHandler( OnChanged );
         
         // Begin watching.
         watcher->EnableRaisingEvents = true;
         
         // Wait for the user to quit the program.
         Console::WriteLine( "Event handlers have been enabled." );
         while ( Console::Read() != 'q' )
                  ;
      }
      catch ( Exception^ e ) 
      {
         Console::WriteLine( e->Message );
      }

   }


private:

   // Use the enumeration flags to indicate that this method exposes synchronization 
   //  and external threading.

   [HostProtection(Synchronization=true,ExternalThreading=true)]
   static void StartThread()
   {
      Thread^ t = gcnew Thread( gcnew ThreadStart( WatchFileEvents ) );
      
      // Start the new thread.  On a uniprocessor, the thread is not given 
      // any processor time until the main thread yields the processor.  
      t->Start();
      
      // Give the new thread a chance to execute.
      Thread::Sleep( 1000 );
   }

public:

   // Call methods that show the use of the HostProtectionResource enumeration.
   [HostProtection(Resources=HostProtectionResource::All)]
   static int Main()
   {
      try
      {
         
         // Show use of the HostProtectionResource.SharedState,
         //   HostProtectionResource.SelfAffectingThreading, and
         //   HostProtectionResource.Security enumeration values.
         ApplyIdentity();
         Directory::CreateDirectory( "C:\\Temp" );
         
         // Show use of the HostProtectionResource.Synchronization and
         //   HostProtectionResource.ExternalThreading enumeration values.
         StartThread();
         Console::WriteLine( "In the main thread." );
         Console::WriteLine( "Deleting and creating 'MyTestFile.txt'." );
         if ( File::Exists( "C:\\Temp\\MyTestFile.txt" ) )
         {
            File::Delete( "C:\\Temp\\MyTestFile.txt" );
         }
         StreamWriter^ sr = File::CreateText( "C:\\Temp\\MyTestFile.txt" );
         sr->WriteLine( "This is my file." );
         sr->Close();
         Thread::Sleep( 1000 );
         
         // Show use of the HostProtectionResource.SharedState,
         //   HostProtectionResource.SelfProcessMgmt,
         //   HostProtectionResource.SelfAffectingThreading, and
         //   HostProtectionResource.UI enumeration values.
         ExecuteBreak();
         
         // Show the use of the HostProtectionResource.ExternalProcessManagement enumeration value.
         MyControl^ myControl = gcnew MyControl;
         Console::WriteLine( "Enter 'q' to quit the sample." );
         return 100;
      }
      catch ( Exception^ e ) 
      {
         Exit( e->ToString(), 0 );
         return 0;
      }
   }

   // Define the event handlers.
   private:
   static void OnChanged( Object^ /*source*/, FileSystemEventArgs^ e )
   {
      
      // Specify whether a file is changed, created, or deleted.
      Console::WriteLine( "In the OnChanged event handler." );
      Console::WriteLine( "File: {0} {1}", e->FullPath, e->ChangeType );
   }

};

int main()
{
   return HostProtectionExample::Main();
}

using System;
using System.IO;
using System.Threading;
using System.Security;
using System.Security.Policy;
using System.Security.Principal;
using System.Security.Permissions;
using System.Diagnostics;
using System.ComponentModel;
using System.Windows.Forms;

// If this application is run on a server that implements host protection, the 
// HostProtectionAttribute attribute is applied. If the application is run on   
// a server that is not host-protected, the attribute evaporates; it is not  
// detected and therefore not applied. Host protection can be configured with  
// members of the HostProtectionResource enumeration to customize the  
// protection offered.
// The primary intent of this sample is to show situations in which the 
// HostProtectionAttribute attribute might be meaningfully used. The  
// environment required to demonstrate a particular behavior is
// too complex to invoke within the scope of this sample.

class HostProtectionExample
{
    public static int Success = 100;
    
    // Use the enumeration flags to indicate that this method exposes 
    // shared state and self-affecting process management.
    // Either of the following attribute statements can be used to set the
    // resource flags.
    [HostProtectionAttribute(SharedState = true, 
        SelfAffectingProcessMgmt = true)]
    [HostProtectionAttribute(Resources = HostProtectionResource.SharedState |
         HostProtectionResource.SelfAffectingProcessMgmt)]
    private static void Exit(string Message, int Code)
    {
        // Exit the sample when an exception is thrown.
        Console.WriteLine("\nFAILED: " + Message + " " + Code.ToString());
        Environment.ExitCode = Code;
        Environment.Exit(Code);
    }

