Dependency injection 如何使用fluent API在Kephas中注册服务?

Dependency injection 如何使用fluent API在Kephas中注册服务?,dependency-injection,kephas,Dependency Injection,Kephas,我想保留Kephas提供的DI抽象层,但在我的特殊情况下,我需要注册一个从第三方库导入的服务。鉴于此,我无法使用服务注册所需的[AppServiceContract]属性对服务进行注释。有没有办法做到这一点?有。以下是要遵循的步骤: 定义一个实现IConventionsRegistrar的类 使用约定生成器注册所需的服务 示例代码: public class MyConventionsRegistrar : IConventionsRegistrar { /// <summar

我想保留Kephas提供的DI抽象层,但在我的特殊情况下,我需要注册一个从第三方库导入的服务。鉴于此,我无法使用服务注册所需的
[AppServiceContract]
属性对服务进行注释。有没有办法做到这一点?

有。以下是要遵循的步骤:

  • 定义一个实现
    IConventionsRegistrar
    的类
  • 使用约定生成器注册所需的服务
示例代码:

public class MyConventionsRegistrar : IConventionsRegistrar
{
    /// <summary>
    /// Registers the conventions.
    /// </summary>
    /// <param name="builder">The registration builder.</param>
    /// <param name="candidateTypes">The candidate types which can take part in the composition.</param>
    /// <param name="registrationContext">Context for the registration.</param>
    public void RegisterConventions(
        IConventionsBuilder builder,
        IEnumerable<TypeInfo> candidateTypes,
        ICompositionRegistrationContext registrationContext)
    {
        //... here you can use the conventions builder to register your services using the fluent API. The candidate types are provided if you need the  identified application types. A couple of examples are provided below:

        // shared/singleton service exported as IMyService with MyService implementation.
        builder.ForType(typeof(MyServiceImpl))
               .Export(b => b.AsContractType(typeof(IMyService)))
               .Shared();

        // instance-based multiple services exported as IMultiImplService
        builder.ForTypesDerivedFrom(typeof(IMultiImplService))
               .Export(b => b.AsContractType(typeof(IMultiImplService)));
    }
这两种情况都是自动发现的,并在适当的时候调用注册方法。然而,在第二种情况下,优势在于注册可以作为服务元数据在以后查询

public class MyAppServiceInfoProvider : IAppServiceInfoProvider
{
    /// <summary>
    /// Gets an enumeration of application service information objects.
    /// </summary>
    /// <param name="candidateTypes">The candidate types which can take part in the composition.</param>
    /// <param name="registrationContext">Context for the registration.</param>
    /// <returns>
    /// An enumeration of application service information objects and their associated contract type.
    /// </returns>
    public IEnumerable<(TypeInfo contractType, IAppServiceInfo appServiceInfo)> GetAppServiceInfos(IEnumerable<TypeInfo> candidateTypes, ICompositionRegistrationContext registrationContext)
    {
        yield return (typeof(IMyService).GetTypeInfo(), 
                      new AppServiceInfo(typeof(IMyService), 
                                         typeof(MyServiceImpl),
                                         AppServiceLifetime.Shared));
        yield return (typeof(IMultiImplService).GetTypeInfo(), 
                      new AppServiceInfo(typeof(IMultiImplService), 
                                         AppServiceLifetime.Instance, 
                                         allowMultiple: true));
    }