NBearV3 IoC 基礎教學：Web 應用服務定義、Castle 容器配置與依賴注入實戰

教學目標

掌握 NBearV3 IoC 模組基本開發流程，包含實體設計、服務介面定義、實作類別、Castle 容器配置與服務調用。

專案結構建立

1. 空白方案 + 4 個專案：
   EntityDesigns（設計實體）、Entities（生成實體）、ServiceInterfaces（服務介面）、ServiceImpls（服務實作）
   + 1 個 website (ASP.NET Web 應用)
2. 刪除預設 Class1.cs

Step 1：從現有資料庫生成設計實體

1. 執行 NBear.Tools.DbToEntityDesign.exe
2. 連線字串：Server=(local);Database=Northwind;Uid=sa;Pwd=sa
3. 選擇 Tables：Categories, Products；Views：Products by Category
4. 點擊 Generate Entities Design → 複製程式碼

Step 2：修飾設計實體

加入 MappingName 與關聯屬性

[MappingName("Categories")]
public interface Category : Entity {
    [PrimaryKey] int CategoryID { get; }
    [SqlType("nvarchar(15)")] string CategoryName { get; set; }
    [SqlType("ntext")] string Description { get; set; }
    byte[] Picture { get; set; }

    [FkQuery("Category", OrderBy="{ProductName}", Contained=true, LazyLoad=true)]
    Product[] Products { get; set; }
}

[MappingName("Products")]
public interface Product : Entity {
    [PrimaryKey] int ProductID { get; }
    [SqlType("nvarchar(40)")] string ProductName { get; set; }
    int SupplierID { get; set; }
    int CategoryID { get; set; }
    [SqlType("nvarchar(20)")] string QuantityPerUnit { get; set; }
    decimal UnitPrice { get; set; }
    short UnitsInStock { get; set; }
    short UnitsOnOrder { get; set; }
    short ReorderLevel { get; set; }
    bool Discontinued { get; set; }

    [FkReverseQuery(LazyLoad=false)]
    [MappingName("CategoryID")]
    Category Category { get; set; }
}

[ReadOnly]
[MappingName("Products by Category")]
public interface ProductsByCategory : Entity {
    [SqlType("nvarchar(15)")] string CategoryName { get; }
    [SqlType("nvarchar(40)")] string ProductName { get; }
    [SqlType("nvarchar(20)")] string QuantityPerUnit { get; }
    short UnitsInStock { get; }
    bool Discontinued { get; }
}

注意： 循環關聯時勿同時設 LazyLoad=false，否則導致死循環。

Step 3：生成實體程式碼與配置

1. 編譯 EntityDesigns
2. 執行 EntityDesignToEntity.exe 載入 DLL
3. Generate Entities → Entities\Entities.cs（加入 NBear.Common.dll 參考）
4. Generate Configuration → website\EntityConfig.xml

Step 4：Gateway 存取資料庫（非 IoC 方式）

Web.config 配置

<configSections>
  <section name="entityConfig" type="NBear.Common.EntityConfigurationSection, NBear.Common" />
</configSections>
<entityConfig>
  <includes> <add key="Sample Entity Config" value="~/EntityConfig.xml" /> </includes>
</entityConfig>
<connectionStrings>
  <add name="Northwind" connectionString="Server=(local);Database=Northwind;Uid=sa;Pwd=sa" providerName="NBear.Data.SqlServer.SqlDbProvider" />
</connectionStrings>

程式碼存取

Gateway gateway = new Gateway("Northwind");
Category[] categories = gateway.FindArray<Category>(WhereClip.All, OrderByClip.Default);

Step 5：定義服務介面與實作

ServiceInterfaces 專案（參考 NBear.Common.dll, NBear.IoC.dll, Entities）

public interface ICategoryService : IService {
    Category[] GetAllCategories();
    Category GetCategoryByID(int categoryID);
}

public interface IProductService : IService {
    Product[] GetAllProducts();
    Product GetProductByID(int productID);
}

服務介面必須繼承 IService。

ServiceImpls 專案（參考 Entities, ServiceInterfaces, NBear.Common/Data/IoC）

public class CategoryService : ICategoryService {
    public Category[] GetAllCategories() {
        return Gateway.Default.FindArray<Category>(WhereClip.All, OrderByClip.Default);
    }
    public Category GetCategoryByID(int categoryID) {
        return Gateway.Default.Find<Category>(categoryID);
    }
}

public class ProductService : IProductService {
    public Product[] GetAllProducts() {
        return Gateway.Default.FindArray<Product>(WhereClip.All, OrderByClip.Default);
    }
    public Product GetProductByID(int productID) {
        return Gateway.Default.Find<Product>(productID);
    }
}

Step 6：Castle 容器配置與服務調用

Web.config 加入 castle 區段

<configSections>
  <section name="castle" type="Castle.Windsor.Configuration.AppDomain.CastleSectionHandler, Castle.Windsor" />
  <section name="entityConfig" ... />
</configSections>
<castle>
  <components>
    <component id="category service" service="ServiceInterfaces.ICategoryService, ServiceInterfaces" type="ServiceImpls.CategoryService, ServiceImpls" />
    <component id="product service" service="ServiceInterfaces.IProductService, ServiceInterfaces" type="ServiceImpls.ProductService, ServiceImpls" />
  </components>
</castle>

Default.aspx.cs 調用服務

protected void Page_Load(object sender, EventArgs e) {
    ServiceFactory factory = ServiceFactory.Create();
    
    IProductService ps = factory.GetService<IProductService>();
    Product[] products = ps.GetAllProducts();
    WriteLine($"Got all products, {products.Length} in total.");
    
    ICategoryService cs = factory.GetService<ICategoryService>();
    Category[] categories = cs.GetAllCategories();
    WriteLine($"Got all categories, {categories.Length} in total.");
    
    foreach (Category item in categories) {
        WriteLine($"ID={item.CategoryID}, Name={item.CategoryName}, Products in category: {item.Products.Length}.");
    }
}

關鍵概念：ServiceFactory 單例模式

ServiceFactory.Create() 內部為單例，隨處呼叫皆取得同一實例。服務實作間互相調用時，只需引用 ServiceInterfaces，避免實作相依，耦合度降至最低。

部署注意

Website 不需參考 ServiceImpls，但需將 ServiceImpls.dll 複製至 Website 的 Bin 目錄，供 Castle 容器動態載入。