基于 WebAPI 的 API 实现

本文基于

• WebAPI
• OData （微软发起的一个格式标准，其中一个比较有意思的是可以直接在 Excel 中填入 API 就可以展示了）
• Swashbuckle.OData（把 API 生成一个测试页面）

项目结构

代码

• SwaggerConfig

 [assembly: PreApplicationStartMethod(typeof(SwaggerConfig), "Register")]

 namespace ODataWebAPI
 {
     /// <summary>
     /// SwaggerConfig
     /// </summary>
     public class SwaggerConfig
     {
         /// <summary>
         /// SwaggerConfig Register
         /// </summary>
         public static void Register()
         {
             GlobalConfiguration.Configuration.EnableSwagger(c =>
             {
                 // By default, the service root url is inferred from the request used to access the docs.
                 // However, there may be situations (e.g. proxy and load-balanced environments) where this does not
                 // resolve correctly. You can workaround this by providing your own code to determine the root URL.
                 //
                 //c.RootUrl(req => GetRootUrlFromAppConfig());

                 // If schemes are not explicitly provided in a Swagger 2.0 document, then the scheme used to access
                 // the docs is taken as the default. If your API supports multiple schemes and you want to be explicit
                 // about them, you can use the "Schemes" option as shown below.
                 //
                 //c.Schemes(new[] { "http", "https" });

                 // Use "SingleApiVersion" to describe a single version API. Swagger 2.0 includes an "Info" object to
                 // hold additional metadata for an API. Version and title are required but you can also provide
                 // additional fields by chaining methods off SingleApiVersion.
                 //
                 c.SingleApiVersion("v1", "Sample API for Swashbuckle.OData")
                     .Contact(contactBuilder => contactBuilder
                     .Url("http://localhost:53515/swagger/ui/index#/"));

                 // If your API has multiple versions, use "MultipleApiVersions" instead of "SingleApiVersion".
                 // In this case, you must provide a lambda that tells Swashbuckle which actions should be
                 // included in the docs for a given API version. Like "SingleApiVersion", each call to "Version"
                 // returns an "Info" builder so you can provide additional metadata per API version.
                 //
                 //c.MultipleApiVersions(
                 //    (apiDesc, targetApiVersion) => ResolveVersionSupportByRouteConstraint(apiDesc, targetApiVersion),
                 //    (vc) =>
                 //    {
                 //        vc.Version("v2", "Swashbuckle Dummy API V2");
                 //        vc.Version("v1", "Swashbuckle Dummy API V1");
                 //    });

                 // You can use "BasicAuth", "ApiKey" or "OAuth2" options to describe security schemes for the API.
                 // See https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md for more details.
                 // NOTE: These only define the schemes and need to be coupled with a corresponding "security" property
                 // at the document or operation level to indicate which schemes are required for an operation. To do this,
                 // you'll need to implement a custom IDocumentFilter and/or IOperationFilter to set these properties
                 // according to your specific authorization implementation
                 //
                 //c.BasicAuth("basic")
                 //    .Description("Basic HTTP Authentication");
                 //
                 //c.ApiKey("apiKey")
                 //    .Description("API Key Authentication")
                 //    .Name("apiKey")
                 //    .In("header");
                 //
                 //c.OAuth2("oauth2")
                 //    .Description("OAuth2 Implicit Grant")
                 //    .Flow("implicit")
                 //    .AuthorizationUrl("http://petstore.swagger.wordnik.com/api/oauth/dialog")
                 //    //.TokenUrl("https://tempuri.org/token")
                 //    .Scopes(scopes =>
                 //    {
                 //        scopes.Add("read", "Read access to protected resources");
                 //        scopes.Add("write", "Write access to protected resources");
                 //    });

                 // Set this flag to omit descriptions for any actions decorated with the Obsolete attribute
                 //c.IgnoreObsoleteActions();

