Webapi Learning Note 07: Using the Webapi core file template--Creating an OData endpoint

1.Web Project

1.1 Overview

The EF access and operations database described above is out (of course not), and this chapter uses OData (open source data protocol) ...

1.2 Creating a Project

In Solution Explorer, right-click Add-New Solution folder named: OData

Right-click the "OData" Logical folder, add-"New project:

1.3 Installing the OData framework

1.4 Adding a model

Under the Models folder, add Product.cs, whose code:

namespaceproductservice.models{ Public classProduct { Public intId {Get;Set; }  Public stringName {Get;Set; }  Public decimalPrice {Get;Set; }  Public stringCategory {Get;Set; } }}

1.5 Installing EF

1.6 Adding a Context class

Under the Models folder, add EFContext.cs, whose code:

using System.Data.Entity; namespace productservice.models{    publicclass  efcontext:dbcontext    {          public efcontext ()            base("name=productcontext"         {        }        publicgetset;}}    }

1.7 Connection string

Under <configuration> in Web. config, add:

  <connectionStrings>    <add name="productcontext" connectionstring="          Initial catalog=productdb; Integrated security=true; multipleactiveresultsets=True;         AttachDbFileName=| datadirectory| Productdb.mdf"      providername="System.Data.SqlClient "/>  </connectionStrings>

1.8 Configuring Endpoints
Modify the App_start\webapiconfig.cs, its code:

usingProductservice.models;usingSystem.Web.Http;usingSystem.Web.OData.Builder;usingSystem.Web.OData.Extensions;namespaceproductservice{ Public Static classWebapiconfig { Public Static voidRegister (httpconfiguration config) {//Web API Configuration and Services//Create an Entity Data Model (EDM)Odatamodelbuilder Builder =NewOdataconventionmodelbuilder (); Builder. EntitySet<Product> (" Products"); //Add RouteCONFIG. Mapodataserviceroute (routeName:"Odataroute", Routeprefix:NULL, Model:builder.            Getedmmodel ()); //Web API Routing//CONFIG.            Maphttpattributeroutes (); //CONFIG. Routes.maphttproute (//Name: "Defaultapi",//routetemplate: "Api/{controller}/{id}",//defaults:new {id = routeparameter.optional}//);        }    }}

1.9 Adding a Controller
Under the Controllers folder, add ProductsController.cs, whose code:

usingProductservice.models;usingSystem.Data.Entity;usingSystem.Data.Entity.Infrastructure;usingSystem.Linq;usingSystem.Net;usingSystem.Threading.Tasks;usingSystem.Web.Http;usingSystem.Web.OData;namespaceproductservice.controllers{ Public classProductscontroller:odatacontroller {Efcontext db =NewEfcontext (); [Enablequery] PublicIqueryable<product>Get () {returndb.        Products; } [Enablequery] PublicSingleresult<product> Get ([Fromodatauri]intkey) {IQueryable<Product> result = db. Products.where (p = p.id = =key); returnsingleresult.create (Result); }         Public AsyncTask<ihttpactionresult>Post (product product) {if(!modelstate.isvalid) {returnbadrequest (modelstate); } db.            Products.add (product); awaitdb.            Savechangesasync (); returnCreated (product); }         Public AsyncTask<ihttpactionresult> Patch ([Fromodatauri]intKey, delta<product>product) {            if(!modelstate.isvalid) {returnbadrequest (modelstate); }            varentity =awaitdb.            Products.findasync (key); if(Entity = =NULL)            {                returnNotFound (); } product.            Patch (entity); Try            {                awaitdb.            Savechangesasync (); }            Catch(dbupdateconcurrencyexception) {if(!productexists (Key)) {                    returnNotFound (); }                Else                {                    Throw; }            }            returnUpdated (entity); }         Public AsyncTask<ihttpactionresult> Put ([Fromodatauri]intkey, Product update) {            if(!modelstate.isvalid) {returnbadrequest (modelstate); }            if(Key! =Update. Id) {returnbadrequest (); } db. Entry (update). State=entitystate.modified; Try            {                awaitdb.            Savechangesasync (); }            Catch(dbupdateconcurrencyexception) {if(!productexists (Key)) {                    returnNotFound (); }                Else                {                    Throw; }            }            returnUpdated (update); }         Public AsyncTask<ihttpactionresult> Delete ([Fromodatauri]intkey) {            varProduct =awaitdb.            Products.findasync (key); if(Product = =NULL)            {                returnNotFound (); } db.            Products.remove (product); awaitdb.            Savechangesasync (); returnStatusCode (httpstatuscode.nocontent); }        Private BOOLProductexists (intkey) {            returnDb. Products.any (p = p.id = =key); }        protected Override voidDispose (BOOLdisposing) {db.            Dispose (); Base.        Dispose (disposing); }    }}

1.10 Run

Webapi Learning Note 07: Using the Webapi core file template--Creating an OData endpoint