    // Use the enumeration flags to indicate that this method exposes shared 
    // state, self-affecting process management, and self-affecting threading.
    [HostProtectionAttribute(SharedState=true, SelfAffectingProcessMgmt=true,
         SelfAffectingThreading=true, UI=true)]
    // This method allows the user to quit the sample.
    private static void ExecuteBreak()
    {
        Console.WriteLine("Executing Debugger.Break.");
        Debugger.Break();
        Debugger.Log(1,"info","test message");
    }
    
    // Use the enumeration flags to indicate that this method exposes shared 
    // state, self-affecting threading, and the security infrastructure.
    [HostProtectionAttribute(SharedState=true, SelfAffectingThreading=true,
         SecurityInfrastructure=true)]
    // ApplyIdentity sets the current identity.
    private static int ApplyIdentity()
    {
        string[] roles = {"User"};
        try
        {
            AppDomain mAD = AppDomain.CurrentDomain;
            GenericPrincipal mGenPr = 
                new GenericPrincipal(WindowsIdentity.GetCurrent(), roles);
            mAD.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);
            mAD.SetThreadPrincipal(mGenPr);
            return Success;
        }
        catch (Exception e)
        {
            Exit(e.ToString(), 5);
        }
        return 0;
    }

    // The following method is started on a separate thread.
    public static void WatchFileEvents()
    {
        try
        {
            Console.WriteLine("In the child thread.");
            FileSystemWatcher watcher = new FileSystemWatcher();
            watcher.Path = "C:\\Temp";
            
            // Watch for changes in LastAccess and LastWrite times, and
            // name changes to files or directories.
            watcher.NotifyFilter = NotifyFilters.LastAccess 
                | NotifyFilters.LastWrite
                | NotifyFilters.FileName | NotifyFilters.DirectoryName;
            
            // Watch only text files.
            watcher.Filter = "*.txt";

            // Add event handlers.
            watcher.Changed += new FileSystemEventHandler(OnChanged);
            watcher.Created += new FileSystemEventHandler(OnChanged);
            watcher.Deleted += new FileSystemEventHandler(OnChanged);
            
            // Begin watching.
            watcher.EnableRaisingEvents = true;

            // Wait for the user to quit the program.
            Console.WriteLine("Event handlers have been enabled.");
            while(Console.Read()!='q');
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
    }

    // Use the enumeration flags to indicate that this method exposes 
    // synchronization and external threading.
    [HostProtectionAttribute(Synchronization=true, ExternalThreading=true)]
    private static void StartThread()
    {
        Thread t = new Thread(new ThreadStart(WatchFileEvents));
        
        // Start the new thread. On a uniprocessor, the thread is not given
        // any processor time until the main thread yields the processor.
        t.Start();
        
        // Give the new thread a chance to execute.
        Thread.Sleep(1000);
    }

    // Call methods that show the use of the HostProtectionResource enumeration.
    [HostProtectionAttribute(Resources=HostProtectionResource.All)]
    static int Main(string [] args)
    {
        try
        {
            // Show use of the HostProtectionResource.SharedState,
            // HostProtectionResource.SelfAffectingThreading, and
            // HostProtectionResource.Security enumeration values.
            ApplyIdentity();
            Directory.CreateDirectory("C:\\Temp");
            
            // Show use of the HostProtectionResource.Synchronization and
            // HostProtectionResource.ExternalThreading enumeration values.
            StartThread();
            Console.WriteLine("In the main thread.");
            Console.WriteLine("Deleting and creating 'MyTestFile.txt'.");
            if (File.Exists("C:\\Temp\\MyTestFile.txt"))
            {
                File.Delete("C:\\Temp\\MyTestFile.txt");
            }

            StreamWriter sr = File.CreateText("C:\\Temp\\MyTestFile.txt");
            sr.WriteLine ("This is my file.");
            sr.Close();
            Thread.Sleep(1000);
            
            // Show use of the HostProtectionResource.SharedState,
            // HostProtectionResource.SelfProcessMgmt,
            // HostProtectionResource.SelfAffectingThreading, and
            // HostProtectionResource.UI enumeration values.
            ExecuteBreak();
            
            // Show the use of the 
            // HostProtectionResource.ExternalProcessManagement 
            // enumeration value.
            MyControl myControl = new MyControl ();
            Console.WriteLine ("Enter 'q' to quit the sample.");
            return 100;
        }
        catch (Exception e)
        {
            Exit(e.ToString(), 0);
            return 0;
        }
    }

