工厂示例

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Configuration; using System.Reflection;  namespace Common.DALFactory {     /// <summary>     /// 数据层对象实例创建     /// </summary>     public partial class DbFactory     {         /// <summary>         /// 做缓存         /// </summary>         private static Dictionary<string, object> dic = new Dictionary<string, object>();          #region 程序集配置 -static readonly string DALAssembly         /// <summary>         /// 程序集配置         /// </summary>         private static readonly string DALAssembly = ConfigurationManager.AppSettings["dalAssembly"];          #endregion          #region 命名空间配置 -static readonly string DALNameSpace         /// <summary>         /// 命名空间配置         /// </summary>         private static readonly string DALNameSpace = ConfigurationManager.AppSettings["dalNameSpace"];          #endregion          #region 创建对象实例 -static object CreateInstance(string fullName, string assemblyName)         /// <summary>         /// 创建对象实例         /// </summary>         /// <param name="fullName">全名称 命名空间.类名</param>         /// <param name="assemblyName">程序集名称</param>         /// <returns></returns>         private static object CreateInstance(string fullName, string assemblyName)         {             string key = string.Format("{0}+{1}", assemblyName, fullName);             if (!dic.ContainsKey(key))             {                 Assembly assembly = Assembly.Load(assemblyName);    // 加载程序集                 object obj = assembly.CreateInstance(fullName);                 dic.Add(key, obj);             }             return dic[key];                     }          #endregion     } }