HOW TO：執行命令式安全性檢查

對於命令式要求，您可以呼叫 PrincipalPermission 物件的 Demand 方法來判斷目前 Principal 物件是否代表指定的識別、角色或兩者。 假設正確建構的 PrincipalPermission 物件已呼叫 MyPrincipalPermission，則可以用下列程式碼來呼叫命令式要求。

MyPrincipalPermission.Demand()

MyPrincipalPermission.Demand();

範例

下列程式碼範例使用命令式檢查以確保 GenericPrincipal 符合 PrincipalPermission 物件。 當應用程式定義域中的許多方法或其他組件 (Assembly) 必須產生角色架構的判決時，命令式檢查很有用處。 雖然這個範例非常簡單，但是它卻可說明與角色架構要求關聯的行為。

Imports System
Imports System.Security.Permissions
Imports System.Security.Principal
Imports System.Security
Imports System.Threading
Imports System.Security.Cryptography

Public Class MainClass

    Public Overloads Shared Function Main() As Integer

        Console.WriteLine("Enter '1' to use the proper identity or " _
            & "any other character to use the improper identity.")

        If Console.ReadLine() = "1" Then
            ' Create a generic identity.
            Dim MyIdentity As New GenericIdentity("MyUser")

            ' Create a generic principal.
            Dim MyString As [String]() = {"Administrator", "User"}

            Dim MyPrincipal As New GenericPrincipal( _
                MyIdentity, MyString)

            Thread.CurrentPrincipal = MyPrincipal
        End If

        PrivateInfo()

        Return 0
    End Function

    Public Shared Sub PrivateInfo()
        Try
            ' Create a PrincipalPermission object.
            Dim MyPermission As New PrincipalPermission( _
                "MyUser", "Administrator")

            ' Demand this permission.
            MyPermission.Demand()

            ' Print secret data.
            Console.WriteLine(ControlChars.Cr & ControlChars.Cr & _
                "You have access to the private data!")
        Catch e As SecurityException
            Console.WriteLine(e.Message)
        End Try
    End Sub
End Class

using System;
using System.Security.Permissions;
using System.Security.Principal;
using System.Security;
using System.Threading;
using System.Security.Cryptography;

public class MainClass
{
    public static int Main(string[] args)
    {
        Console.WriteLine("Enter '1' to use the proper identity or " +
            "any other character to use the improper identity.");

        if(Console.ReadLine() == "1")
        {
            // Create a generic identity.
            GenericIdentity MyIdentity = new GenericIdentity("MyUser");

            // Create a generic principal.
            String[] MyString = {"Administrator", "User"};

            GenericPrincipal MyPrincipal = 
                new GenericPrincipal(MyIdentity, MyString);

            Thread.CurrentPrincipal = MyPrincipal;
        }

        PrivateInfo();
        return 0;
    }

    public static void PrivateInfo()
    {
        try
        {
            // Create a PrincipalPermission object.
            PrincipalPermission MyPermission = 
                new PrincipalPermission("MyUser", "Administrator");

            // Demand this permission.
            MyPermission.Demand();

            // Print secret data.
            Console.WriteLine(
                "\n\nYou have access to the private data!");
        }
        catch(SecurityException e) 
        {
            Console.WriteLine(e.Message);
        }
    }
}

如果使用者輸入 1，則建立存取 PrivateInfo 方法所需的 Principal 和 Identity 物件。 如果使用者輸入其他任何字元，則不會建立任何 Principal 和 Identity 物件，且會在呼叫 PrivateInfo 方法時擲回安全性例外狀況。 如果目前的執行緒與名為 MyUser 且角色為 Administrator 的當事人關聯，則會出現下列訊息。

You have access to the private data!

請參閱

參考

PrincipalPermission

概念

以角色為基礎的安全性檢查