ABP的动态WebApi实现了直接对服务层的调用（其实病没有跨过ApiController,只是将ApiController公共化，对于这一点的处理类似于MVC，对服务端的 调用没有跨过HttpHandler一样），这样不仅减少了ApiController的开发，也更能体现驱动领域设计的层结构。
对WebApi服务的替换与路由配置
AbpWebApiModule是Abp.Web.Api的模块类，该类中定义InitializeAspNetServices，InitializeRoutes两个方法，并且在模块的Initialize方法中执行，这两个方法分别是对WebApi的服务的替换与路由的配置，。这两处对WebApi的变更才使得直接调用服务层成为可能。
private static void InitializeAspNetServices()
{
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector), new AbpHttpControllerSelector(GlobalConfiguration.Configuration));
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpActionSelector), new AbpApiControllerActionSelector());
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerActivator), new AbpControllerActivator());
} private static void InitializeRoutes()
{
DynamicApiRouteConfig.Register();
} public static void Register()
{
//Dynamic Web APIs (with area name)
GlobalConfiguration.Configuration.Routes.MapHttpRoute(
name: "AbpDynamicWebApi",
routeTemplate: "api/services/{*serviceNameWithAction}"
);
}
对服务的分析与缓存
再对服务信息的存储上，作者提供了DynamicApiControllerInfo，DynamicApiActionInfo（源码中的DynamicApiMethodInfo.cs），其中DynamicApiControllerInfo包含了一DynamicApiActionInfo集合。
internal class DynamicApiControllerInfo
{
/// <summary>
/// Name of the service.
/// </summary>
public string ServiceName { get; private set; } /// <summary>
/// Controller type.
/// </summary>
public Type Type { get; private set; } /// <summary>
/// Dynamic Action Filters for this controller.
/// </summary>
public IFilter[] Filters { get; set; } /// <summary>
/// All actions of the controller.
/// </summary>
public IDictionary<string, DynamicApiActionInfo> Actions { get; private set; } /// <summary>
/// Creates a new <see cref="DynamicApiControllerInfo"/> instance.
/// </summary>
/// <param name="serviceName">Name of the service</param>
/// <param name="type">Controller type</param>
/// <param name="filters">Filters</param>
public DynamicApiControllerInfo(string serviceName, Type type, IFilter[] filters = null)
{
ServiceName = serviceName;
Type = type;
Filters = filters ?? new IFilter[] { }; //Assigning or initialzing the action filters. Actions = new Dictionary<string, DynamicApiActionInfo>(StringComparer.InvariantCultureIgnoreCase);
}
}
在执行AbpHttpControllerSelector, AbpApiControllerActionSelector, AbpControllerActivator的时候，系统已经在初始化的时候对服务层进行了分析与缓存。
在作者给的Demo SimpleTaskSystem下有一模块类SimpleTaskSystemWebApiModule
[DependsOn(typeof(AbpWebApiModule))] //We declare depended modules explicitly
public class SimpleTaskSystemWebApiModule : AbpModule
{
public override void Initialize()
{
//This code is used to register classes to dependency injection system for this assembly using conventions.
IocManager.RegisterAssemblyByConvention(Assembly.GetExecutingAssembly()); //Creating dynamic Web Api Controllers for application services.
