asp.net-web-api - 自托管ASPNET WebAPI中的MediaTypeFormatter问题

我在SelfHosted AspNet WebAPI中实现了自定义MediaTypeFormatter。我使用Unity.WebApi进行依赖性解析。控制器类只知道模型类实现的接口，而存储库则根据操作给出具体的模型。

自定义MediaTypeFormatter继承自BufferedMediaTypeFormatter，如下所述：http://www.asp.net/web-api/overview/formats-and-model-binding/media-formatters。

问题是此媒体类型格式化程序无法正常工作。即使我用来调试代码，也永远不会遇到ReadFormStream方法。有人知道吗：

可能出现什么问题？
我是否需要告诉unity容器将接口映射到模型类？
如何在自定义媒体类型格式化程序中获取对依赖项解析程序的引用？

以下是添加格式化程序的代码：


var config = new SelfHostConfiguration("https://xxx.xxx.xxx.xxx:xxxx/");
config.Formatters.Add(new EntityTypeFormatter());

以下是EntityController的代码：

    public class EntityController : ApiController
    {
        private readonly IEntitiesRepository repository = null;

        public EntityController(IEntitiesRepository repository)
        {
            if (repository == null)
            {
                throw new ArgumentNullException("repository");
            }

            this.repository = repository;
        }

        public IEnumerable<IEntity> Get()
        {
            return (IEnumerable<IEntity>)repository.Get();
        }
    }

以下是EntityRepository的代码：

    public class EntitiesRepository : IEntitiesRepository
    {
        public IEnumerable<IEntity> Get()
        {
            return new Entities[]
            {
                new Entity
                { 
                    Prop1 = "value for property 1",
                    Prop2 = "value for property 2",
                    Prop3 = "value for property 3"
                },
                new Entity
                { 
                    Prop1 = "value for property 1",
                    Prop2 = "value for property 2",
                    Prop3 = "value for property 3"
                }
            };
        }
        public IEntity Get(long id)
        {
            return new Entity
                {
                    Prop1 = Convert.ToString(id),
                    Prop2 = "value for property 2",
                    Prop3 = "value for property 3"
                };
        }
    }

以下是EntityMediaTypeFormatter类的实现：

public class EntityMediaTypeFormatter : BufferedMediaTypeFormatter 
    {
        public EntityMediaTypeFormatter()
            : base()
        {
            SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/xml"));
            SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
        }

        public override bool CanReadType(Type type)
        {
            if (type == null)
            {
                throw new ArgumentNullException("type");
            }

            if (type is IEntity)
            {
                return true;
            }
            else if (type.IsGenericType)
            {
                return type.GenericTypeArguments.Single(a => a.GetType().Equals(typeof(IEntity))) != null;
            }

            return false;
        }
        public override bool CanWriteType(Type type)
        {
            if (type == null)
            {
                throw new ArgumentNullException("type");
            }

            if (type is IEntity)
            {
                return true;
            }

            return false;
        }

        public override object ReadFromStream(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger)
        {
            if (type.IsInterface)
            {
                type = GetConcreteType(type);
            }

            return base.ReadFromStream(type, readStream, content, formatterLogger);
        }
        public override void WriteToStream(Type type, object value, Stream writeStream, HttpContent content)
        {
            //nothing special for now...
            base.WriteToStream(type, value, writeStream, content);
        }

        private Type GetConcreteType(Type type)
        {
            //TODO: Need to find a way to DependencyResolver to get the concrete type
            return typeof(Entity);
        }
    }

提前感谢任何帮助。

自托管ASPNET WebAPI中的MediaTypeFormatter问题

1 个答案: