I am unable to convert JSON string to .net object in asp.net. I am sending JSON string from client to server using hidden field (by keeping the JSON object.Tostring() in hidden field and reading the hidden field value in code behind file)
I use the JavaScriptSerializer class of ASP.net to serialize my object and return it to the client side. How can I deserialize the string using JavaScript?
I have an web application solution in asp.net webforms with 3 projects named:
1) TestiModels where are custom classes.
2)TestiServices where are are asmx web services
3)TestiApp where are UI files like default.aspx. inside this project consume webservices
For two days I am getting this error at default.aspx file:
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
Line 70: u.gender = RadioButtonList1.SelectedValue; Line 71: u.photo_path = FullPath; Line 72: int retVal = service.InsertUser(u); Line 73: if (retVal == -1) Line 74:
I have DataReader that holds the results from a stored procedure caal. The results consist of two fields ...
UserID UserName
Normally I bind these results to an ASP.NET dropdownlist control ...
ddlUserList.DataSource = rdr // rdr is the DataReader ddlUserList.DataTextField = "UserName" ddlUserList.DataValueField = "UserID" ddlUserList.DataBind()
However I am now trying to accomplish the same thing using jQuery AJAX. What I am stuck on is how to manually convert the dataset held in the DataReader to JSON. How are multiples values separated? Does this look correct?
I realize there are libraries out there such as JSON.NET to handle the serialization but I am in the learning stage now and want to make sure I understand everything from the bottom up.
I've scenario where I want to insert data into database without post back. there are around 12 to 13 fields which i need to insert. I'm passing DTO from the client side which is actually Json object. Now the problem which i'm facing is how to convert that Json object which i got in webservice to the "class" (in my case class name is User) object.
[Code]....
In the above case AddNewUser method takes the object of User class. But i'm getting casting error. So how do I convert Json object to the "User" class object?
Is there an easy way to populate my C# Object with the JSON object passed via AJAX?
//This is the JSON Object passed to C# WEBMETHOD from the page using JSON.stringify {"user":{"name":"asdf","teamname":"b","email":"c","players":["1","2"]}} //C# WebMetod That receives the JSON Object [WebMethod] public static void SaveTeam(Object user) { } //C# Class that represents the object structure of JSON Object passed in to the WebMethod public class User { public string name { get; set; } public string teamname { get; set; } public string email { get; set; } public Array players { get; set; } }
From VB.net code behind when I am trying to deserialize it it's stating that
"Expecting state 'Element'.. Encountered 'Text' with name '', namespace ''."
Deserialization code snippet:
Dim serializer = New DataContractJsonSerializer(GetType(List(Of Employee))) Dim memoryStream = New MemoryStream() Dim s = msg.Content.ReadAsString() serializer.WriteObject(memoryStream, s) memoryStream.Position = 0.......
I am fetching data from MySql database.When i look at the object it looks like this:But when this object is converted to String then it appears like this:The Formatting of the object is gone..How can i get/show the original formatting that is fetched from the database..
I want to serialize an object to json, so I'm using [Code]....
[Code]....
This is fine, but I want to return different json datasets depending on the circumstances. Lets say I have this object (a simplified example):
[DataContract] class foo { [DataMember] int productId [DataMember] string productName double price; //not used in json.. yet }
Which will serialize to a json object containing the product name & Id, but what if I also need to be able to return a different json object (say, productId and price but not name)? Can this be done somehow in the same object using WCF/DataContracts and DataMembers? This will be sent in an ajax query containing a collection of objects and needs to fast, so just including every member in every type of json request whether it's needed or not isn't a good solution.
I have an object called MyObject that has several properties. MyList is a list of MyObject that I populate with a linq query and then I serialize MyList into json. I end up with something like this
List<MyObject> MyList = new List<MyObject>();
MyList = TheLinqQuery(TheParam);
var TheJson = new System.Web.Script.Serialization.JavaScriptSerializer();
string MyJson = TheJson.Serialize(MyList);
What I want to do is serialize only parts of MyObject. For instance, I might have Property1, Property2...Propertyn and I want MyJson to only include Property3, Property5 and Property8. I thought of a way to do this by creating a new object with only the properties I want and from there create a new list for the serialization.
I could use the DataContractJsonSerializer Class and have custom Classes defined. However, am not sure how keys like "$" would get converted to in .Net.
I have a json object collection of geo locations that I build in the server. Each of those objects has two properties: "marker" and "onClick". Marker is for storing a Google Maps marker object and the onClick stores the name of the function to be called when that marker is clicked on the map.When I'm pushing the location objects into an array using javascript in the client side, I create the markers and assign them to each location object within the array.
My problem is that when I bind the marker with the onClick property, the function won't be found in the DOM and get an error.Is there a way to declare a property in a json object for using it on an event binding?
My json response contains json with structure (eg. "[[[],[]]]") but no actual content.
AJAX code:
[Code]....
It definitely recognizes structure (if I change the xml nodes, it reflects in the []'s) but just isn't inserting any content. I tried prefixing the web method with "<ScriptMethod(ResponseFormat:=ResponseFormat.Json)>" but it made no difference.
I have a list of person objects which I want to send in response to a jquery' ajax request. I want to send the list into JSON format. The list is as follows -
List<Person> PersonList = new List<Person>(); Person Atiq = new Person("Atiq Hasan Mollah", 23, "Whassap Homie"); Person Sajib = new Person("Sajib Mamud", 24, "Chol kheye ashi"); PersonList.Add(Atiq); PersonList.Add(Sajib);
How can I convert the "PersonList" list into JSON ?