//Thus, 'web api layer' is created automatically by ABP. DynamicApiControllerBuilder
.ForAll<IApplicationService>(Assembly.GetAssembly(typeof (SimpleTaskSystemApplicationModule)), "tasksystem")
.Build();
}
}
在这里是使用到了DynamicApiControllerBuilder，这个类主要是对服务接口进行一个注册，再由IBatchApiControllerBuilder按照注册的服务接口对提供的程序集进行分析。
DynamicApiControllerBuilder提供的ForAll只是返回的一个IBatchApiControllerBuilder实现对象
public static IBatchApiControllerBuilder<T> ForAll<T>(Assembly assembly, string servicePrefix)
{
return new BatchApiControllerBuilder<T>(assembly, servicePrefix);
}
这个方法为BatchApiControllerBuilder提供了服务接口与服务接口与需要分析的程序集，以及服务地址前缀。
BatchApiControllerBuilder从程序集中获取实现服务接口的非抽象类。BatchApiControllerBuilder再通过DynamicApiControllerBuilder将这些类与服务名信息传递给IApiControllerBuilder。
public void Build()
{
var types =
from
type in _assembly.GetTypes()
where
type.IsPublic && type.IsInterface && typeof(T).IsAssignableFrom(type) && IocManager.Instance.IsRegistered(type)
select
type; if (_typePredicate != null)
{
types = types.Where(t => _typePredicate(t));
} foreach (var type in types)
{
var serviceName = _serviceNameSelector != null
? _serviceNameSelector(type)
: GetConventionalServiceName(type); if (!string.IsNullOrWhiteSpace(_servicePrefix))
{
serviceName = _servicePrefix + "/" + serviceName;
} var builder = typeof(DynamicApiControllerBuilder)
.GetMethod("For", BindingFlags.Public | BindingFlags.Static)
.MakeGenericMethod(type)
.Invoke(null, new object[] { serviceName }); if (_filters != null)
{
builder.GetType()
.GetMethod("WithFilters", BindingFlags.Public | BindingFlags.Instance)
.Invoke(builder, new object[] { _filters });
} builder.GetType()
.GetMethod("Build", BindingFlags.Public | BindingFlags.Instance)
.Invoke(builder, new object[0]);
}
}
IApiControllerBuilder将通过服务类生成DynamicApiControllerInfo，再将IApiControllerBuilder存储于DynamicApiControllerManager中，同时分析服务类，将公开非静态方法作为action，存储到DynamicApiControllerManager.Actions
internal class ApiControllerBuilder<T> : IApiControllerBuilder<T>
{
/// <summary>
/// Name of the controller.
/// </summary>
private readonly string _serviceName; /// <summary>
/// List of all action builders for this controller.
/// </summary>
private readonly IDictionary<string, ApiControllerActionBuilder<T>> _actionBuilders; /// <summary>
/// Action Filters to apply to the whole Dynamic Controller.
/// </summary>
private IFilter[] _filters; /// <summary>
/// Creates a new instance of ApiControllerInfoBuilder.
/// </summary>
/// <param name="serviceName">Name of the controller</param>
public ApiControllerBuilder(string serviceName)
{
if (string.IsNullOrWhiteSpace(serviceName))
{
throw new ArgumentException("serviceName null or empty!", "serviceName");
} if (!DynamicApiServiceNameHelper.IsValidServiceName(serviceName))
{
throw new ArgumentException("serviceName is not properly formatted! It must contain a single-depth namespace at least! For example: 'myapplication/myservice'.", "serviceName");
} _serviceName = serviceName; _actionBuilders = new Dictionary<string, ApiControllerActionBuilder<T>>();
foreach (var methodInfo in DynamicApiControllerActionHelper.GetMethodsOfType(typeof(T)))
{
_actionBuilders[methodInfo.Name] = new ApiControllerActionBuilder<T>(this, methodInfo);
}
} /// <summary>
/// The adds Action filters for the whole Dynamic Controller
/// </summary>
/// <param name="filters"> The filters. </param>
/// <returns>The current Controller Builder </returns>
public IApiControllerBuilder<T> WithFilters(params IFilter[] filters)
{
_filters = filters;
return this;
} /// <summary>
/// Used to specify a method definition.
/// </summary>
/// <param name="methodName">Name of the method in proxied type</param>
/// <returns>Action builder</returns>
public IApiControllerActionBuilder<T> ForMethod(string methodName)
{
if (!_actionBuilders.ContainsKey(methodName))
{
throw new AbpException("There is no method with name " + methodName + " in type " + typeof(T).Name);
} return _actionBuilders[methodName];
} /// <summary>
/// Builds the controller.
/// This method must be called at last of the build operation.
/// </summary>
public void Build()
{
var controllerInfo = new DynamicApiControllerInfo(_serviceName, typeof(DynamicApiController<T>), _filters); foreach (var actionBuilder in _actionBuilders.Values)
{
if (actionBuilder.DontCreate)
{
continue;
} controllerInfo.Actions[actionBuilder.ActionName] = actionBuilder.BuildActionInfo();
} IocManager.Instance.IocContainer.Register(
Component.For<AbpDynamicApiControllerInterceptor<T>>().LifestyleTransient(),
Component.For<DynamicApiController<T>>().Proxy.AdditionalInterfaces(new[] { typeof(T) }).Interceptors<AbpDynamicApiControllerInterceptor<T>>().LifestyleTransient()
); DynamicApiControllerManager.Register(controllerInfo); LogHelper.Logger.DebugFormat("Dynamic web api controller is created for type '{0}' with service name '{1}'.", typeof(T).FullName, controllerInfo.ServiceName);
}
}