Scorpio 常规性操作

什么是 Scorpio 常规性操作

Conventional 用于对应用 Assembly 中的 Type 执行一些常规操作。如：自动的依赖关系注入、Aspect 注入、Unit Of Work 注入等。

Conventional 主要由以下类、接口及方法组成：

ConventionalAction 类，用于对执行一般性操作。
ConventionalRegistrar 类，用于注册及配置 ConventionalAction 类。
ServiceCollection.AddConventionalRegistrar() 方法，用于将 ConventionalRegistrar 添加到 ConventionalRegistrar 列表中。
ServiceCollection.RegisterAssemblyByConvention() 方法，用于对指定的 Assembly 执行 ConventionalAction 操作。

在 Scorpio 中，各种自动化操作便是基于 Conventional 设计并实现的。如果您需要实现自己的一般性操作。请实现 ConventionalActionBase 抽象类及 IConventionalRegistrar 接口。以下为 Scorpio 的 Dependency Injection 组件的实现代码：

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;
using Scorpio.Conventional;
using Scorpio.DependencyInjection.Conventional;
using System.Linq.Expressions;

namespace Scorpio.DependencyInjection.Conventional
{
    internal class BasicConventionalRegistrar : IConventionalRegistrar
    {
        public void Register(IConventionalRegistrationContext context)
        {
            context.DoConventionalAction<ConventionalDependencyAction>(config =>
            {
                config
                    .Where(t => t.IsStandardType())
                    .Where(t => t.IsAssignableTo<ISingletonDependency>())
                    .AsDefault().AsSelf().Lifetime(ServiceLifetime.Singleton);
                config
                    .Where(t => t.IsStandardType())
                    .Where(t => t.IsAssignableTo<ITransientDependency>())
                    .AsDefault().AsSelf().Lifetime(ServiceLifetime.Transient);
                config
                    .Where(t => t.IsStandardType())
                    .Where(t => t.IsAssignableTo<IScopedDependency>())
                    .AsDefault().AsSelf().Lifetime(ServiceLifetime.Scoped);
                config
                    .Where(t => t.IsStandardType())
                    .Where(t => t.AttributeExists<ExposeServicesAttribute>(false))
                    .AsExposeService();
            });
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Scorpio.Conventional;

namespace Scorpio.DependencyInjection.Conventional
{
    class ConventionalDependencyAction : ConventionalActionBase
    {

        
        public ConventionalDependencyAction(IConventionalConfiguration configuration) 
            : base(configuration)
        {
        }

        protected override void Action(IConventionalContext context)
        {

            context.Types.ForEach(
                t => context.Get<ICollection<IRegisterAssemblyServiceSelector>>("Service").ForEach(
                    selector => selector.Select(t).ForEach(
                    s => context.Services.ReplaceOrAdd(
                        ServiceDescriptor.Describe(s, t, 
                        context.GetOrAdd<IRegisterAssemblyLifetimeSelector>("Lifetime", 
                        new LifetimeSelector(ServiceLifetime.Transient)).Select(t)),
                        t.GetAttribute<ReplaceServiceAttribute>()?.ReplaceService??false
                        ))));
        }
    }
}

ConventionalActionBase 类

您如果需要对类执行一些常规的操作，您首先需要继承 ConventionalActionBase 类并重写这个类的 Action(IConventionalContext context) 方法。如：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Scorpio.Conventional;

namespace Scorpio.DependencyInjection.Conventional
{
    class ConventionalDependencyAction : ConventionalActionBase
    {

        
        public ConventionalDependencyAction(IConventionalConfiguration configuration) 
            : base(configuration)
        {
        }

        protected override void Action(IConventionalContext context)
        {

            context.Types.ForEach(t=> {
                //TODO: Do something for the type.
            })
        }
    }
}

IConventionalRegistrar

在编写完成常规操作代码后，我们需要实现 IConventionalRegistrar 接口以便将编写好的操作代码注册并配置到 Conventional 中，如：

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;
using Scorpio.Conventional;
using Scorpio.DependencyInjection.Conventional;
using System.Linq.Expressions;

namespace Scorpio.DependencyInjection.Conventional
{
    internal class BasicConventionalRegistrar : IConventionalRegistrar
    {
        public void Register(IConventionalRegistrationContext context)
        {
            context.DoConventionalAction<ConventionalDependencyAction>(config =>
            {
                config.CreateContext().Where(t=>/*添加过滤条件*/);
                //或者
                config.Where(t=>/*添加过滤条件*/);//这是个快捷方法，和上面的语句等效。
            });
        }
    }
}

最后，请调用 ServiceCollection.AddConventionalRegistrar() 方法将我们的注册器添加到 Scorpio 中。注册器将在调用 ServiceCollection.RegisterAssemblyByConvention() 或者它的重载方法时被依次调用。如：

using System;
using System.Collections.Generic;
using System.Text;
using Scorpio.Modularity;
using Scorpio.DependencyInjection;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;
using Scorpio.Conventional;
using Scorpio.DependencyInjection.Conventional;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Options;
using Scorpio.Threading;
using Scorpio.Runtime;

namespace Scorpio
{
    /// <summary>
    /// 
    /// </summary>
    internal sealed class StartupModule : ScorpioModule
    {

        public override void PreConfigureServices(ConfigureServicesContext context)
        {
            context.Services.AddConventionalRegistrar(new BasicConventionalRegistrar());
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="context"></param>
        public override void ConfigureServices(ConfigureServicesContext context)
        {
            context.Services.RegisterAssemblyByConvention();
        }

    }
}

请注意：

请在 PreConfigureServices() 方法中调用 AddConventionalRegistrar() 方法，而在 ConfigureServices() 方法中调用 RegisterAssemblyByConvention() 方法，以确保在调用任何 RegisterAssemblyByConvention() 之前所有的注册器已经就绪。