c# - 使用实例成员发布尖锐

Question

我正在尝试创建一个方面来管理类的一些属性的安全性。但是，一个成员的安全方面依赖于类的另一个属性中的数据。我已经阅读了一些关于 IntroduceAspect 的教程，但我不确定它是否是我需要的。

public class ClassWithThingsIWantToSecure
{

    [SecurityAspectHere(inherits from LocationInterceptionAspect)]
    public int ThingIWantToSecure;

    public string ThingINeedToKnowAboutInSecurityAspect;
}

有人可以指出正确的方向，使 ThingINeedToKnowAboutInSecurityAspect 的运行时值在 SecurityAspect 中可用吗？

Answer 1

我以前做过类似的事情，我在一台安装了 postsharp 的机器上进行了测试并试了一下，这是代码...

    class Program
{
    static void Main(string[] args)
    {
        Baldrick baldrick = new Baldrick();
        baldrick.ThingINeedToKnowAboutInSecurityAspect = "Bob";
        Console.WriteLine("There are {0} beans", baldrick.ThingIWantToSecure);

        baldrick.ThingINeedToKnowAboutInSecurityAspect = "Kate";

        try
        {
            //This should fail
            Console.WriteLine("There are {0} beans", baldrick.ThingIWantToSecure);
        }
        catch (Exception ex)
        {
            //Expect the message from my invalid operation exception to be written out (Use your own exception if you prefer)
            Console.WriteLine(ex.Message);
        }
        Console.ReadLine();
    }


}

[Serializable]
public class SecurityAspect : LocationInterceptionAspect
{
    public override void OnGetValue(LocationInterceptionArgs args)
    {
        ISecurityProvider securityProvider = args.Instance as ISecurityProvider;
        if (securityProvider != null && securityProvider.ThingINeedToKnowAboutInSecurityAspect != "Bob")
            throw new InvalidOperationException("Access denied (or a better message would be nice!)");
        base.OnGetValue(args);
    }
}



public interface ISecurityProvider
{
    string ThingINeedToKnowAboutInSecurityAspect { get; }
}

public class Baldrick : ISecurityProvider
{
    public string ThingINeedToKnowAboutInSecurityAspect { get; set; }

    [SecurityAspect]
    public int ThingIWantToSecure{get { return 3; }}
}

因此，这里的想法是查询正在装饰的对象的实例的 args.Instance 属性。