Webapi,webnet receiving JSONP

This essay is reproduced in the article, do not laugh

The first step:

Create Jsonpmediatypeformatter

  Public classJsonpmediatypeformatter:jsonmediatypeformatter { Public stringCallback {Get;Private Set; }  PublicJsonpmediatypeformatter (stringcallback =NULL)        {             This. Callback =callback; }         Public OverrideTask writetostreamasync (Type type,Objectvalue, Stream writestream, httpcontent content, TransportContext transportcontext) {            if(string. IsNullOrEmpty ( This. Callback)) {return Base.            Writetostreamasync (type, value, Writestream, content, TransportContext); }            Try            {                 This.                WriteToStream (type, value, writestream, content); returnTask.fromresult<asyncvoid> (Newasyncvoid ()); }            Catch(Exception Exception) {TaskCompletionSource<AsyncVoid> Source =NewTaskcompletionsource<asyncvoid>(); Source.                SetException (Exception); returnsource.            Task; }        }        Private voidWriteToStream (Type type,Objectvalue, Stream writestream, httpcontent content) {Jsonserializer Serializer= Jsonserializer.create ( This.            Serializersettings); using(StreamWriter StreamWriter =NewStreamWriter (Writestream, This. Supportedencodings.first ()))using(JsonTextWriter JsonTextWriter =NewJsonTextWriter (streamWriter) {closeoutput =false}) {Jsontextwriter.writeraw ( This. Callback +"("); Serializer.                Serialize (jsontextwriter, value); Jsontextwriter.writeraw (")"); }        }         Public Overridemediatypeformatter getperrequestformatterinstance (type type, httprequestmessage request, Mediatypeheadervalue MediaType) {if(Request. Method! =httpmethod.get) {return  This; }            stringcallback; if(Request. Getquerynamevaluepairs (). ToDictionary (pair =pair. Key, Pair= = Pair. Value). TryGetValue ("Callback", outcallback)) {                return NewJsonpmediatypeformatter (callback); }            return  This; } [StructLayout (LayoutKind.Sequential, Size=1)]        Private structasyncvoid {}}

Step Two:

Global.asax Add the following code

protected void Application_Start ()        {
　　　　　　　//Return JSON when used            GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear ();                         // To set the JSONP format serialization method            GlobalConfiguration.Configuration.Formatters.Insert (0, new   jsonpmediatypeformatter ());            Arearegistration.registerallareas ();            Globalconfiguration.configure (webapiconfig.register);            Filterconfig.registerglobalfilters (globalfilters.filters);            Routeconfig.registerroutes (routetable.routes);            Bundleconfig.registerbundles (bundletable.bundles);        }

Webapi,webnet receive JSONP