JSON Data cannot be matched to web service signature

Question

I still can’t seem to get this to work.I’ve tried string arrays object arrays dictionaries. I might be formatting my JSON incorrectly however I am using the labs_JSON plugin. If I remove my data and test the webservice it calls correctly. The : My code looks as follows :

HTML :

<div style="display: block; float: left;">
        <asp:Repeater ID="rptMenuRecipeCategories" runat="server">
            <HeaderTemplate>
                <div class="recipeChecklistHeader">Menu Recipe Categories</div>
                <ul id="menuRecipeCategories" class="connectedSortable">
            </HeaderTemplate>
            <ItemTemplate>
                <li id="item_<%# Container.ItemIndex + 1 %>" recipeCategoryId='<%# Eval("RecipeCategoryID") %>' >
                    <%# Eval("RecipeCategory") %>
                </li>
            </ItemTemplate>
            <FooterTemplate>
                </ul>
            </FooterTemplate>
        </asp:Repeater>
</div>
<div style="display: block; float: left">
        <asp:Repeater ID="rptAvailableMenuRecipeCategories" runat="server">
            <HeaderTemplate>
                <div class="recipeChecklistHeader">Available Menu Recipes</div>
                <ul id="availabeMenuRecipeCategories" class="connectedSortable">
            </HeaderTemplate>
            <ItemTemplate>
                <li id="item_<%# Container.ItemIndex + 1 %>" recipeCategoryId='<%# Eval("RecipeCategoryID") %>'>
                    <%# Eval("RecipeCategory") %>
                </li>
            </ItemTemplate>
            <FooterTemplate>
                </ul>
            </FooterTemplate>
        </asp:Repeater>
</div>

JS:

    $(function () {
        $("#menuRecipeCategories, #availabeMenuRecipeCategories").sortable({
            connectWith: '.connectedSortable',
            update: function (ev, ui) {
                //var result = $('#menuRecipeCategories').sortable('toArray');
                //updateSequenceNumber(result);
            }
        }).disableSelection();
    });

//This is currently raised through a button click event function persistRecipeCategoriesToJSON() { var items = $('#menuRecipeCategories').sortable('toArray'); var dictionaryData = ''; var index = 0; var itemArray = new Array();

        for (i = 0; i <= items.length - 1; i++) {
            if (items[i].length == 0)
                continue;

            var item = $('#' + items[i])[0];
            var recipeCategoryId = item.attributes["recipeCategoryId"].nodeValue;
            itemArray[i] = recipeCategoryId;
        }

        persistPositionUsingAjax($.json.encode(itemArray));
    }

    $(document).ready(function () {
        $.ajaxSetup({
            type: "POST",
            contentType: "application/json; charset=utf-8",
            dataType: "json"
        });
    });

    function persistPositionUsingAjax(jsonData) {
        var webServiceURL = '<%=ResolveUrl("~/UserControls/MenuRecipeChecklistService.asmx")%>' + '/UpdateMenuRecipeChecklist';
        $.ajax({
            // This is page.name/MethodName     
            url: webServiceURL,

            // This is the data (method arguments)
            data: jsonData,

            // This is the handler for success.     
            success: function (msg) {
                alert('success');
            }
        });
    }  

JSON :

["1","2"]

Webservice:

[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public string UpdateMenuRecipeChecklist(*INPUT TYPE TO GO HERE*)
        {
            return "";
       }

**Ok guys. I've resolved this issue. It seemed The JSON was being formatted incorrectly with the Json labs plugin. I added this line to my persistRecipeCategoriesToJSON function:

var args = { jsonData: itemArray };
persistPositionUsingAjax($.json.encode(args));

The JSON is then formatted correctly by assigning a name to the object. I then I update the method signature of my webservice to:

public string UpdateMenuRecipeChecklist(string[] jsonData)

and everything then works :) . Thanks to everyone who attempted to help!

Answer 1

Try this for your web method signature:

[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public string UpdateMenuRecipeChecklist(List<string>)
{ 
   return ""; 
}

EDIT: Have modified to have the parameter as a List of string now, rather than IEnumerable of string.

Also why don't you try passing the object itself and not the encoded string.

Like:

persistPositionUsingAjax(itemArray)

Answer 2

Hi guys. This question is now resolved. I've modified the original article to contain the solution at the bottom.