How to send response using Json object - vb.net

I am working on a project in which a server page is called through XMLHttp and now I want to retrieve response the called page in json object.
and I never used json so I don't have any idea about it so please tell me how I can make json object in my server side vb.net page.

You can use JSON.NET or use DataContractJsonSerializer built in .NET 3.5.

It isn't too clear what you need to do, as far as I can understand you want to send to the caller JSON responses from a webserver, using VB.NET. I suggest to take a look at JSON.NET project, which makes serializing and deserializing your .NET objects to JSON a breeze!

Related

asp.net web api having trouble sending objects

I've just switched to using the new web api for MVC 4, and I am having great difficulty in deserializing the response from my webservice.
This is my server code:
IEnumerable<Fish> myList = GetFish();
return Request.CreateResponse(HttpStatusCode.OK, myList,"application/xml");
This is serialised as:
<ArrayOfFish xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns=\"http://schemas.datacontract.org/2004/07/MySolution.NameSpace.Resources\" />
As there are no results returned.
When I try to parse this using the XmlMediaTypeFormatter, I get an error saying it wasn't expecting what it got.
My code to deserialise it hasn't changed from before I started using web api, and is simply:
return content.ReadAsAsync<T>(formatters).Result;
formatters is a List of formatters, containing only the XmlMediaTypeFormatter
T is a generic list of Fish
If I omit the "application/xml" type then it appears to send in JSon (as the result is []) however the client expects xml, and will not use a JSon serialiser on it for some reason, even if I explicitly put the type as text/json.
It should be fairly simple to deserialise objects as it's exactly what I was doing before, I've just changed my server very slightly to use CreateResponse to make a HttpResponseMessage instead of using HttpResponseMessage<T> directly, because the generic version isn't supported anymore. I can't find a single client/server example online of someone decoding the result into objects which is frustrating.
Any ideas?
An XmlSerializer can't serialize an interface (IEnumerable). Convert to a List before returning.
return Request.CreateResponse(HttpStatusCode.OK, myList.ToList(),"application/xml");
simlar question with references here - XmlSerializer won't serialize IEnumerable
I ended up discovering that the serialization method web api uses is very slightly different to the former, standard way. I added this to my global.asax and it resolved the issue:
GlobalConfiguration.Configuration.Formatters.Insert(0, new XmlMediaTypeFormatter() { UseXmlSerializer = true });

Dynamically create json using WCF service to feed MTDialog application

I wish to create a MonoTouch MTDialog-based app that upon launching adds a single element to the MonoTouch Dialog and then render the screen. This single element will be a JsonElement similar to this -
var je = new JsonElement ("Dynamic Data", "http://tirania.org/tmp/demo.json");
as shown in the sample application. However, instead of referencing a pre-built json file on a server, I wish to have the url point at a WCF OData service which will dynamically build the json data.
I am not sure what is the easiest way to do this. I am a bit lost after reading over the documentation. Is there some library I can include in my server-side C# app which I can then use to build out the elements and return as a json string of information?
I already have a WCF application up and running and just need to add an entry point which will call the method to create some simple json data for MonoTouch dialog to consume.
Any examples or suggestions are greatly appreciated as I am trying to get a simple solution completed by this weekend.
You're looking for a C# JSON library? How about JSON.NET http://james.newtonking.com/pages/json-net.aspx
You might also look at ServiceStack.NET -- they have a MonoTouch client.

How to extract/convert values from JSON response to a VB.NET Object and vice versa?

I'm getting a JSON response after accessing a web service with my window application written in VB.NET. How can I convert the JSON response to a VB.NET object and vice versa? Any help will be appreciated! Thanks!
You may want to take a look at PW.JSON. As far as I know, it is the only library to serialize / deserialize JSON objects in VB.net. JSON.org lists a number of different libraries for JSON serialization at the bottom of the page, but unfortunately, PW.JSON appears to be the only one for VB.net.

Retrieve generic list in JSON format on client side

I send generic list of data by wcf service using REST. I understand that on server side it was serializing, and on client side deserializing. How can I get data before deserialization in JSON format to show it to user ?
Take a look at this page, and drop the automatic (de)serialization.
I use DownloadData method from WebClient class to invoke RESTful service and returned data was converted to string using Encoding class :)

In WCF, how do I convert a Datatable to a format that will output in JSON store format without classes

So here's the problem - I have a DataTable I want WCF (.NET 3.5) to send out in a JSON store format commonly used in ExtJS, etc - basically "Rows[{"Field1":value,"Field2":value},{...}]" but I cannot find the right structure to feed back to the Operation contract to send it out in this format.
So any ideas, or any further info needed.
Thanks, in advance!
AndyPC, unfortunately, you're out of luck.
If you're dealing with an object whose type is an IXmlSerializable, the WCF JSON serializer delegates to IXmlSerializable methods first, gets the serialized XML out of them, wraps the XML in a JSON string, and just passes that on. This is one of the major weaknesses of the WCF JSON model in .NET 3.5. I think the entity framework (WCF Data Services) technologies try to handle this more elegantly, but not sure. I'd recommend manually using the JSON serializer and crafting up a string or a manual serialization mechanism that does what you want...