AllowPartiallyTrustedCallersAttribute Classe

Definição

Permite que um assembly seja chamado por código parcialmente confiável.Allows an assembly to be called by partially trusted code. Sem esta declaração, somente os chamadores totalmente confiáveis podem usar o assembly.Without this declaration, only fully trusted callers are able to use the assembly. Essa classe não pode ser herdada.This class cannot be inherited.

public ref class AllowPartiallyTrustedCallersAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Assembly, AllowMultiple=false, Inherited=false)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class AllowPartiallyTrustedCallersAttribute : Attribute
type AllowPartiallyTrustedCallersAttribute = class
    inherit Attribute
Public NotInheritable Class AllowPartiallyTrustedCallersAttribute
Inherits Attribute
Herança
AllowPartiallyTrustedCallersAttribute
Atributos

Exemplos

O exemplo a seguir mostra como usar a classe AllowPartiallyTrustedCallersAttribute.The following example shows how to use the AllowPartiallyTrustedCallersAttribute class.

// The following HTML code can be used to call the user control in this sample.
//
//  <OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800"
//  height="300" style="font-size:12;">
// To run this test control you must create a strong name key, snkey.snk, and
// a code group that gives full trust to assemblies signed with snkey.snk.
// The user control displays an OpenFileDialog box, then displays a text box containing the name of
// the file selected and a list box that displays the contents of the file.  The selected file must
// contain text in order for the control to display the data properly.
// Caution  This sample demonstrates the use of the Assert method.  Calling Assert removes the
// requirement that all code in the call chain must be granted permission to access the specified
// resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore,
// it should be used with great caution.  Assert should always be followed with a RevertAssert
// command to restore the security settings.
#using <System.Windows.Forms.dll>
#using <System.Data.dll>
#using <System.Drawing.dll>
#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::ComponentModel;
using namespace System::Drawing;
using namespace System::Data;
using namespace System::Windows::Forms;
using namespace System::IO;
using namespace System::Security;
using namespace System::Security::Permissions;
using namespace System::Reflection;
using namespace System::Runtime::CompilerServices;

// This strong name key is used to create a code group that gives permissions to this assembly.
// The AllowPartiallyTrustedCallersAttribute requires the assembly to be signed with a strong name key.
// This attribute is necessary since the control is called by either an intranet or Internet
// Web page that should be running under restricted permissions.
// The userControl1 displays an OpenFileDialog box, then displays a text box containing the name of 
// the file selected and a list box that displays the contents of the file.  The selected file must 
// contain text in order for the control to display the data properly.

[assembly:AssemblyKeyFile("snKey.snk")];
[assembly:AssemblyVersion("1.0.0.0")];
[assembly:AllowPartiallyTrustedCallers];
public ref class UserControl1: public System::Windows::Forms::UserControl
{
private:
   System::Windows::Forms::TextBox^ textBox1;
   System::Windows::Forms::ListBox^ listBox1;

   // Required designer variable.
   System::ComponentModel::Container^ components;

public:
// Demand the zone requirement for the calling application.
[ZoneIdentityPermission(SecurityAction::Demand, Zone = SecurityZone::Intranet)]
   UserControl1()
   {
      
      // This call is required by the Windows.Forms Form Designer.
      InitializeComponent();
      
      // The OpenFileDialog box should not require any special permissions.
      OpenFileDialog^ fileDialog = gcnew OpenFileDialog;
      if ( fileDialog->ShowDialog() == DialogResult::OK )
      {
         
         // Reading the name of the selected file from the OpenFileDialog box
         // and reading the file requires FileIOPermission.  The user control should 
         // have this permission granted through its code group; the Web page that calls the 
         // control should not have this permission.  The Assert command prevents a stack walk 
         // that would fail because the caller does not have the required FileIOPermission.  
         // The use of Assert can open up security vulnerabilities if used incorrectly or 
         // inappropriately. Therefore, it should be used with great caution.
         // The Assert command should be followed by a RevertAssert as soon as the file operation 
         // is completed.
         (gcnew FileIOPermission( PermissionState::Unrestricted ))->Assert();
         textBox1->Text = fileDialog->FileName;

         // Display the contents of the file in the text box.
         FileStream^ fsIn = gcnew FileStream( textBox1->Text,FileMode::Open,FileAccess::Read,FileShare::Read );
         StreamReader^ sr = gcnew StreamReader( fsIn );
         
         // Process every line in the file
         for ( String ^ Line = sr->ReadLine(); Line != nullptr; Line = sr->ReadLine() )
         {
            listBox1->Items->Add( Line );

