如何在WCF中使用自己的权限？

public class MyAuthorizationPolicy : IAuthorizationPolicy
{
    // 实现接口方法
}

PermissionSet permissionSet = new PermissionSet(PermissionState.None);
permissionSet.AddPermission(new MyAuthorizationPolicy());

ServiceHost serviceHost = new ServiceHost(typeof(MyService));
serviceHost.Authorization.AddPolicy(new MyAuthorizationPolicy());

ServiceAuthorizationBehavior serviceAuthorizationBehavior = new ServiceAuthorizationBehavior();
serviceAuthorizationBehavior.ExternalAuthorizationPolicies = new MyAuthorizationPolicy();

public class MyAuthorizationManager : ServiceAuthorizationManager
{
    // 重写CheckAccess方法
}

serviceHost.Authorization.ServiceAuthorizationManager = new MyAuthorizationManager();