    // Define the event handlers.
    private static void OnChanged(object source, FileSystemEventArgs e)
    {
        // Specify whether a file is changed, created, or deleted.
        Console.WriteLine("In the OnChanged event handler.");
        Console.WriteLine("File: " + e.FullPath + " " + e.ChangeType);
    }
}

// The following class is an example of code that exposes 
// external process management.
// Add the LicenseProviderAttribute to the control.
[LicenseProvider (typeof(LicFileLicenseProvider))]
public class MyControl : System.Windows.Forms.Control
{
    // Create a new, null license.
    private License license = null;

    [HostProtection (ExternalProcessMgmt = true)]
    public MyControl ()
    {
        // Determine if a valid license can be granted.
        bool isValid = LicenseManager.IsValid (typeof(MyControl));
        Console.WriteLine ("The result of the IsValid method call is " + 
            isValid.ToString ());
    }

    protected override void Dispose (bool disposing)
    {
        if (disposing)
        {
            if (license != null)
            {
                license.Dispose ();
                license = null;
            }
        }
    }
}

Imports System.IO
Imports System.Threading
Imports System.Security
Imports System.Security.Policy
Imports System.Security.Principal
Imports System.Security.Permissions
Imports System.Diagnostics
Imports System.ComponentModel
Imports System.Windows.Forms


' If this application is run on a server that implements host protection, the
' HostProtectionAttribute attribute is applied. If the application is run on 
' a server that is not host-protected, the attribute evaporates; it is not  
' detected and therefore not applied. Host protection can be configured with  
' members of the HostProtectionResource enumeration to customize the  
' protection offered. 
' The primary intent of this sample is to show situations in which the 
' HostProtectionAttribute attribute might be meaningfully used.  The 
' environment required to demonstrate a particular behavior is too 
' complex to invoke within the scope of this sample.

Class HostProtectionExample
    Public Shared Success As Integer = 100

    ' Use the enumeration flags to indicate that this method exposes 
    ' shared state and self-affecting process management.
    ' Either of the following attribute statements can be used to set the 
    ' resource flags.
    <HostProtectionAttribute(SharedState := True, _
        SelfAffectingProcessMgmt := True), _
        HostProtectionAttribute( _
        Resources := HostProtectionResource.SharedState Or _
        HostProtectionResource.SelfAffectingProcessMgmt)> _
    Private Shared Sub [Exit](ByVal Message As String, ByVal Code As Integer)

        ' Exit the sample when an exception is thrown.
        Console.WriteLine((ControlChars.Lf & "FAILED: " & Message & " " & _
            Code.ToString()))
        Environment.ExitCode = Code
        Environment.Exit(Code)
    End Sub

    ' Use the enumeration flags to indicate that this method exposes shared
    ' state, self-affecting process management, and self-affecting threading.
    <HostProtectionAttribute(SharedState := True, _
        SelfAffectingProcessMgmt := True, _
        SelfAffectingThreading := True, UI := True)> _
    Private Shared Sub ExecuteBreak()

        ' This method allows the user to quit the sample.
        Console.WriteLine("Executing Debugger.Break.")
        Debugger.Break()
        Debugger.Log(1, "info", "test message")
    End Sub

    ' Use the enumeration flags to indicate that this method exposes shared  
    ' state, self-affecting threading, and the security infrastructure.
    <HostProtectionAttribute(SharedState := True, _
        SelfAffectingThreading := True, _
        SecurityInfrastructure := True)> _
    Private Shared Function ApplyIdentity() As Integer

        ' ApplyIdentity sets the current identity.
        Dim roles(1) As String
        Try
            Dim mAD As AppDomain = AppDomain.CurrentDomain
            Dim mGenPr As _
                New GenericPrincipal(WindowsIdentity.GetCurrent(), roles)
            mAD.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal)
            mAD.SetThreadPrincipal(mGenPr)
            Return Success
        Catch e As Exception
            [Exit](e.ToString(), 5)
        End Try
        Return 0
    End Function 'ApplyIdentity

    ' The following method is started on a separate thread.
    Public Shared Sub WatchFileEvents()
        Try
            Console.WriteLine("In the child thread.")
            Dim watcher As New FileSystemWatcher()
            watcher.Path = "C:\Temp"

            ' Watch for changes in LastAccess and LastWrite times, and 
            ' name changes to files or directories. 
            watcher.NotifyFilter = NotifyFilters.LastAccess Or _
                NotifyFilters.LastWrite Or NotifyFilters.FileName Or _
                NotifyFilters.DirectoryName

            ' Watch only text files.
            watcher.Filter = "*.txt"

