Spring.NET学习笔记(1)-基本依赖注入

 不学Spring，系统照样能跑，学会了Spring会发现跟没学会之前也多大差别，一直在用Spring以后就会感觉不用Spring写程序就好像无从下手，Spring就是一容器，用以组装程序而用。

一.依赖注入

分三种方式

(1）构造注入

<object id="foo" type="X.Y.Foo, Example">  <constructor-arg ref="bar"/>  <constructor-arg ref="baz"/></object><object id="bar" type="X.Y.Bar, Example"/><object id="baz" type="X.Y.Baz, Example"/>

(2)Setter属性注入

<object id="exampleObject" type="Examples.ExampleObject, ExamplesLibrary">  <!-- setter injection using the ref attribute -->  <property name="objectOne" ref="anotherExampleObject"/>  <property name="objectTwo" ref="yetAnotherObject"/>  <property name="IntegerProperty" value="1"/></object><object id="anotherExampleObject" type="Examples.AnotherObject, ExamplesLibrary"/><object id="yetAnotherObject" type="Examples.YetAnotherObject, ExamplesLibrary"/>

(3)方法注入

3.1

public class TestObjectFactory{    public const string TheName = "Old Goriot";    public const int TheAge = 78;    public virtual object GetObject()    {        return new TestObject(TheName, TheAge);    }}

<object id='factory' type='Spring.Objects.Factory.Support.TestObjectFactory, Spring.Core.Tests'>  <lookup-method name='GetObject' object='target'/></object><object id='target' type='Spring.Objects.TestObject, Spring.Core.Tests' singleton='false'>  <property name='name' value='Fiona Apple'/>  <property name='age' value='47'/></object>

3.2方法替换

public class MyValueCalculator{    public virtual string ComputeValue(string input)    {        // ... some real code    }    // ... some other methods}public class ReplacementComputeValue : Spring.Objects.Factory.Support.IMethodReplacer{    public object Implement(object target, MethodInfo method, object[] arguments)    {        // get the input value, work with it, and return a computed result...        string value = (string)arguments[0];        // compute...        return result;    }}

将MyValueCalculator 的ComputeValue方法替换成，实现IMethodReplacer 接口的Implement方法

<object id="myValueCalculator" type="Examples.MyValueCalculator, ExampleAssembly">  <!-- arbitrary method replacement -->  <replaced-method name="ComputeValue" replacer="replacementComputeValue">    <arg-type match="String"/>  </replaced-method></object><object id="replacementComputeValue" type="Examples.ReplacementComputeValue, ExampleAssembly"/>

这个方法明显很变态，完全破坏了封装，一般很少用