         }

         // file operations.
         FileIOPermission::RevertAssert();
      }
   }

private:

   /// <summary>
   /// Required method for Designer support - do not modify 
   /// the contents of this method with the code editor.
   /// </summary>
   void InitializeComponent()
   {
      this->textBox1 = gcnew System::Windows::Forms::TextBox;
      this->listBox1 = gcnew System::Windows::Forms::ListBox;
      this->SuspendLayout();
      
      // 
      // textBox1
      // 
      this->textBox1->Location = System::Drawing::Point( 208, 112 );
      this->textBox1->Name = "textBox1";
      this->textBox1->Size = System::Drawing::Size( 320, 20 );
      this->textBox1->TabIndex = 0;
      this->textBox1->Text = "textBox1";
      this->textBox1->TextChanged += gcnew System::EventHandler( this,&UserControl1::textBox1_TextChanged );
      
      // 
      // listBox1
      // 
      this->listBox1->Location = System::Drawing::Point( 200, 184 );
      this->listBox1->Name = "listBox1";
      this->listBox1->Size = System::Drawing::Size( 336, 108 );
      this->listBox1->TabIndex = 1;
      
      // 
      // UserControl1
      // 
      this->Controls->Add( this->listBox1 );
      this->Controls->Add( this->textBox1 );
      this->Name = "UserControl1";
      this->Size = System::Drawing::Size( 592, 400 );
      this->Load += gcnew System::EventHandler( this,&UserControl1::UserControl1_Load );
      this->ResumeLayout( false );
   }

   void UserControl1_Load( Object^ /*sender*/, System::EventArgs^ /*e*/ ){}

   void textBox1_TextChanged( Object^ /*sender*/, System::EventArgs^ /*e*/ ){}

};

// The following HTML code can be used to call the user control in this sample.
//
//		<OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800"
//		height="300" style="font-size:12;">

// To run this test control you must create a strong name key, snkey.snk, and 
// a code group that gives full trust to assemblies signed with snkey.snk.

// The user control displays an OpenFileDialog box, then displays a text box containing the name of 
// the file selected and a list box that displays the contents of the file.  The selected file must 
// contain text in order for the control to display the data properly.

// Caution  This sample demonstrates the use of the Assert method.  Calling Assert removes the 
// requirement that all code in the call chain must be granted permission to access the specified 
// resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore, 
// it should be used with great caution.  Assert should always be followed with a RevertAssert 
// command to restore the security settings.


using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.IO;
using System.Security;
using System.Security.Permissions;
using System.Reflection;
using System.Runtime.CompilerServices;

// This strong name key is used to create a code group that gives permissions to this assembly.
[assembly: AssemblyKeyFile("snKey.snk")]
[assembly: AssemblyVersion("1.0.0.0")]

// The AllowPartiallyTrustedCallersAttribute requires the assembly to be signed with a strong name key.
// This attribute is necessary since the control is called by either an intranet or Internet
// Web page that should be running under restricted permissions.
[assembly:AllowPartiallyTrustedCallers]
namespace UserControl
{
    // The userControl1 displays an OpenFileDialog box, then displays a text box containing the name of 
    // the file selected and a list box that displays the contents of the file.  The selected file must 
    // contain text in order for the control to display the data properly.
    public class UserControl1 : System.Windows.Forms.UserControl
    {
        private System.Windows.Forms.TextBox textBox1;
        private System.Windows.Forms.ListBox listBox1;
        // Required designer variable.
        private System.ComponentModel.Container components = null;

              // Demand the zone requirement for the calling application.
              [ZoneIdentityPermission(SecurityAction.Demand, Zone = SecurityZone.Intranet)]
        public UserControl1()
        {
            // This call is required by the Windows.Forms Form Designer.
            InitializeComponent();

            // The OpenFileDialog box should not require any special permissions.
            OpenFileDialog fileDialog = new OpenFileDialog();
            if(fileDialog.ShowDialog() == DialogResult.OK)
            {
                // Reading the name of the selected file from the OpenFileDialog box
                // and reading the file requires FileIOPermission.  The user control should 
                // have this permission granted through its code group; the Web page that calls the 
                // control should not have this permission.  The Assert command prevents a stack walk 
                // that would fail because the caller does not have the required FileIOPermission.  
                // The use of Assert can open up security vulnerabilities if used incorrectly or 
                // inappropriately. Therefore, it should be used with great caution.
                // The Assert command should be followed by a RevertAssert as soon as the file operation 
                // is completed.
                new FileIOPermission(PermissionState.Unrestricted).Assert();
                textBox1.Text = fileDialog.FileName;
                // Display the contents of the file in the text box.
                FileStream fsIn = new FileStream(textBox1.Text, FileMode.Open, FileAccess.Read, 
                    FileShare.Read);
                StreamReader sr = new StreamReader(fsIn);
            
