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:
/// DatabaSEOperateinterface
/// </summary>
public interface IDatabase
{
string Name{ get ;}
void Select( string commandText);
void Insert( string commandText);
void Update( string commandText);
void Delete( string 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 string Name
{
get { return " sqlserver " ;}
}
public void Select( string commandText)
{
Console.WriteLine( string .Format( " '{0}'isaquerysqlin{1}! " ,commandText,Name));
}
public void Insert( string commandText)
{
Console.WriteLine( string .Format( " '{0}'isainsertsqlin{1}! " ,Name));
}
public void Update( string commandText)
{
Console.WriteLine( string .Format( " '{0}'isaupdatesqlin{1}! " ,Name));
}
public void Delete( string commandText)
{
Console.WriteLine( string .Format( " '{0}'isadeletesqlin{1}! " ,Name));
}
}
以及
{
public string Name
{
get { return " oracle " ;}
}
public void Select( string commandText)
{
Console.WriteLine( string .Format( " '{0}'isaquerysqlin{1}! " ,Name));
}
}
4)接着创建一个数据库管理器DatabaseManager.cs:
{
IDatabase_database;
public DatabaseManager(IDatabasedatabase)
{
_database = database;
}
public void Search( string commandText)
{
_database.Select(commandText);
}
public void Add( string commandText)
{
_database.Insert(commandText);
}
public void Save( string commandText)
{
_database.Update(commandText);
}
public void Remove( string commandText)
{
_database.Delete(commandText);
}
}
5)在控制台中,编写以下测试程序:
builder.RegisterType < DatabaseManager > ();
builder.RegisterType < sqlDatabase > ().As < IDatabase > ();
using (varcontainer = builder.Build())
{
varmanager = container.Resolve < DatabaseManager > ();
manager.Search( " SELECT*FORMUSER " );
}
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。
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:
< configSections >
< section name ="autofac" type ="Autofac.Configuration.SectionHandler,Autofac.Configuration" />
</ configSections >
< autofac defaultAssembly ="AutofacDemo" >
< components >
< component type ="AutofacDemo.sqlDatabase,AutofacDemo" service ="AutofacDemo.IDatabase" />
</ components >
</ autofac >
</ 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:
builder.RegisterType < DatabaseManager > ();
builder.RegisterModule( new ConfigurationSettingsReader( " autofac " ));
using (varcontainer = builder.Build())
{
varmanager = container.Resolve < DatabaseManager > ();
manager.Search( " SELECT*FORMUSER " );
}
运行结果:
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|
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:
/// IdIdentityInterface
/// </summary>
public interface Identity
{
int Id{ get ; set ;}
}
public class User:Identity
{
public int Id{ get ; set ;}
public string Name{ get ; set ;}
}
{
IDatabase_database;
User_user;
public DatabaseManager(IDatabasedatabase): this (database, null )
{
}
public DatabaseManager(IDatabasedatabase,Useruser)
{
_database = database;
_user = user;
}
/// <summary>
/// CheckAuthority
/// </summary>
/// <returns></returns>
public bool IsAuthority()
{
bool result = _user != null && _user.Id == 1 && _user.Name == " leepy " ? true : false ;
if ( ! result)
Console.WriteLine( " Notauthority! " );
return result;
}
public void Search( string commandText)
{
_database.Select(commandText);
}
public void Add( string commandText)
{
if (IsAuthority())
_database.Insert(commandText);
}
public void Save( string commandText)
{
if (IsAuthority())
_database.Update(commandText);
}
public void Remove( string commandText)
{
if (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:
varbuilder = new ContainerBuilder();
builder.RegisterModule( new ConfigurationSettingsReader( " autofac " ));
builder.RegisterInstance(user).As < User > ();
builder.Register(c => new DatabaseManager(c.Resolve < IDatabase > (),c.Resolve < User > ()));
using (varcontainer = builder.Build())
{
varmanager = container.Resolve < DatabaseManager > ();
manager.Add( " INSERTINTOUSER... " );
}
运行结果:
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。
User user = new User { Id = 2,Name = "zhangsan" };
运行结果:
说明该用户无权限操作。