将JSON对象发布到Web方法 - $ .ajax

Question

I'm trying to get data from a form on a button click and send it to a web method in my code behind. I'd like to pass it as a JSON object or at least I think that's the convention? Here's my current code however it generates an error (Shown below the code).

$("#addTask")
    .click(function( event ) {
    var newTask = new Object();
        newTask.TaskName = $('#ctl00_ContentArea_taskName').val();
        newTask.TaskDescription = $('#ctl00_ContentArea_taskDescription').val();
        newTask.SQLObjectID = $('#ctl00_ContentArea_sqlReportingID').val();
        newTask.WarehouseSQLObjectID = $('#ctl00_ContentArea_warehouseSQLObjectID').val();

        $.ajax({
           type: "POST",
           url: 'AddTask.aspx/validateTask',
           data: JSON.stringify(newTask),
           contentType: "application/json; charset=utf-8",
           dataType: "json",
           async: false,
           success : function(data) { 
                alert( data.d ); 
           }
        });  
    });

__

{"Message":"Invalid web service call, missing value for parameter: \u0027newTask\u0027.","StackTrace":"   at System.Web.Script.Services.WebServiceMethodData.CallMethod(Object target, IDictionary`2 parameters)\r\n   at System.Web.Script.Services.WebServiceMethodData.CallMethodFromRawParams(Object target, IDictionary`2 parameters)\r\n   at System.Web.Script.Services.RestHandler.InvokeMethod(HttpContext context, WebServiceMethodData methodData, IDictionary`2 rawParams)\r\n   at System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(HttpContext context, WebServiceMethodData methodData)","ExceptionType":"System.InvalidOperationException"}

I've tried having my web method in a bunch of different ways, such as but not limited to:

<System.Web.Services.WebMethod()> _
Public Shared Function validateTask(ByVal newTask As TaskBO)

Or with a bunch of individual parameters as strings.

What is the correct way to accomplish what I'm trying to do? What do I not understand about formatting JSON objects?

Thanks for your help!

Answer 1

The web service expects an item with the key "newTask" (as shown by your method's parameter). Your request will be sent as:

{
    "TaskName": "stuff",
    "TaskDescription": "stuff",
    "SQLObjectID": "stuff",
    "WarehouseSQLObjectID": "stuff"
}

But you really need it to be:

{
    "newTask": {
        "TaskName": "stuff",
        "TaskDescription": "stuff",
        "SQLObjectID": "stuff",
        "WarehouseSQLObjectID": "stuff"
    }
}

So change your $.ajax() call to be:

data: JSON.stringify({
    newTask: newTask
}),
contentType: "application/json; charset=utf-8",

Answer 2

• If you are using a separate js file for this code to work, verify the client ids

• If there are more properties on the class for the newTask , you can always exclude unnecessary properties from json object using delete operator.( for example: delete newTask.UnnecessaryProperty)