                // Process every line in the file
                for (String Line = sr.ReadLine(); Line != null; Line = sr.ReadLine()) 
                {
                    listBox1.Items.Add(Line);
                }
                // It is very important to call RevertAssert to restore the stack walk for
                // file operations.
                FileIOPermission.RevertAssert();
            }

        }

        // Clean up any resources being used.
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if( components != null )
                    components.Dispose();
            }
            base.Dispose( disposing );
        }

        #region Component Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify 
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.listBox1 = new System.Windows.Forms.ListBox();
            this.SuspendLayout();
            // 
            // textBox1
            // 
            this.textBox1.Location = new System.Drawing.Point(208, 112);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(320, 20);
            this.textBox1.TabIndex = 0;
            this.textBox1.Text = "textBox1";
            this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
            // 
            // listBox1
            // 
            this.listBox1.Location = new System.Drawing.Point(200, 184);
            this.listBox1.Name = "listBox1";
            this.listBox1.Size = new System.Drawing.Size(336, 108);
            this.listBox1.TabIndex = 1;
            // 
            // UserControl1
            // 
            this.Controls.Add(this.listBox1);
            this.Controls.Add(this.textBox1);
            this.Name = "UserControl1";
            this.Size = new System.Drawing.Size(592, 400);
            this.Load += new System.EventHandler(this.UserControl1_Load);
            this.ResumeLayout(false);

        }
        #endregion

        private void UserControl1_Load(object sender, System.EventArgs e)
        {
        
        }

        private void textBox1_TextChanged(object sender, System.EventArgs e)
        {
        
        }


    }
}
' The following HTML code can be used to call the user control in this sample.
'
'		<OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800"
'		height="300" style="font-size:12;">
' To run this test control you must create a strong name key, snkey.snk, and 
' a code group that gives full trust to assemblies signed with snkey.snk.
' The user control displays an OpenFileDialog box, then displays a text box containing the name of 
' the file selected and a list box that displays the contents of the file.  The selected file must 
' contain text in order for the control to display the data properly.
' Caution  This sample demonstrates the use of the Assert method.  Calling Assert removes the 
' requirement that all code in the call chain must be granted permission to access the specified 
' resource, it can open up security vulnerabilities if used incorrectly or inappropriately. Therefore, 
' it should be used with great caution.  Assert should always be followed with a RevertAssert 
' command to restore the security settings.

Imports System.Collections
Imports System.ComponentModel
Imports System.Drawing
Imports System.Data
Imports System.Windows.Forms
Imports System.IO
Imports System.Security
Imports System.Security.Permissions
Imports System.Reflection
Imports System.Runtime.CompilerServices

' This strong name key is used to create a code group that gives permissions to this assembly.

<Assembly: AssemblyKeyFile("snKey.snk")> 

<Assembly: AssemblyVersion("1.0.0.0")> 
' The AllowPartiallyTrustedCallersAttribute requires the assembly to be signed with a strong name key.
' This attribute is necessary since the control is called by either an intranet or Internet
' Web page that should be running under restricted permissions.

<Assembly: AllowPartiallyTrustedCallers()> 

' The userControl1 displays an OpenFileDialog box, then displays a text box containing the name of 
' the file selected and a list box that displays the contents of the file.  The selected file must 
' contain text in order for the control to display the data properly.

'Demand the zone requirement for the calling application.
<ZoneIdentityPermissionAttribute(SecurityAction.Demand, Zone:=SecurityZone.Intranet)> _
Public Class UserControl1
    Inherits System.Windows.Forms.UserControl
    Private WithEvents textBox1 As System.Windows.Forms.TextBox
    Private listBox1 As System.Windows.Forms.ListBox
    ' Required designer variable.
    Private components As System.ComponentModel.Container = Nothing


    Public Sub New()
        ' This call is required by the Windows.Forms Form Designer.
        InitializeComponent()