I've created a simple (or what I thought was simple!) search form using Razor, MVC3 and the webgrid from the web helpers. I enabled paging, used a great article I found here to get that working... or so I thought. Basically what happens is that when I click the page buttons at the bottom of the grid it does something that I didn't expect, and creates a JSON object, then the browser prompts me to try and save it, and not as I expected to refill the grid. I can't see what I'm doing wrong, and before I break my monitor by throwing it onto the railway line!
[Code]....
My jQuery code
[Code]....
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.Mvc; using MvcApplication1.Models; using System.Configuration; using System.Web.Helpers; namespace MvcApplication1.Controllers { public class SearchController : Controller { // // GET: /Search/ Entities t = new Entities(ConfigurationManager.ConnectionStrings["Entities"].ConnectionString); public ActionResult Details(int id) { Tender_Question q = (from x in t.Tender_Questions where x.Unique_ID_number == id select x).SingleOrDefault(); Customer c = (from cu in t.Customers where cu.CustomersID == q.Company select cu).SingleOrDefault(); ViewBag.Customers = c.CompanyName; Panel_type pan = (from pa in t.Panel_types where pa.ID == q.Panel_type select pa).SingleOrDefault(); ViewBag.Panel = pan.Panel_type1; return View(q); } [HttpGet] public ActionResult Edit(int id) { Tender_Question q = (from x in t.Tender_Questions where x.Unique_ID_number == id select x).SingleOrDefault(); List<Customer> c = (from cu in t.Customers select cu).ToList(); ViewBag.Customers = c; return View(q); } [HttpPost] public ActionResult Edit(Tender_Question model) { if (ModelState.IsValid) { Tender_Question q = (from x in t.Tender_Questions where x.Unique_ID_number == model.Unique_ID_number select x).SingleOrDefault(); q.Answer = model.Answer; q.Company = model.Company; q.Customer = model.Customer; q.Date = model.Date; q.Page_Question_Ref = model.Page_Question_Ref; q.Panel_type = model.Panel_type; q.Question = model.Question; q.Type_of_tender = model.Type_of_tender; //add update code t.SaveChanges(); return RedirectToAction("Index"); } else { return View(model); } } [HttpGet] public ActionResult Search(int? page) { if (page.HasValue) { return RedirectToAction("EfficientPaging", new { page = page }); } else { return View(); } } [HttpPost] public ActionResult Search(int? page, FormCollection collection) { TempData.Clear(); IEnumerable<Tender_Question> q = getSearch(collection); TempData.Add("Results", q); return View(q); } private IEnumerable<Tender_Question> getSearch(FormCollection collection) { string question; string answer; IEnumerable<Tender_Question> q = t.Tender_Questions; question = collection["Question"]; answer = collection["Answer"]; if (!string.IsNullOrEmpty(question)) { if (question.EndsWith(",")) { question = question.Substring(0, question.Length - 1); } if (question.Length > 0) { if (question.Contains(",")) { string[] questioned = question.Split(','); foreach (string s in questioned) { q = q.Where(m => m.Question.Contains(s)); } } else { q = q.Where(m => m.Question.Contains(question)); } } } if (!string.IsNullOrEmpty(answer)) { if (answer.EndsWith(",")) { answer = answer.Substring(0, answer.Length - 1); } if (answer.Length > 0) { if (answer.Contains(",")) { string[] answered = answer.Split(','); foreach (string s in answered) { q = q.Where(m => m.Answer.Contains(s)); } } else { q = q.Where(m => m.Answer.Contains(answer)); } } } return q; } [HttpGet] public ActionResult EfficientPaging(int? page) { IEnumerable<Tender_Question> q = (IEnumerable<Tender_Question>)TempData["Results"]; int skip = page.HasValue ? page.Value - 1 : 0; q = q.OrderBy(o => o.Unique_ID_number).Skip(skip * 10).Take(10).ToList(); var grid = new WebGrid(q); var column = new WebGridColumn(); column.CanSort = false; column.ColumnName = "Unique_ID_number"; column.Header = "Edit"; column.Format = (item) => { return new HtmlString("<a href="/Home/Edit/" + column.ColumnName + "">Edit</a> "); }; var detcolumn = new WebGridColumn(); detcolumn.CanSort = false; detcolumn.ColumnName = "Unique_ID_number"; detcolumn.Header = "Details"; detcolumn.Format = (item) => { return new HtmlString("<a href="/Home/Details/" + column.ColumnName + "">Details</a> "); }; var htmlString = grid.GetHtml(htmlAttributes: new { id = "DataTable" }, columns: grid.Columns( column, detcolumn, grid.Column("Question"), grid.Column("Answer"), grid.Column("Company"), grid.Column(columnName: "Type_of_tender", header: "Type of Tender"), grid.Column(columnName: "Panel_type", header: "Panel type"), grid.Column(columnName: "Page_Question_Ref", header: "Page Question Ref"), grid.Column("Date") )); return Json(new { Data = htmlString.ToHtmlString(), Count =q.Count() / 10 }, JsonRequestBehavior.AllowGet); } } }
public class AccessToken { public string access_token {get;set;} public DateTime expires { get; set; } } public class TokenReturn { public List<AccessToken> tokens { get; set; } } JavaScriptSerializer ser = new JavaScriptSerializer(); TokenReturn result = ser.Deserialize<TokenReturn>(responseFromServer);
