Consente a un assembly di essere chiamato da codice parzialmente attendibile. Senza questa dichiarazione, solo i chiamanti completamente attendibili possono utilizzare l'assembly. La classe non può essere ereditata.
System.Attribute
System.Security.AllowPartiallyTrustedCallersAttribute
Spazio dei nomi: System.Security
Assembly: mscorlib (in mscorlib.dll)
<AttributeUsageAttribute(AttributeTargets.Assembly, AllowMultiple := False, _ Inherited := False)> _ <ComVisibleAttribute(True)> _ Public NotInheritable Class AllowPartiallyTrustedCallersAttribute _ Inherits Attribute
[AttributeUsageAttribute(AttributeTargets.Assembly, AllowMultiple = false, Inherited = false)] [ComVisibleAttribute(true)] public sealed class AllowPartiallyTrustedCallersAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Assembly, AllowMultiple = false, Inherited = false)] [ComVisibleAttribute(true)] public ref class AllowPartiallyTrustedCallersAttribute sealed : public Attribute
[<Sealed>] [<AttributeUsageAttribute(AttributeTargets.Assembly, AllowMultiple = false, Inherited = false)>] [<ComVisibleAttribute(true)>] type AllowPartiallyTrustedCallersAttribute = class inherit Attribute end
Il tipo AllowPartiallyTrustedCallersAttribute espone i seguenti membri.
| Nome | Descrizione | |
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AllowPartiallyTrustedCallersAttribute | Inizializza una nuova istanza della classe AllowPartiallyTrustedCallersAttribute. |
| Nome | Descrizione | |
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PartialTrustVisibilityLevel | Ottiene o imposta la visibilità predefinita in un contesto parzialmente attendibile del codice contrassegnato con l'attributo AllowPartiallyTrustedCallersAttribute (APTCA). |
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TypeId | Quando è implementata in una classe derivata, ottiene un identificatore univoco della classe Attribute. (Ereditato da Attribute) |
| Nome | Descrizione | |
|---|---|---|
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Equals | Infrastruttura. Restituisce un valore che indica se l'istanza è uguale a un oggetto specificato. (Ereditato da Attribute) |
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Finalize | Consente a un oggetto di provare a liberare risorse ed eseguire altre operazioni di pulitura prima che l'oggetto stesso venga recuperato dalla procedura di Garbage Collection. (Ereditato da Object) |
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GetHashCode | Restituisce il codice hash per l'istanza. (Ereditato da Attribute) |
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GetType | Ottiene l'oggetto Type dell'istanza corrente. (Ereditato da Object) |
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IsDefaultAttribute | Quando è sottoposto a override in una classe derivata, indica se il valore di questa istanza è il valore predefinito della classe derivata. (Ereditato da Attribute) |
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Match | Quando è sottoposto a override in una classe derivata, restituisce un valore che indica se questa istanza equivale a un oggetto specificato. (Ereditato da Attribute) |
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MemberwiseClone | Consente di creare una copia dei riferimenti dell'oggetto Object corrente. (Ereditato da Object) |
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ToString | Restituisce una stringa che rappresenta l'oggetto corrente. (Ereditato da Object) |
| Nome | Descrizione | |
|---|---|---|
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_Attribute.GetIDsOfNames | Esegue il mapping di un set di nomi a un set corrispondente di ID di invio. (Ereditato da Attribute) |
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_Attribute.GetTypeInfo | Recupera le informazioni sul tipo relative a un oggetto, che possono essere utilizzate per ottenere informazioni sul tipo relative a un'interfaccia. (Ereditato da Attribute) |
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_Attribute.GetTypeInfoCount | Recupera il numero delle interfacce di informazioni di tipo fornite da un oggetto (0 o 1). (Ereditato da Attribute) |
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_Attribute.Invoke | Fornisce l'accesso a proprietà e metodi esposti da un oggetto. (Ereditato da Attribute) |
Nota
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.NET Framework versione 4introduce le nuove regole di sicurezza che influiscono sul comportamento dell'attributo AllowPartiallyTrustedCallersAttribute (vedere Codice SecurityTransparent, livello 2). In .NET Framework 4, ogni codice imposta come valore predefinito SecurityTransparent, ovvero, parzialmente attendibile. Tuttavia, è possibile annotare tipi e membri singoli per assegnargli altri attributi di trasparenza. Per questa e altre modifiche di sicurezza, vedere Modifiche della sicurezza in .NET Framework 4 (la pagina potrebbe essere in inglese). |
In .NET Framework versione 2.0 gli assembly (trasparenza di livello 1) devono possedere un nome sicuro per utilizzare efficacemente l'attributo AllowPartiallyTrustedCallersAttribute (APTCA). Gli assembly .NET Framework 4 (livello 2) non devono avere un nome sicuro per l'attributo APTCA per essere efficaci e possono contenere un codice trasparente, SecurityCritical e SecuritySafeCritical. Per ulteriori informazioni sull'applicazione di attributi a livello di assembly, vedere Applicazione di attributi.
