关于Interface及其对应的Assembly和Class的描述信息存在以下的BusinessObjectConfiguration.config中：
<?xml version="1.0" encoding="utf-8"?><BusinessObjectConfiguration> <xmlSerializerSection type="LiteMDA.Configuration.BusinessObjectConfiguration, LiteMDA.Configuration, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"> <BusinessObjectConfiguration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <VisibleBusinessObjects> <BusinessObject> <InterfaceName>LiteMDA.BusinessObjectFactory.Test.ITestClass</InterfaceName> <Class AssemblyName="LiteMDA.BusinessObjectFactory.Test.exe" ClassName="LiteMDA.BusinessObjectFactory.Test.TestClass" /> </BusinessObject> <BusinessObject> <InterfaceName>LiteMDA.BusinessObjectFactory.Test.IGenericTestClass`2[System.String,System.Object]</InterfaceName> <Class AssemblyName="LiteMDA.BusinessObjectFactory.Test.exe" ClassName="LiteMDA.BusinessObjectFactory.Test.GenericTestClass`2[System.String,System.Object]" /> </BusinessObject> <BusinessObject> <InterfaceName>LiteMDA.BusinessObjectFactory.Test.ITestClass2</InterfaceName> <Class AssemblyName="LiteMDA.BusinessObjectFactory.Test.exe" ClassName="LiteMDA.BusinessObjectFactory.Test.GenericTestClass`2[System.String,System.Object]" /> </BusinessObject> </VisibleBusinessObjects> </BusinessObjectConfiguration> </xmlSerializerSection></BusinessObjectConfiguration>以上的Configuration中定义了三个可以被BusinessObjectFactory构造的类，构造时只需提供Interface，这里给出了三种典型的情况，一个是非Generic、一个是接口为Generic，类也为Generic，第三个是接口非Generic，类Generic。
BusinessObjectFactory的源码如下：
using System;using System.Collections.Generic;using System.Text;using System.Reflection;using LiteMDA.Configuration;using Microsoft.Practices.EnterpriseLibrary.Configuration;namespace LiteMDA.BusinessObjectFactory
{
/// <summary>
/// ObjectFactory is the only gateway for creating Business Objects.
/// </summary> public sealed class ObjectFactory { private ObjectFactory() { } /// <summary> /// _ObjectMap saves all the BOI/BO mapping pairs, this field will /// be constructed from the BOI exposing configuration file at the /// first time when the CreateObject method is invoked. /// </summary> private static BusinessObjectConfiguration _BOC = null; /// <summary> /// Create a Business Object. /// </summary> /// <typeparam name="TInterface">An exposed Business Object Interface.</typeparam> /// <returns>Return Business Object instance that implementing TInterface.</returns> /// <exception cref="LiteMDA.BusinessObjectFactory.InterfaceNotExposedException"> /// Thrown when the specified TInterface is not in the exposed interface list. /// </exception> /// <exception cref="LiteMDA.BusinessObjectFactory.ConfigurationFileFormatErrorException"> /// Thrown when the the format of the configuration file for BO/BOI mapping is error. /// </exception> public static TInterface CreateObject<TInterface>() { if (_BOC == null) { // if this is the first time invoking CreateObject, load BOI/BO // mapping pairs from the configuration file first. _BOC = ConfigurationManager.GetConfiguration("BusinessObjectConfiguration") as BusinessObjectConfiguration; } AssemblyClass ac = _BOC[typeof(TInterface).ToString()]; if (ac != null) { //create object instance from the specified assemblyName and className Assembly ass = Assembly.LoadFile(AppDomain.CurrentDomain.BaseDirectory + ac.AssemblyName); if (ac.ClassName.Contains("`")) { //It is a generic type, so fetch Type Parameters and bind then to the type before CreateInstance Type t = ass.GetType(ac.ClassName.Substring(0, ac.ClassName.IndexOf("["))); string typeParamListStr = ac.ClassName.Substring(ac.ClassName.IndexOf("[") + 1).TrimEnd(']'); string[] typeParamNames = typeParamListStr.Split(','); Type[] typeParams = new Type[typeParamNames.Length]; for (int i = 0; i < typeParamNames.Length; i++) { typeParams[i] = Type.GetType(typeParamNames[i].Trim()); } t = t.MakeGenericType(typeParams); return (TInterface)Activator.CreateInstance(t); } else { return (TInterface)ass.CreateInstance(ac.ClassName); } } else { throw new InterfaceNotExposedException(typeof(TInterface).ToString()); } } }
}几个测试类和接口代码如下：
ITestClass.cs
using System;using System.Collections.Generic;using System.Text;namespace LiteMDA.BusinessObjectFactory.Test{ public interface ITestClass { void TestMethod(); }}ITestClass2.cs
using System;using System.Collections.Generic;using System.Text;namespace LiteMDA.BusinessObjectFactory.Test{ public interface ITestClass2 { void TestMethod2(); }}IGenericTestClass.cs
using System;using System.Collections.Generic;using System.Text;namespace LiteMDA.BusinessObjectFactory.Test{ public interface IGenericTestClass<T, U> { void TestMethod(); }}TestClass.cs
using System;using System.Collections.Generic;using System.Text;namespace LiteMDA.BusinessObjectFactory.Test{ public class TestClass : ITestClass { #region ITestClass Members public void TestMethod() { System.Windows.Forms.MessageBox.Show("OK"); } #endregion }}GenericTestClass.cs
using System;using System.Collections.Generic;using System.Text;namespace LiteMDA.BusinessObjectFactory.Test{ public class GenericTestClass<T, U> : IGenericTestClass<T, U>, ITestClass2 { public void TestMethod() { System.Windows.Forms.MessageBox.Show("OK2"); } public void TestMethod2() { System.Windows.Forms.MessageBox.Show("OK3"); } }}测试代码如下：
private void btnTestCreateBusinessObject_Click(object sender, EventArgs e) { ITestClass tc = ObjectFactory.CreateObject<ITestClass>(); tc.TestMethod(); IGenericTestClass<string, object> gtc = ObjectFactory.CreateObject<IGenericTestClass<string, object>>(); gtc.TestMethod(); ITestClass2 tc2 = ObjectFactory.CreateObject<ITestClass2>(); tc2.TestMethod2(); }--
顺便说一下，以上的Configuration使用EnterpriseLibrary读写的。在vs.net 2005 beta2中使用EntLib我费了一番波折才搞定，这里说以下怎样设置，免得大家再走弯路。
你需要先用操作系统的搜索功能搜索entlib中src目录下所有包含"define VS2003"的.cs文件，大概十几个，把所有这些文件顶部的"VS2003"改成"VS2005B2"，然后用vs.net 2005 beta2（vc#2005beta2也一样）打开EnterpriseLibrary.sln重新编译所有程序集，同时请使用重新编后的Enterprise Library Configuration Tool来建立Application的App.config或web.config。
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