依赖注入框架Autofac的简单使用

Autofac是一款IOC框架，比较于其他的IOC框架，如Spring.NET，Unity，Castle等等所包含的，它很轻量级性能上也是很高的。于是，今天抽空研究了下它。下载地址： http://code.google.com/p/autofac/downloads/list

1）解压它的压缩包，主要看到Autofac.dll，Autofac.Configuration.dll，这也是本篇文章重点使用的Autofac的类库。

2）创建一个控制台工程，并且引用以上的DLL文件。创建一个数据库操作接口IDatabase.cs：

/// <summary>
/// DatabaSEOperateinterface
/// </summary>
public @H_403_35@ interface @H_403_35@IDatabase
{
string @H_403_35@Name{ get @H_403_35@;}

void @H_403_35@Select( string @H_403_35@commandText);

void @H_403_35@Insert( string @H_403_35@commandText);

void @H_403_35@Update( string @H_403_35@commandText);

void @H_403_35@Delete( string @H_403_35@commandText);
}

这里包含CRUD四种操作的方法。

3）创建两种数据库的操作类，sqlDatabase.cs以及OracleDatabase.cs：

public @H_403_35@ class @H_403_35@sqlDatabase:IDatabase
{
public @H_403_35@ string @H_403_35@Name
{
get @H_403_35@{ return @H_403_35@ " sqlserver " @H_403_35@;}
}

public @H_403_35@ void @H_403_35@Select( string @H_403_35@commandText)
{
Console.WriteLine( string @H_403_35@.Format( " '{0}'isaquerysqlin{1}! " @H_403_35@,commandText,Name));
}

public @H_403_35@ void @H_403_35@Insert( string @H_403_35@commandText)
{
Console.WriteLine( string @H_403_35@.Format( " '{0}'isainsertsqlin{1}! " @H_403_35@,Name));
}

public @H_403_35@ void @H_403_35@Update( string @H_403_35@commandText)
{
Console.WriteLine( string @H_403_35@.Format( " '{0}'isaupdatesqlin{1}! " @H_403_35@,Name));
}

public @H_403_35@ void @H_403_35@Delete( string @H_403_35@commandText)
{
Console.WriteLine( string @H_403_35@.Format( " '{0}'isadeletesqlin{1}! " @H_403_35@,Name));
}
}

以及

public @H_403_35@ class @H_403_35@OracleDatabase:IDatabase
{
public @H_403_35@ string @H_403_35@Name
{
get @H_403_35@{ return @H_403_35@ " oracle " @H_403_35@;}
}

public @H_403_35@ void @H_403_35@Select( string @H_403_35@commandText)
{
Console.WriteLine( string @H_403_35@.Format( " '{0}'isaquerysqlin{1}! " @H_403_35@,Name));
}
}

4）接着创建一个数据库管理器DatabaseManager.cs：

public @H_403_35@ class @H_403_35@DatabaseManager
{
IDatabase_database;

public @H_403_35@DatabaseManager(IDatabasedatabase)
{
_database @H_403_35@= @H_403_35@database;
}

public @H_403_35@ void @H_403_35@Search( string @H_403_35@commandText)
{
_database.Select(commandText);
}

public @H_403_35@ void @H_403_35@Add( string @H_403_35@commandText)
{
_database.Insert(commandText);
}

public @H_403_35@ void @H_403_35@Save( string @H_403_35@commandText)
{
_database.Update(commandText);
}

public @H_403_35@ void @H_403_35@Remove( string @H_403_35@commandText)
{
_database.Delete(commandText);
}

}

5）在控制台中，编写以下测试程序：

@H_403_35@varbuilder @H_403_35@= @H_403_35@ new @H_403_35@ContainerBuilder();
builder.RegisterType @H_403_35@< @H_403_35@DatabaseManager @H_403_35@> @H_403_35@();
builder.RegisterType @H_403_35@< @H_403_35@sqlDatabase @H_403_35@> @H_403_35@().As @H_403_35@< @H_403_35@IDatabase @H_403_35@> @H_403_35@();
using @H_403_35@(varcontainer @H_403_35@= @H_403_35@builder.Build())
{
varmanager @H_403_35@= @H_403_35@container.Resolve @H_403_35@< @H_403_35@DatabaseManager @H_403_35@> @H_403_35@();
manager.Search( " SELECT*FORMUSER " @H_403_35@);
}

运行结果：

分析：

这里通过ContainerBuilder方法RegisterType对DatabaseManager进行注册，当注册的类型在相应得到的容器中可以Resolve你的DatabaseManager实例。

builder.RegisterType<sqlDatabase>().As<IDatabase>();通过AS可以让DatabaseManager类中通过构造函数依赖注入类型相应的接口。

Build()方法生成一个对应的Container实例，这样，就可以通过Resolve解析到注册的类型实例。

同样地，如果你修改数据库类型注册为：

builder.RegisterType<OracleDatabase>().As<IDatabase>();

运行结果：

6）显然以上的程序中，sqlDatabase或者OracleDatabase已经暴露于客户程序中了，现在我想将该类型选择通过文件配置进行读取。Autofac自带了一个Autofac.Configuration.dll 非常方便地对类型进行配置，避免了程序的重新编译。

修改App.config：

< configuration > @H_403_35@
< configSections > @H_403_35@
< section name ="autofac" type ="Autofac.Configuration.SectionHandler,Autofac.Configuration" /> @H_403_35@
</ configSections > @H_403_35@
< autofac defaultAssembly ="AutofacDemo" > @H_403_35@
< components > @H_403_35@
< component type ="AutofacDemo.sqlDatabase,AutofacDemo" service ="AutofacDemo.IDatabase" /> @H_403_35@
</ components > @H_403_35@
</ autofac > @H_403_35@
</ configuration >

