三层架构

一、架构图

二、解决方案中的项目设计

AbstractFactory（抽象工厂）

IBLL（业务逻辑层）

BLL

IDAL（数据访问层）

SqlServerDAL（SqlServer数据访问）

````

Model（数据模型）

ToolsLibrary（工具类）

WebMVCApplication（Web MVC应用程序）

三、具体的实现

1、AbstractFactory

（1）Cache.cs 反射出实例很耗费性能，这里使用缓存来减轻负担

/// <summary>
/// 抽象工厂的实现，因为反射出实例很耗费性能，所以运用了缓存来减轻负担
/// </summary>
public class Cache
{
    public Cache()
    {

    }
    /// <summary>
    /// 获取缓存数据
    /// </summary>
    /// <param name="key">key</param>
    /// <returns></returns>
    public static object Get(string key)
    {
        System.Web.Caching.Cache cache = HttpRuntime.Cache;
        return cache.Get(key);
    }
    /// <summary>
    /// 添加缓存数据
    /// </summary>
    /// <param name="key">key</param>
    /// <param name="value">value</param>
    public static void InsertCache(string key, object value)
    {
        if (Get(key) == null)
        {
            System.Web.Caching.Cache cache = HttpRuntime.Cache;
            cache.Insert(key, value);
        }
    }
}

（2）DALFactory.cs 反射DAL,使用IOC依赖注入

public class DALFactory
{
    /// <summary>
    /// DLL全路径
    /// </summary>
    public static readonly string DALPath = System.Configuration.ConfigurationManager.AppSettings["DALPath"];
    public static object CreateDAL(string assemblyPath, string objType)
    {
        var cacheDAL = Cache.Get(objType);
        if (cacheDAL == null)
        {
            cacheDAL = Assembly.Load(assemblyPath).CreateInstance(objType);
            Cache.InsertCache(objType, cacheDAL);
        }
        return cacheDAL;
    }
    public static IDAL.IExample GetExampleDAL()
    {
        return CreateDAL(DALPath, string.Format("{0}.Example", DALPath)) as IDAL.IExample;
    }
}

2、IBLL

public interface IExampleService
{
int Add(Model.Example model);

}

3、BLL

public class ExampleService : IBLL.IExampleService
{
    public ExampleService()
    {
        this.exampleDAL = AbstractFactory.DALFactory.GetExampleDAL();
    }
    /// <summary>
    /// 数据表数据访问层接口
    /// </summary>
    private IDAL.IExample exampleDAL;
    public IDAL.IExample ExampleDAL
    {
        set { exampleDAL = value; }
        get { return exampleDAL; }
    }
    public int Add(Model.Example model)
    {
        return exampleDAL.Add(model);
    }

}

4、IDAL

/// <summary>
/// 接口层 IExample
/// </summary>
public interface IExample
{
    #region 成员方法
    /// <summary>
    /// 增加一条记录
    /// </summary>
    /// <param name="model"></param>
    /// <returns></returns>
    int Add(Model.Example model);
    #endregion

}

5、SqlServerDAL

public class Example:IDAL.IExample
{
    public int Add(Model.Example model)
    {
        return 0;
    }
}

6、Model

/// <summary>
/// Example:实体类
/// </summary>
[Serializable]
public class Example
{
    private string _id = "";
    private string _name = "";
    /// <summary>
    /// ID
    /// </summary>
    public string ID
    {
        set { _id = value; }
        get { return _id; }
    }
    /// <summary>
    /// Name
    /// </summary>
    public string Name
    {
        set { _name = value; }
        get { return _name; }
    }

}

7、Web.config