                 // Each operation be assigned one or more tags which are then used by consumers for various reasons.
                 // For example, the swagger-ui groups operations according to the first tag of each operation.
                 // By default, this will be controller name but you can use the "GroupActionsBy" option to
                 // override with any value.
                 //
                 //c.GroupActionsBy(apiDesc => apiDesc.HttpMethod.ToString());

                 // You can also specify a custom sort order for groups (as defined by "GroupActionsBy") to dictate
                 // the order in which operations are listed. For example, if the default grouping is in place
                 // (controller name) and you specify a descending alphabetic sort order, then actions from a
                 // ProductsController will be listed before those from a CustomersController. This is typically
                 // used to customize the order of groupings in the swagger-ui.
                 //
                 //c.OrderActionGroupsBy(new DescendingAlphabeticComparer());

                 // If you annotate Controllers and API Types with
                 // Xml comments (http://msdn.microsoft.com/en-us/library/b2s063f7(v=vs.110).aspx), you can incorporate
                 // those comments into the generated docs and UI. You can enable this by providing the path to one or
                 // more Xml comment files.
                 //
                 var baseDirectory = AppDomain.CurrentDomain.BaseDirectory;
                 var commentsFileName = Assembly.GetExecutingAssembly().GetName().Name + ".XML";
                 var commentsFile = Path.Combine(baseDirectory, "App_Data", commentsFileName);
                 c.IncludeXmlComments(commentsFile);

                 // Swashbuckle makes a best attempt at generating Swagger compliant JSON schemas for the various types
                 // exposed in your API. However, there may be occasions when more control of the output is needed.
                 // This is supported through the "MapType" and "SchemaFilter" options:
                 //
                 // Use the "MapType" option to override the Schema generation for a specific type.
                 // It should be noted that the resulting Schema will be placed "inline" for any applicable Operations.
                 // While Swagger 2.0 supports inline definitions for "all" Schema types, the swagger-ui tool does not.
                 // It expects "complex" Schemas to be defined separately and referenced. For this reason, you should only
                 // use the "MapType" option when the resulting Schema is a primitive or array type. If you need to alter a
                 // complex Schema, use a Schema filter.
                 //
                 //c.MapType<ProductType>(() => new Schema { type = "integer", format = "int32" });
                 //
                 // If you want to post-modify "complex" Schemas once they've been generated, across the board or for a
                 // specific type, you can wire up one or more Schema filters.
                 //
                 //c.SchemaFilter<ApplySchemaVendorExtensions>();

                 // Set this flag to omit schema property descriptions for any type properties decorated with the
                 // Obsolete attribute
                 //c.IgnoreObsoleteProperties();

                 // In a Swagger 2.0 document, complex types are typically declared globally and referenced by unique
                 // Schema Id. By default, Swashbuckle does NOT use the full type name in Schema Ids. In most cases, this
                 // works well because it prevents the "implementation detail" of type namespaces from leaking into your
                 // Swagger docs and UI. However, if you have multiple types in your API with the same class name, you'll
                 // need to opt out of this behavior to avoid Schema Id conflicts.
                 //
                 //c.UseFullTypeNameInSchemaIds();

                 // In accordance with the built in JsonSerializer, Swashbuckle will, by default, describe enums as integers.
                 // You can change the serializer behavior by configuring the StringToEnumConverter globally or for a given
                 // enum type. Swashbuckle will honor this change out-of-the-box. However, if you use a different
                 // approach to serialize enums as strings, you can also force Swashbuckle to describe them as strings.
                 //
                 //c.DescribeAllEnumsAsStrings();

                 // Similar to Schema filters, Swashbuckle also supports Operation and Document filters:
                 //
                 // Post-modify Operation descriptions once they've been generated by wiring up one or more
                 // Operation filters.
                 //
                 //c.OperationFilter<AddDefaultResponse>();
                 //
                 // If you've defined an OAuth2 flow as described above, you could use a custom filter
                 // to inspect some attribute on each action and infer which (if any) OAuth2 scopes are required
                 // to execute the operation
                 //
                 //c.OperationFilter<AssignOAuth2SecurityRequirements>();