        ' The OpenFileDialog box should not require any special permissions.
        Dim fileDialog As New OpenFileDialog
        If fileDialog.ShowDialog() = DialogResult.OK Then
            ' Reading the name of the selected file from the OpenFileDialog box
            ' and reading the file requires FileIOPermission.  The user control should 
            ' have this permission granted through its code group; the Web page that calls the 
            ' control should not have this permission.  The Assert command prevents a stack walk 
            ' that would fail because the caller does not have the required FileIOPermission.  
            ' The use of Assert can open up security vulnerabilities if used incorrectly or 
            ' inappropriately. Therefore, it should be used with great caution.
            ' The Assert command should be followed by a RevertAssert as soon as the file operation 
            ' is completed.
            Dim fileIOPermission As New FileIOPermission(PermissionState.Unrestricted)
            fileIOPermission.Assert()
            textBox1.Text = fileDialog.FileName
            ' Display the contents of the file in the text box.
            Dim fsIn As New FileStream(textBox1.Text, FileMode.Open, FileAccess.Read, FileShare.Read)
            Dim sr As New StreamReader(fsIn)

            ' Process every line in the file
            Dim Line As String
            Line = sr.ReadLine()
            While Not (Line Is Nothing)
                listBox1.Items.Add(Line)
                Line = sr.ReadLine()
            End While
            ' It is very important to call RevertAssert to restore the stack walk for
            ' file operations.
            fileIOPermission.RevertAssert()
        End If
    End Sub


    ' Clean up any resources being used.
    Protected Overloads Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub


    ' Required method for Designer support - do not modify 
    ' the contents of this method with the code editor.
    Private Sub InitializeComponent()
        Me.textBox1 = New System.Windows.Forms.TextBox
        Me.listBox1 = New System.Windows.Forms.ListBox
        Me.SuspendLayout()
        ' 
        ' textBox1
        ' 
        Me.textBox1.Location = New System.Drawing.Point(208, 112)
        Me.textBox1.Name = "textBox1"
        Me.textBox1.Size = New System.Drawing.Size(320, 20)
        Me.textBox1.TabIndex = 0
        Me.textBox1.Text = "textBox1"
        ' 
        ' listBox1
        ' 
        Me.listBox1.Location = New System.Drawing.Point(200, 184)
        Me.listBox1.Name = "listBox1"
        Me.listBox1.Size = New System.Drawing.Size(336, 108)
        Me.listBox1.TabIndex = 1
        ' 
        ' UserControl1
        ' 
        Me.Controls.Add(listBox1)
        Me.Controls.Add(textBox1)
        Me.Name = "UserControl1"
        Me.Size = New System.Drawing.Size(592, 400)
        Me.ResumeLayout(False)
    End Sub

    Private Sub UserControl1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
    End Sub

    Private Sub textBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles textBox1.TextChanged
    End Sub
End Class

Comentários

Importante

Não há mais suporte para código parcialmente confiável.Partially trusted code is no longer supported. Esse atributo não tem nenhum efeito no .NET Core.This attribute has no effect in .NET Core.

Observação

O .NET Framework 4.NET Framework 4 introduz novas regras de segurança que afetam o comportamento do atributo AllowPartiallyTrustedCallersAttribute (consulte código de segurança transparente, nível 2).The .NET Framework 4.NET Framework 4 introduces new security rules that affect the behavior of the AllowPartiallyTrustedCallersAttribute attribute (see Security-Transparent Code, Level 2). No .NET Framework 4.NET Framework 4, todos os códigos assumem a segurança transparente, ou seja, parcialmente confiável.In the .NET Framework 4.NET Framework 4, all code defaults to security-transparent, that is, partially trusted. No entanto, você pode anotar tipos individuais e membros para atribuí-los a outros atributos de transparência.However, you can annotate individual types and members to assign them other transparency attributes. Para essa e outras alterações de segurança, consulte alterações de segurança.For this and other security changes, see Security Changes.

.NET Framework os assemblies da versão 2,0 () devem ter nomes fortes para usar efetivamente o atributo AllowPartiallyTrustedCallersAttribute (APTCA)..NET Framework version 2.0 () assemblies must be strong-named to effectively use the AllowPartiallyTrustedCallersAttribute (APTCA) attribute. os assemblies .NET Framework 4.NET Framework 4 () não precisam ter um nome forte para que o atributo APTCA seja eficaz e podem conter código transparente, de segurança crítica e com segurança crítica..NET Framework 4.NET Framework 4 () assemblies do not have to be strong-named for the APTCA attribute to be effective, and they can contain transparent, security-critical and security-safe-critical code. Para obter mais informações sobre como aplicar atributos no nível do assembly, consulte aplicando atributos.For more information about applying attributes at the assembly level, see Applying Attributes.

