using System;
using System.Collections;
using System.Reflection;
using CSFrameworkV4_5.Core;
using CSFrameworkV4_5.Core.CodeGenerator;
using CSFrameworkV4_5.Server.DataAccess.DAL_Base;
namespace CSFrameworkV4_5.Server.DataAccess
{
/// <summary>
/// 加载的DAL数据访问层的类型，注意：此类必须放在数据访问层模块
/// </summary>
public static class DALTypeLoader
{
//哈希表, 保存已加载的DAL类的引用地址
private static Hashtable _LoadedDalTypes =
null;
//数据访问层的程序集
private static Assembly _DALAssembly =
null;
/// <summary>
/// 数据访问层的程序集
/// </summary>
public static Assembly DALAssembly
{
get
{
if (DALTypeLoader._DALAssembly ==
null)
DALTypeLoader._DALAssembly =
typeof(DALTypeLoader).Assembly;
return DALTypeLoader._DALAssembly;
}
}
static DALTypeLoader()
{
_LoadedDalTypes =
new Hashtable();
}
/// <summary>
/// 跟据DAL类名创建数据层实例
/// </summary>
/// <param name="derivedClassName">DAL类名，如：CSFrameworkV4_5.Server.DataAccess.DAL_Business.dalSO</param>
/// <returns></returns>
internal static Type GetDALTypeByClassName(
string derivedClassName)
{
Type T = DALTypeLoader.DALAssembly.GetType(derivedClassName,
true,
true);
return T;
}
/// <summary>
/// 根据表名获取对应的DAL层
/// </summary>
/// <param name="tableName">表名</param>
/// <returns></returns>
internal static Type GetDALTypeByTableName(
string tableName)
{
Type _DAL_Type =
null;
#region 获取DAL的Type类型
//哈希表存在该类,从哈希表取出.
if (_LoadedDalTypes.ContainsKey(tableName))
_DAL_Type = _LoadedDalTypes[tableName]
as Type;
else
{
//获取DataAccess程序集中所有Public类
Type[] types =
DALTypeLoader.DALAssembly.GetExportedTypes();
//枚举程序集中所有Public类
foreach (Type T
in types)
{
//只查找dalBaseDataDict的子类
if (
false == T.IsSubclassOf(
typeof(dalBaseDataDict)))
continue;
//查找DefaultORM_UpdateMode特性
object[] atts = T.GetCustomAttributes(
typeof(DefaultORM_UpdateMode),
false);
if ((atts ==
null) || (atts.Length ==
0))
continue;
//该类有定义DefaultORM_UpdateMode特性
DefaultORM_UpdateMode att = atts[
0]
as DefaultORM_UpdateMode;
if (ORM_Tools.GetTableName(att.ORM) ==
tableName)
{
_DAL_Type =
T;
break;
}
}
//第一次加载后添加到哈希表中, 基于性能优化.
if (_DAL_Type !=
null) _LoadedDalTypes.Add(tableName, _DAL_Type);
}
#endregion
return _DAL_Type;
}
/// <summary>
/// 根据ORM模型类全名获取对应的DAL层
/// </summary>
/// <param name="ORM_TypeName"></param>
/// <returns></returns>
internal static Type GetDALTypeByORM(
string ORM_TypeName)
{
Type _DAL_Type =
null;
#region 获取_DAL_Type
//哈希表存在该类,从哈希表取出.
if (_LoadedDalTypes.ContainsKey(ORM_TypeName))
_DAL_Type = _LoadedDalTypes[ORM_TypeName]
as Type;
else
{
//
//哈希表不存在,表示第一次加载,需要从CSFrameworkV4_5.Server.DataAccess程序集中查询该类
//
//获取DataAccess程序集中所有Public类
Type[] types =
DALTypeLoader.DALAssembly.GetExportedTypes();
//枚举程序集中所有Public类
foreach (Type T
in types)
{
//只查找dalBaseDataDict的子类
if (
false == T.IsSubclassOf(
typeof(dalBaseDataDict)))
continue;
//查找DefaultORM_UpdateMode特性
object[] atts = T.GetCustomAttributes(
typeof(DefaultORM_UpdateMode),
false);
if ((atts ==
null) || (atts.Length ==
0))
continue;
//该类有定义DefaultORM_UpdateMode特性
DefaultORM_UpdateMode att = atts[
0]
as DefaultORM_UpdateMode;
if (
false == att.IsOverrideClass)
continue;
//仅查找具体类(子类)
//比较ORM的全名是否相同
if (att.ORM.FullName.ToUpper() ==
ORM_TypeName.ToUpper())
{
_DAL_Type =
T;
break;
}
}
//第一次加载后添加到哈希表中, 基于性能优化.
if (_DAL_Type !=
null) _LoadedDalTypes.Add(ORM_TypeName, _DAL_Type);
}
#endregion
return _DAL_Type;
}
}
}
转载于:https://www.cnblogs.com/Jeely/p/11350431.html