                 // Post-modify the entire Swagger document by wiring up one or more Document filters.
                 // This gives full control to modify the final SwaggerDocument. You should have a good understanding of
                 // the Swagger 2.0 spec. - https://github.com/swagger-api/swagger-spec/blob/master/versions/2.0.md
                 // before using this option.
                 //
                 c.DocumentFilter<ApplyResourceDocumentation>();

                 // In contrast to WebApi, Swagger 2.0 does not include the query string component when mapping a URL
                 // to an action. As a result, Swashbuckle will raise an exception if it encounters multiple actions
                 // with the same path (sans query string) and HTTP method. You can workaround this by providing a
                 // custom strategy to pick a winner or merge the descriptions for the purposes of the Swagger docs
                 //
                 //c.ResolveConflictingActions(apiDescriptions => apiDescriptions.First());

                 // Wrap the default SwaggerGenerator with additional behavior (e.g. caching) or provide an
                 // alternative implementation for ISwaggerProvider with the CustomProvider option.
                 //
                 c.CustomProvider(defaultProvider => new ODataSwaggerProvider(defaultProvider, c).Configure(odataConfig =>
                 {
                     // Set this flag to include navigation properties in your entity swagger models
                     //
                     //odataConfig.IncludeNavigationProperties();
                 }));
             })
                 .EnableSwaggerUi(c =>
                 {
                     // Use the "InjectStylesheet" option to enrich the UI with one or more additional CSS stylesheets.
                     // The file must be included in your project as an "Embedded Resource", and then the resource's
                     // "Logical Name" is passed to the method as shown below.
                     //
                     //c.InjectStylesheet(containingAssembly, "Swashbuckle.Dummy.SwaggerExtensions.testStyles1.css");

                     // Use the "InjectJavaScript" option to invoke one or more custom JavaScripts after the swagger-ui
                     // has loaded. The file must be included in your project as an "Embedded Resource", and then the resource's
                     // "Logical Name" is passed to the method as shown above.
                     //
                     //c.InjectJavaScript(thisAssembly, "Swashbuckle.Dummy.SwaggerExtensions.testScript1.js");

                     // The swagger-ui renders boolean data types as a dropdown. By default, it provides "true" and "false"
                     // strings as the possible choices. You can use this option to change these to something else,
                     // for example 0 and 1.
                     //
                     //c.BooleanValues(new[] { "0", "1" });

                     // By default, swagger-ui will validate specs against swagger.io's online validator and display the result
                     // in a badge at the bottom of the page. Use these options to set a different validator URL or to disable the
                     // feature entirely.
                     //c.SetValidatorUrl("http://localhost/validator");
                     //c.DisableValidator();

                     // Use this option to control how the Operation listing is displayed.
                     // It can be set to "None" (default), "List" (shows operations for each resource),
                     // or "Full" (fully expanded: shows operations and their details).
                     //
                     //c.DocExpansion(DocExpansion.List);

                     // Use the CustomAsset option to provide your own version of assets used in the swagger-ui.
                     // It's typically used to instruct Swashbuckle to return your version instead of the default
                     // when a request is made for "index.html". As with all custom content, the file must be included
                     // in your project as an "Embedded Resource", and then the resource's "Logical Name" is passed to
                     // the method as shown below.
                     //
                     //c.CustomAsset("index", containingAssembly, "YourWebApiProject.SwaggerExtensions.index.html");

                     // If your API has multiple versions and you've applied the MultipleApiVersions setting
                     // as described above, you can also enable a select box in the swagger-ui, that displays
                     // a discovery URL for each version. This provides a convenient way for users to browse documentation
                     // for different API versions.
                     //
                     //c.EnableDiscoveryUrlSelector();

                     // If your API supports the OAuth2 Implicit flow, and you've described it correctly, according to
                     // the Swagger 2.0 specification, you can enable UI support as shown below.
                     //
                     //c.EnableOAuth2Support("test-client-id", "test-realm", "Swagger UI");
                 });
         }
     }
 }

