HOW TO：執行命令式安全性檢查

更新：2007 年 11 月

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

概念

以角色為基礎的安全性檢查

參考

PrincipalPermission