Csharp:use Activator.CreateInstance with an Interface?
///<summary> ///数据访问工厂 ///生成時間2015-2-13 10:54:34 ///塗聚文(Geovin Du) /// (利用工厂模式+反射机制+缓存机制,实现动态创建不同的数据层对象接口) ///</summary> public class AbstractFactory { protected static string path = ConfigurationManager.AppSettings["WebDAL"]; //"DAL";//生成的DLL文件名 /// <summary> /// 数据库类型 /// </summary> protected static string dalType { get { if (path.Contains("AccessDAL")) { //path = "AcessDAL"; return "AccessDAL"; } else if (path=="DAL") { // path = "DAL";//生成的DLL文件名 return "SqlServerDAL";//命名空间名称 } else if (path.Contains("MySQLDAL")) { return "MySQLDAL"; } else if (path.Contains("DALSQLite")) { //path = "DALSQLite"; return "SQLiteDAL"; } else if (path.Contains("PostgreSQLDAL")) { // path = "DALPostgreSQL"; return "PostgreSQLDAL"; } else if (path.Contains("OracleDAL")) { return "OracleDAL"; } else { //path = "DAL"; return "SqlServerDAL"; } } } public AbstractFactory() { } ///<summary> ///分页接口 /// </summary> ///<returns></returns> public static ISelectPage CreateSelectPage() { //ISelectPage page = new SelectPage(); //return page; string className = "GeovinDu." + dalType + ".SelectPage"; return (ISelectPage)Assembly.Load(path).CreateInstance(className); //命名空间名称GeovinDu.SqlServerDAL //path = "AcessDAL";//生成的DLL文件名 } ///<summary> ///CompanyBranch接口 /// </summary> ///<returns></returns> public static ICompanyBranch CreateCompanyBranch(string _databaseprefix, string _sysdatarolefix) { //ICompanyBranch iCompanyBranch = new CompanyBranchDAL(); //return iCompanyBranch; string className = "GeovinDu." + dalType + ".CompanyBranchDAL";//(_databaseprefix, _sysdatarolefix) return (ICompanyBranch)Assembly.Load(path).CreateInstance(className); //GeovinDu.SqlServerDAL } ///<summary> ///EnterpriseType接口 /// </summary> ///<returns></returns> public static IEnterpriseType CreateEnterpriseType(string _databaseprefix, string _sysdatarolefix) { //IEnterpriseType iEnterpriseType = new EnterpriseTypeDAL(); //return iEnterpriseType; string className = "GeovinDu." + dalType + ".EnterpriseTypeDAL"; return (IEnterpriseType)Assembly.Load(path).CreateInstance(className); } ///<summary> ///LoginDiaryList接口 /// </summary> ///<returns></returns> public static ILoginDiaryList CreateLoginDiaryList(string _databaseprefix, string _sysdatarolefix) { //ILoginDiaryList iLoginDiaryList = new LoginDiaryListDAL(); //return iLoginDiaryList; string className = "GeovinDu." + dalType + ".LoginDiaryListDAL";//(_databaseprefix, _sysdatarolefix) return (ILoginDiaryList)Assembly.Load(path).CreateInstance(className); } ///<summary> ///OperatingUser接口 ///https://msdn.microsoft.com/zh-cn/library/ms173128(VS.80).aspx ///https://stackoverflow.com/questions/2202381/reflection-how-to-invoke-method-with-parameters /// </summary> ///<returns></returns> public static IOperatingUser CreateOperatingUser(string _databaseprefix, string _sysdatarolefix) { //IOperatingUser iOperatingUser = new OperatingUserDAL(_databaseprefix, _sysdatarolefix); //return iOperatingUser; IOperatingUser iOperatingUser = null; string className = "GeovinDu." + dalType + ".OperatingUserDAL";//(_databaseprefix, _sysdatarolefix) //return (IOperatingUser)Assembly.Load(path).CreateInstance(className); //string className = "GeovinDu.SQLiteDAL.OperatingUserDAL"; //Assembly assembly = Assembly.LoadFrom(@"G:\winxp备份\PayrollPrint4\PayrollPrint\bin\Release\DALSQLite.dll"); // object oo = assembly.CreateInstance(className); //得到对象命名空间名 // MethodInfo methodinfo = assembly.GetType("GeovinDu.GeovinDu.SQLiteDAL.OperatingUserDAL").GetMethod("OperatingUserDAL"); //得到方法 //Object obj = methodinfo.Invoke(oo, new object[] { _databaseprefix, _sysdatarolefix }); //IOperatingUser iOperatingUser = (IOperatingUser)obj; object obj = Assembly.Load(path).CreateInstance(className); Type t2 = obj.GetType();// Type.GetType("GeovinDu.SQLiteDAL.OperatingUserDAL", false, true); if (t2 != null) { iOperatingUser = (OperatingUserDAL)Activator.CreateInstance(t2, new object[] { }); //Assembly.Load(path).CreateInstance(className); //值為空 } //iOperatingUser = (IOperatingUser)Activator.CreateInstance(System.Type.GetType(className)); return iOperatingUser; } ///<summary> ///PrintWordDocumentTemplateList接口 /// </summary> ///<returns></returns> public static IPrintWordDocumentTemplateList CreatePrintWordDocumentTemplateList(string _databaseprefix, string _sysdatarolefix) { //IPrintWordDocumentTemplateList iPrintWordDocumentTemplateList = new PrintWordDocumentTemplateListDAL(); //return iPrintWordDocumentTemplateList; string className = "GeovinDu." + dalType + ".PrintWordDocumentTemplateListDAL";//(_databaseprefix, _sysdatarolefix) return (IPrintWordDocumentTemplateList)Assembly.Load(path).CreateInstance(className); } /// <summary> /// /// </summary> /// <returns></returns> public static ISysConfig CreateSysConfig() { string className = "GeovinDu." + dalType + ".SysConfigDAL"; return (ISysConfig)Assembly.Load(path).CreateInstance(className); //databaseprefix = _databaseprefix; //ISysConfig iSysConfig = new DAL.SysConfigDAL(); //return iSysConfig; } }
https://github.com/fabriciorissetto/CustomActivator
https://www.codeproject.com/Articles/55710/Reflection-in-NET