通过Autofac.Configuration.SectionHandler配置节点对组件进行处理。

对应的客户端程序改为：

@H_403_35@varbuilder @H_403_35@= @H_403_35@ new @H_403_35@ContainerBuilder();
builder.RegisterType @H_403_35@< @H_403_35@DatabaseManager @H_403_35@> @H_403_35@();
builder.RegisterModule( new @H_403_35@ConfigurationSettingsReader( " autofac " @H_403_35@));
using @H_403_35@(varcontainer @H_403_35@= @H_403_35@builder.Build())
{
varmanager @H_403_35@= @H_403_35@container.Resolve @H_403_35@< @H_403_35@DatabaseManager @H_403_35@> @H_403_35@();
manager.Search( " SELECT*FORMUSER " @H_403_35@);
}

运行结果：

7）另外还有一种方式，通过Register方法进行注册：

 
         var 
          builder =  
         new 
          ContainerBuilder();  
        
         //builder.RegisterType<DatabaseManager>();  
        
         builder.RegisterModule( 
         new 
         ConfigurationSettingsReader( 
         "autofac" 
         ));  
        
         builder.Register(c =>  
         new 
         DatabaseManager(c.Resolve<IDatabase>()));  
        
         using 
          ( 
         var 
         container = builder.Build())  
        
         {  
        
         var 
         manager = container.Resolve<DatabaseManager>();  
        
         manager.Search( 
         "SELECT * FORM USER" 
         );  
        
         }

得到结果也是一样的。

8）现在我想通过一个用户类来控制操作权限，比如增删改的权限，创建一个用户类：

/// <summary>
/// IdIdentityInterface
/// </summary>
public @H_403_35@ interface @H_403_35@Identity
{
int @H_403_35@Id{ get @H_403_35@; set @H_403_35@;}
}

public @H_403_35@ class @H_403_35@User:Identity
{
public @H_403_35@ int @H_403_35@Id{ get @H_403_35@; set @H_403_35@;}
public @H_403_35@ string @H_403_35@Name{ get @H_403_35@; set @H_403_35@;}
}

修改DatabaseManager.cs代码：

public @H_403_35@ class @H_403_35@DatabaseManager
{
IDatabase_database;
User_user;

public @H_403_35@DatabaseManager(IDatabasedatabase): this @H_403_35@(database, null @H_403_35@)
{
}

public @H_403_35@DatabaseManager(IDatabasedatabase,Useruser)
{
_database @H_403_35@= @H_403_35@database;
_user @H_403_35@= @H_403_35@user;
}

/// <summary>
/// CheckAuthority
/// </summary>
/// <returns></returns>
@H_403_35@ public @H_403_35@ bool @H_403_35@IsAuthority()
{
bool @H_403_35@result @H_403_35@= @H_403_35@_user @H_403_35@!= @H_403_35@ null @H_403_35@ @H_403_35@&& @H_403_35@_user.Id @H_403_35@== @H_403_35@ 1 @H_403_35@ @H_403_35@&& @H_403_35@_user.Name @H_403_35@== @H_403_35@ " leepy " @H_403_35@ @H_403_35@? @H_403_35@ true @H_403_35@: false @H_403_35@;
if @H_403_35@( @H_403_35@! @H_403_35@result)
Console.WriteLine( " Notauthority! " @H_403_35@);

return @H_403_35@result;
}

public @H_403_35@ void @H_403_35@Search( string @H_403_35@commandText)
{
_database.Select(commandText);
}

public @H_403_35@ void @H_403_35@Add( string @H_403_35@commandText)
{
if @H_403_35@(IsAuthority())
_database.Insert(commandText);
}

public @H_403_35@ void @H_403_35@Save( string @H_403_35@commandText)
{
if @H_403_35@(IsAuthority())
_database.Update(commandText);
}

public @H_403_35@ void @H_403_35@Remove( string @H_403_35@commandText)
{
if @H_403_35@(IsAuthority())
_database.Delete(commandText);
}
}

在构造函数中增加了一个参数User，而Add,Save,Remove增加了权限判断。

修改客户端程序：

@H_403_35@Useruser @H_403_35@= @H_403_35@ new @H_403_35@User{Id @H_403_35@= @H_403_35@ 1 @H_403_35@,Name @H_403_35@= @H_403_35@ " leepy " @H_403_35@};
varbuilder @H_403_35@= @H_403_35@ new @H_403_35@ContainerBuilder();
builder.RegisterModule( new @H_403_35@ConfigurationSettingsReader( " autofac " @H_403_35@));
builder.RegisterInstance(user).As @H_403_35@< @H_403_35@User @H_403_35@> @H_403_35@();
builder.Register(c @H_403_35@=> @H_403_35@ new @H_403_35@DatabaseManager(c.Resolve @H_403_35@< @H_403_35@IDatabase @H_403_35@> @H_403_35@(),c.Resolve @H_403_35@< @H_403_35@User @H_403_35@> @H_403_35@()));

using @H_403_35@(varcontainer @H_403_35@= @H_403_35@builder.Build())
{
varmanager @H_403_35@= @H_403_35@container.Resolve @H_403_35@< @H_403_35@DatabaseManager @H_403_35@> @H_403_35@();

manager.Add( " INSERTINTOUSER... " @H_403_35@);
}

运行结果：

分析：

builder.RegisterInstance(user).As<User>();注册User实例。

builder.Register(c => new DatabaseManager(c.Resolve<IDatabase>(),c.Resolve<User>()));通过Lampda表达式注册DatabaseManager实例。

如果这里我修改User的属性值：

User user = new User { Id = 2,Name = "zhangsan" };

运行结果：

说明该用户无权限操作。

依赖注入框架Autofac的简单使用

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