NHibernate Step By Step(8)数据过滤器

1.定义过滤器

<filter-def name="LiveFilter">
     <filter-param name="LiveParam" type="boolean"/>
 </filter-def>
 
 <filter-def name="LiveFilter2">
     <filter-param name="LiveParam2" type="string"/>
 </filter-def>

2.在映射文件中使用过滤器

犹如在hql中下查询语句

<class name="TestClass">
     <id name="Id" column="id">
         <generator class="assigned" />
     </id>
     <property name="Name" type="StringClob" length="100000" />
 
     <property name="Live" type="Boolean" />
     <filter name="LiveFilter" condition=":LiveParam = Live"/>
     <filter name="LiveFilter2"><![CDATA[Name = :LiveParam2]]></filter>
 </class>

3.在配置文件中获取过滤器

public void FilterDefinitionsLoadedCorrectly()
 {
     Configuration cfg = new Configuration();
     cfg.AddResource(mappingCfg, this.GetType().Assembly);
     Assert.AreEqual(cfg.FilterDefinitions.Count, 2);
 
     Assert.IsTrue(cfg.FilterDefinitions.ContainsKey("LiveFilter"));
 
     FilterDefinition f = cfg.FilterDefinitions["LiveFilter"];
 
     Assert.AreEqual(f.ParameterTypes.Count, 1);
 
     BooleanType t = f.ParameterTypes["LiveParam"] as BooleanType;
 
     Assert.IsNotNull(t); //ensure that the parameter is the correct type. 
 }

4.启动过滤器

ISession</TT对象中会用到的方法有： class=literal EnableFilter(string filterName), GetEnabledFilter(string filterName), 和 DisableFilter(string filterName). ISession 中默认是不启用过滤器的，必须通过ISession.EnableFilter()方法显式的启用。 该方法返回被启用的IFilter的实例

通过启用EnableFilter方法启用过滤器

public void FiltersLoaded()
 {
     Configuration cfg = new Configuration();
     cfg.AddResource(mappingCfg, this.GetType().Assembly);
 
     ISessionFactory factory = cfg.BuildSessionFactory();
 
     ISession session = factory.OpenSession();
 
     IFilter filter = session.EnableFilter("LiveFilter");
 
     Assert.AreEqual(filter.FilterDefinition.FilterName, "LiveFilter");
 
     filter.SetParameter("LiveParam", true);
 
     filter.Validate(); // make sure that everything is set up right. 
 
     IFilter filter2 = session.EnableFilter("LiveFilter2");
 
     filter2.SetParameter("LiveParam2", "somename");
 
     filter2.Validate();
 }

IFilter接口