Por padrão, se um assembly de nome forte não aplicar explicitamente esse atributo no nível de assembly, ele só poderá ser chamado por outros assemblies que recebem confiança total.By default, if a strong-named, assembly does not explicitly apply this attribute at the assembly level, it can be called only by other assemblies that are granted full trust. Essa restrição é imposta colocando-se um LinkDemand para FullTrust em cada método público ou protegido em cada classe publicamente acessível no assembly.This restriction is enforced by placing a LinkDemand for FullTrust on every public or protected method on every publicly accessible class in the assembly. Os assemblies que se destinam a serem chamados pelo código parcialmente confiável podem declarar sua intenção por meio do uso de AllowPartiallyTrustedCallersAttribute.Assemblies that are intended to be called by partially trusted code can declare their intent through the use of AllowPartiallyTrustedCallersAttribute. Um exemplo da declaração no C# é [assembly:AllowPartiallyTrustedCallers]; um exemplo em Visual Basic é <assembly:AllowPartiallyTrustedCallers>.An example of the declaration in C# is [assembly:AllowPartiallyTrustedCallers]; an example in Visual Basic is <assembly:AllowPartiallyTrustedCallers>.

Cuidado

A presença desse atributo no nível do assembly impede o comportamento padrão de colocar FullTrust @ no__t-1 verificações de segurança e torna o assembly que possa ser chamado de qualquer outro assembly (parcialmente ou totalmente confiável).The presence of this assembly-level attribute prevents the default behavior of placing FullTrustLinkDemand security checks, and makes the assembly callable from any other (partially or fully trusted) assembly.

Quando o atributo APTCA está presente, todas as outras verificações de segurança funcionam conforme o esperado, incluindo quaisquer atributos de segurança declarativos no nível de classe ou de método que estejam presentes.When the APTCA attribute is present, all other security checks function as intended, including any class-level or method-level declarative security attributes that are present. Esse atributo bloqueia apenas a demanda de chamador implícita e totalmente confiável.This attribute blocks only the implicit, fully trusted caller demand.

Esse não é um atributo de segurança declarativo, mas um atributo regular (deriva de System.Attribute, não de System.Security.Permissions.SecurityAttribute).This is not a declarative security attribute, but a regular attribute (it derives from System.Attribute, not from System.Security.Permissions.SecurityAttribute).

Para obter mais informações, consulte usando bibliotecas de código parcialmente confiável.For more information, see Using Libraries from Partially Trusted Code.

Construtores

AllowPartiallyTrustedCallersAttribute()

Inicializa uma nova instância da classe AllowPartiallyTrustedCallersAttribute.Initializes a new instance of the AllowPartiallyTrustedCallersAttribute class.

Propriedades

PartialTrustVisibilityLevel

Obtém ou define a visibilidade de confiança parcial padrão para o código que é marcado com o atributo AllowPartiallyTrustedCallersAttribute (APTCA).Gets or sets the default partial trust visibility for code that is marked with the AllowPartiallyTrustedCallersAttribute (APTCA) attribute.

TypeId

Quando implementado em uma classe derivada, obtém um identificador exclusivo para este Attribute.When implemented in a derived class, gets a unique identifier for this Attribute.

(Herdado de Attribute)

Métodos

Equals(Object)

Retorna um valor que indica se essa instância é igual a um objeto especificado.Returns a value that indicates whether this instance is equal to a specified object.

(Herdado de Attribute)
GetHashCode()

Retorna o código hash para essa instância.Returns the hash code for this instance.

(Herdado de Attribute)
GetType()

Obtém o Type da instância atual.Gets the Type of the current instance.

(Herdado de Object)
IsDefaultAttribute()

Quando substituído em uma classe derivada, indica se o valor dessa instância é o valor padrão para a classe derivada.When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(Herdado de Attribute)
Match(Object)

Quando substituído em uma classe derivada, retorna um valor que indica se essa instância é igual a um objeto especificado.When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(Herdado de Attribute)
MemberwiseClone()

Cria uma cópia superficial do Object atual.Creates a shallow copy of the current Object.

(Herdado de Object)
ToString()

Retorna uma cadeia de caracteres que representa o objeto atual.Returns a string that represents the current object.

(Herdado de Object)

Implantações explícitas de interface

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

Mapeia um conjunto de nomes para um conjunto correspondente de identificadores de expedição.Maps a set of names to a corresponding set of dispatch identifiers.

(Herdado de Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Recupera as informações de tipo para um objeto, que pode ser usado para obter as informações de tipo para uma interface.Retrieves the type information for an object, which can be used to get the type information for an interface.

(Herdado de Attribute)
_Attribute.GetTypeInfoCount(UInt32)

Retorna o número de interfaces de informações do tipo que um objeto fornece (0 ou 1).Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(Herdado de Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Fornece acesso a propriedades e métodos expostos por um objeto.Provides access to properties and methods exposed by an object.

(Herdado de Attribute)

Aplica-se a