Spring.NET學習筆記7——依賴對象的注入(基礎篇)

　　一、屬性注入

　　上篇我們簡單提到依賴注入的用途。回顧一下所講內容，發現在object節點下使用了<property name="Tool" ref="computer"/>。而property 標籤正是用來屬性注入的。而ref是用來標識是關聯到哪個object。而name屬性是指屬性名。如下：<object id="modernPerson" type="SpringNetIoC.ModernPerson, SpringNetIoC">
        <property name="Tool" ref="computer"/>
</object>

值類型的注入是需要使用property 節點的value屬性。如<property name="Name" value="Liu Dong"/>

作爲內聯類型可以使用如下：
<property name="Friend">
          <object type="SpringNetDi.Person, SpringNetDi"/>
</property>
同理，內聯類型可以是循環引用的對象(見代碼處)。

　　二、構造函數注入

構造器注入使用constructor-arg標籤作爲標識。同樣具有於屬性注入相同的方式，使用name、ref、value作爲構造器注入的屬性，如下：
<constructor-arg name="argPerson" ref="person"/>
<constructor-arg name="intProp" value="1"/>

 

　　程序的代碼如下：

public class Person { public string Name { get; set; } public int Age { get; set; } public Person Friend { get; set; } }

public class PersonDao { private Person argPerson; private int intProp; public PersonDao(Person argPerson, int intProp) { this.argPerson = argPerson; this.intProp = intProp; } public void Get() { //構造函數注入的整型參數 Console.WriteLine(string.Format("intProp:{0}", intProp)); //構造函數注入的Person Console.WriteLine(string.Format("argPerson Name:{0}", argPerson.Name)); Console.WriteLine(string.Format("argPerson Age:{0}", argPerson.Age)); //內聯對象Friend Console.WriteLine(string.Format("argPerson Friend Name:{0}", argPerson.Friend.Name)); Console.WriteLine(string.Format("argPerson Friend Age:{0}", argPerson.Friend.Age)); //內聯對象的循環引用 Console.WriteLine(string.Format("argPerson Friend Friend Name:{0}", argPerson.Friend.Friend.Name)); Console.WriteLine(string.Format("argPerson Friend Friend Age:{0}", argPerson.Friend.Friend.Age)); } }

<?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <sectionGroup name="spring"> <section name="context" type="Spring.Context.Support.ContextHandler, Spring.Core" /> <section name="objects" type="Spring.Context.Support.DefaultSectionHandler, Spring.Core" /> </sectionGroup> </configSections> <spring> <context> <resource uri="config://spring/objects" /> </context> <objects xmlns="http://www.springframework.net"> <object id="person" type="SpringNetDi.Person, SpringNetDi"> <!--屬性值類型注入--> <property name="Name" value="Liu Dong"/> <property name="Age" value="27"/> <!--內聯對象注入--> <property name="Friend"> <object type="SpringNetDi.Person, SpringNetDi"> <property name="Name" value="Beggar"/> <property name="Age" value="23"/> <property name="Friend" ref="person"/> </object> </property> </object> <object id="personDao" type="SpringNetDi.PersonDao, SpringNetDi"> <!--構造器注入--> <constructor-arg name="argPerson" ref="person"/> <constructor-arg name="intProp" value="1"/> </object> </objects> </spring> </configuration>

class Program { static void Main(string[] args) { IApplicationContext ctx = ContextRegistry.GetContext(); PersonDao dao = ctx.GetObject("personDao") as PersonDao; dao.Get(); Console.ReadLine(); } }

    

代碼下載