实例讲解设计模式之单件模式应用和简单注入实现形式(3)

/// <summary>
        /// 获取服务
        /// </summary>
        /// <param name="serviceType">服务类型</param>
        /// <param name="throwExceptionIfNotFound"></param>
        /// <returns></returns>
        public object GetService(Type serviceType)
        {
            if (ServiceTypes[serviceType.FullName] == null)
            {
                throw new Exception(serviceType.FullName + " 服务未找到！");
            }
            return ServiceTypes[serviceType.FullName];
        }

        /// <summary>
        /// 加载服务
        /// </summary>
        public void Load()
        {
            if (this.ServiceTypes.Count > 0)
            {
                this.ServiceTypes.Clear();
            }
            lock (typeof(ServiceManager))
            {
                this.AllServiceAdd();
            }
        }

        /// <summary>
        /// 所有服务加载
        /// </summary>
        private void AllServiceAdd()
        {
            XmlDocument document = new XmlDocument();
            Type type = null;
            Type serviceType = null;
            // boot.config启动文件
            document.Load(@"D:\RayGu\Visual Studio 2008\WebSites\WebSite3\boot.config");
            XmlElement documentElement = document.DocumentElement;
            if (!((documentElement != null) && string.Equals(documentElement.Name, "Boot")))
            {
                throw new Exception(" boot.config服务配置失败!");
            }
            foreach (XmlNode node in documentElement.SelectNodes("/Boot/Services/Service"))
            {
                if (node.NodeType == XmlNodeType.Element)
                {
                    XmlElement element2 = (XmlElement)node;
                    // 驱动
                    string attribute = element2.GetAttribute("Driver");
                    // 服务类型
                    string typeFullName = element2.GetAttribute("Type");
                    if (attribute == null)
                    {
                        throw new Exception(serviceType.FullName + " 服务驱动加载失败!");
                    }
                    type = ServiceManager.GetType(attribute);
                    serviceType = ServiceManager.GetType(typeFullName);
                    if (((type != null) && (serviceType != null)))
                    {
                        this.AcquireObject(type, serviceType.FullName);
                    }
                    else
                    {
                        throw new Exception(serviceType.FullName + " 服务加载失败!");
                    }
                }
            }
        }

        public object AcquireObject(Type type, string serviceTypeFullname)
        {
            if (this.ServiceTypes.Contains(serviceTypeFullname))
            {
                return this.ServiceTypes[serviceTypeFullname];
            }
            lock (this.ServiceTypes.SyncRoot)
            {
                this.ServiceTypes.Add(serviceTypeFullname, Activator.CreateInstance(type));
                return this.ServiceTypes[serviceTypeFullname];
            }
        }

        public static Type GetType(string typeFullName)
        {
            Type type = Type.GetType(typeFullName);
            if (type != null)
            {
                return type;
            }
            string name = typeFullName.Substring(0, typeFullName.IndexOf(","));
            string str2 = typeFullName.Substring(typeFullName.IndexOf(",") + 1);
            string assemblyName = (str2.IndexOf(",") >= 0) ? str2.Substring(0, str2.IndexOf(",")) : str2;
            name = name.Trim();
            assemblyName = assemblyName.Trim();
            if ((assemblyName != null) && (name != null))
            {
                Assembly assemblyByPartialName = GetAssemblyByPartialName(assemblyName);
                if (assemblyByPartialName != null)
                {
                    return assemblyByPartialName.GetType(name);
                }
            }
            return null;
        }

        public static Assembly GetAssemblyByPartialName(string assemblyName)
        {
            string str = assemblyName + ",";
            Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
            foreach (Assembly assembly in assemblies)
            {
                if (assembly.FullName.ToLower().StartsWith(str.ToLower()))
                {
                    return assembly;
                }
            }
            return null;
        }

通过配置加载

<?xml version="1.0" encoding="utf-8" ?>
<Boot>
  <Services>
    <Service Type="IService.IUserService, IService" Driver="Service.UserService, Service" />
  </Services>
</Boot>

页面实现过程

public static IUserService UserService
    {
        get
        {
            return (IUserService)ServiceManager.Instance.GetService(typeof(IUserService));
        }
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Users users = UserService.Load();
            string output = "";
            output += "<table><tr><th>编号</th><th>用户名</th><th>密码</th></tr>";
            foreach (User user in users)
            {
                output += "<tr><td>" + user.Id + "</td><td>" + user.Name + "</td><td>" + user.Password + "</td></tr>";
            }
            output += "</table>";

            this.PlaceHolder1.Controls.Add(new LiteralControl(output));
        }
    }