• WebApiConfig

 public static class WebApiConfig
     {
         /// <summary>
         /// WebApiConfig Register
         /// </summary>
         /// <param name="config"></param>
         public static void Register(HttpConfiguration config)
         {
             ODataModelBuilder builder = new ODataConventionModelBuilder();
             builder.EntitySet<UserModel>("Users");
             config.MapODataServiceRoute(
                 routeName: "ODataRoute",
                 routePrefix: null,
                 model: builder.GetEdmModel());
         }
     }

• UsersController

 public class UsersController : ODataController
     {
         /// <summary>
         /// 查询用户
         /// </summary>
         /// <returns></returns>
         [EnableQuery]
         public List<UserModel> Get()
         {
             return new List<UserModel>()
             {
                 new UserModel { Id = , Name = "Zhang San" },
                 new UserModel { Id = , Name = "Li Si" }
             };
         }
     }

• AesourceDocumentation

 public class ApplyResourceDocumentation : IDocumentFilter
     {
         /// <summary>
         /// Apply
         /// </summary>
         /// <param name="swaggerDoc"></param>
         /// <param name="schemaRegistry"></param>
         /// <param name="apiExplorer"></param>
         public void Apply(SwaggerDocument swaggerDoc, SchemaRegistry schemaRegistry, IApiExplorer apiExplorer)
         {
             swaggerDoc.tags = new List<Tag>
             {
                 new Tag { name = "Users", description = "a RESTier resource" }
             };
         }
     }

• UserModelMap

 public class UserModelMap : EntityTypeConfiguration<UserModel>
     {
         /// <summary>
         /// UserModelMap
         /// </summary>
         public UserModelMap()
         {
             //this.ToTable("dbo.User");
             this.HasKey(u => u.Id);

             this.Property(u => u.Name).IsRequired();
         }
     }

• UserModel

 public class UserModel
     {
         /// <summary>
         /// User Id
         /// </summary>
         public int Id { get; set; }
         /// <summary>
         /// User Name
         /// </summary>
         public string Name { get; set; }
     }

• EfContext

 public class EfContext : DbContext
     {
         /// <summary>
         /// Users
         /// </summary>
         public DbSet<UserModel> Users { get; set; }

         /// <summary>
         /// EfContext ctor
         /// </summary>
         public EfContext()
             : base("name=EfContext")
         {
         }

         /// <summary>
         /// This method is called when the model for a derived context has been initialized, but
         ///             before the model has been locked down and used to initialize the context.  The default
         ///             implementation of this method does nothing, but it can be overridden in a derived class
         ///             such that the model can be further configured before it is locked down.
         /// </summary>
         /// <remarks>
         /// Typically, this method is called only once when the first instance of a derived context
         ///             is created.  The model for that context is then cached and is for all further instances of
         ///             the context in the app domain.  This caching can be disabled by setting the ModelCaching
         ///             property on the given ModelBuidler, but note that this can seriously degrade performance.
         ///             More control over caching is provided through use of the DbModelBuilder and DbContextFactory
         ///             classes directly.
         /// </remarks>
         /// <param name="modelBuilder">The builder that defines the model for the context being created. </param>
         protected override void OnModelCreating(DbModelBuilder modelBuilder)
         {
             base.OnModelCreating(modelBuilder);

             modelBuilder.Configurations.Add(new UserModelMap());
         }
     }

Tips：

• 53515 是项目设置 Web 选项里的端口号，具体请查询真实的端口号
• 勾选项目设置 Build 选项里的XML documentation file，因为 Swagger 会用 xml 里的注释作为说明，请把代码中的 /// 注释补全，这样才能生成说明

运行结果

由于测试直接返回的固定数据，所以，当运行后就可以通过 API 得到结果了，并且可以通过 Swagger 测试页面看到 API 的信息，并可以测试。

此例中的 API 为

http://localhost:53515/Users?$orderby=Id desc  （请求的 API）

http://localhost:53515/swagger/ui/index#/  (Swagger 生成的测试页面)