Per impostazione predefinita, se un assembly con nome sicuro trasparenza di livello 1 non applica in modo esplicito questo attributo a livello di assembly, potrà essere chiamato solo da altri assembly a cui è stata concessa l'attendibilità completa. Questa restrizione viene applicata inserendo una richiesta LinkDemand per FullTrust in ogni metodo pubblico o protetto di ogni classe dell'assembly a cui è possibile accedere pubblicamente. Gli assembly che devono essere chiamati da codice parzialmente attendibile possono dichiarare il proprio scopo tramite l'utilizzo di AllowPartiallyTrustedCallersAttribute. Un esempio di tale dichiarazione in C# è [assembly:AllowPartiallyTrustedCallers], mentre in Visual Basic è <assembly:AllowPartiallyTrustedCallers> .
Attenzione
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La presenza dell'attributo a livello di assembly impedisce il comportamento predefinito di inserimento di controlli di sicurezza FullTrustLinkDemand e consente di chiamare l'assembly da qualsiasi altro assembly, parzialmente o completamente attendibile. |
Quando l'attributo APTCA è presente, tutti gli altri controlli di sicurezza funzioneranno nel modo previsto, inclusi eventuali attributi dichiarativi a livello di classe o di metodo. Questo attributo blocca solo la richiesta del chiamante implicito, completamente attendibile.
Non si tratta di un attributo di sicurezza dichiarativo, ma di un attributo regolare, derivante da System.Attribute e non da System.Security.Permissions.SecurityAttribute.
Per ulteriori informazioni, vedere Utilizzo di librerie da codice parzialmente attendibile.
Nell'esempio seguente viene illustrato come utilizzare la classe AllowPartiallyTrustedCallersAttribute.
' The following HTML code can be used to call the user control in this sample. ' '<HTML> ' <BODY> ' <OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800" ' height="300" style="font-size:12;"> ' </OBJECT> ' <p> ' </BODY> '</HTML> ' 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 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 Imports Microsoft.VisualBasic ' 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 'New ' 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 'Dispose ' 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 'InitializeComponent Private Sub UserControl1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load End Sub 'UserControl1_Load Private Sub textBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles textBox1.TextChanged End Sub 'textBox1_TextChanged End Class 'UserControl1
// The following HTML code can be used to call the user control in this sample. // //<HTML> // <BODY> // <OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800" // height="300" style="font-size:12;"> // </OBJECT> // <p> // </BODY> //</HTML> // 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. // //<HTML> // <BODY> // <OBJECT id="usercontrol" classid="usercontrol.dll#UserControl.UserControl1" width="800" // height="300" style="font-size:12;"> // </OBJECT> // <p> // </BODY> //</HTML> // 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*/ ){} };
.NET Framework
Supportato in: 4, 3.5, 3.0, 2.0, 1.1, 1.0.NET Framework Client Profile
Supportato in: 4, 3.5 SP1Windows 7, Windows Vista SP1 o versione successiva, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (componenti di base del server non supportati), Windows Server 2008 R2 (componenti di base del server supportati con SP1 o versione successiva), Windows Server 2003 SP2
.NET Framework non supporta tutte le versioni di ciascuna piattaforma. Per un elenco delle versioni supportate, vedere Requisiti di sistema di .NET Framework.
Nota
Attenzione