            ' Add event handlers.
            AddHandler watcher.Changed, AddressOf OnChanged
            AddHandler watcher.Created, AddressOf OnChanged
            AddHandler watcher.Deleted, AddressOf OnChanged

            ' Begin watching.
            watcher.EnableRaisingEvents = True

            ' Wait for the user to quit the program.
            Console.WriteLine("Event handlers have been enabled.")
            While Console.ReadLine() <> "q"c
            End While
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub

    ' Use the enumeration flags to indicate that this method exposes  
    ' synchronization and external threading.
    <HostProtectionAttribute(Synchronization := True, _
        ExternalThreading := True)> _
    Private Shared Sub StartThread()
        Dim t As New Thread(New ThreadStart(AddressOf WatchFileEvents))

        ' Start the new thread. On a uniprocessor, the thread is not given 
        ' any processor time until the main thread yields the processor.  
        t.Start()

        ' Give the new thread a chance to execute.
        Thread.Sleep(1000)
    End Sub

    ' Call methods that show the use of the HostProtectionResource enumeration.
    <HostProtectionAttribute(Resources := HostProtectionResource.All)> _
    Overloads Shared Function Main(ByVal args() As String) As Integer
        Try
            ' Show use of the HostProtectionResource.SharedState,
            ' HostProtectionResource.SelfAffectingThreading, and
            ' HostProtectionResource.Security enumeration values.
            ApplyIdentity()
            Directory.CreateDirectory("C:\Temp")

            ' Show use of the HostProtectionResource.Synchronization and
            ' HostProtectionResource.ExternalThreading enumeration values.
            StartThread()
            Console.WriteLine("In the main thread.")
            Console.WriteLine("Deleting and creating 'MyTestFile.txt'.")
            If File.Exists("C:\Temp\MyTestFile.txt") Then
                File.Delete("C:\Temp\MyTestFile.txt")
            End If

            Dim sr As StreamWriter = File.CreateText("C:\Temp\MyTestFile.txt")
            sr.WriteLine("This is my file.")
            sr.Close()
            Thread.Sleep(1000)

            ' Show use of the HostProtectionResource.SharedState, 
            ' HostProtectionResource.SelfProcessMgmt,
            ' HostProtectionResource.SelfAffectingThreading, and
            ' HostProtectionResource.UI enumeration values.
            ExecuteBreak()

            ' Show the use of the 
            ' HostProtectionResource.ExternalProcessManagement 
            ' enumeration value.
            Dim myControl As New MyControl()
            Console.WriteLine("Enter 'q' to quit the sample.")
            Return 100
        Catch e As Exception
            [Exit](e.ToString(), 0)
            Return 0
        End Try
    End Function 'Main

    ' Define the event handlers.
    Private Shared Sub OnChanged(ByVal [source] As Object, _
        ByVal e As FileSystemEventArgs)

        ' Specify whether a file is changed, created, or deleted.
        Console.WriteLine("In the OnChanged event handler.")
        Console.WriteLine(("File: " & e.FullPath & " " & _
            e.ChangeType.ToString()))
    End Sub
End Class

' The following class is an example of code that exposes 
' external process management.
' Add the LicenseProviderAttribute to the control.
<LicenseProvider(GetType(LicFileLicenseProvider))> _
Public Class MyControl
    Inherits System.Windows.Forms.Control

    ' Create a new, null license.
    Private license As License = Nothing

    <HostProtectionAttribute(ExternalProcessMgmt := True)> _
    Public Sub New()

        ' Determine if a valid license can be granted.
        Dim isValid As Boolean = LicenseManager.IsValid(GetType(MyControl))
        Console.WriteLine(("The result of the IsValid method call is " & _
            isValid.ToString()))
    End Sub

    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (license Is Nothing) Then
                license.Dispose()
                license = Nothing
            End If
        End If
    End Sub
End Class

注解

此属性仅影响托管公共语言运行时和实现主机保护的非托管应用程序，例如SQL Server。 如果代码在客户端应用程序中运行或在非主机保护的服务器上运行，此特性则会“蒸发”；由于它不会被检测到，因此不会被应用。 应用后，安全性操作会导致基于类或方法公开的主机资源而创建链接要求。

如果此主机没有编程模型要求，则不会出现链接要求。

此特性可以标识以下各项：

• 不适合主机编程模型，但属于良性的方法或类。

• 不适合主机编程模型且可能导致破坏服务器托管的用户代码稳定性的方法或类。

• 不适合主机编程模型且可能导致破坏服务器进程自身稳定性的方法或类。

构造函数

属性

方法

显式接口实现

适用于

另请参阅

• 利用特性扩展元数据
• 链接需求