从ASP.NET Web API返回的JavaScript数组未定义，GET方法

Question

I have the current GET method in C#:

public CustomObject[] GetSample(long id)
{
    CustomObject[] arr;

    var topt = new TransactionOptions();
    topt.IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted;

    using (var tscope = new TransactionScope(TransactionScopeOption.Required, topt))
    {
        using (var context = new DatabaseEntities())
        {
            context.Database.Connection.Open();

            /*STARTING HERE*/   
            var co = 
                from a in context.tableA /*... some query conditions*/

                select new CustomObject()
                {
                    int_field = a
                };

            //change co from IQueryable<CustomObject> to CustomObject[]
            arr = co.ToArray();

            for (var i = 0; i < arr.Length; i++)
            {
                arr[i].string_field = arr[i].int_field.intToString();   //a custom method that converts int to string
            }
            /*ENDING HERE*/

        }
        tscope.Complete();
    }
    return arr;
}

I'm calling it from some JavaScript code:

function doQuery(id) {
    $.getJSON(somePath + '/GetSample/' + id)
        .done(function (data) {
            //data should be of type CustomObject[]
            for (var i = 0; i < data.length; i++) {
                appendToTable(data[i]); //this function displays each CustomObject in a table
            }
        });
}

But the result is that everything except for the first element in the array is undefined:

string_field     int_field
--------------------------
"7"              7            //data[0]
undefined        undefined    //data[1]
undefined        undefined    //data[2]
...              ...          //...

When I set a breakpoint and look at data , the other fields are actually missing:

data
    [0]
        __proto__
        $id
        string_field    //has value of "7"
        int_field       //has value of 7
    [1]
        __proto__
        $id             //the other fields are missing
    [2]
        ....

Can anyone explain why this is and how to fix it? Could the return type of the GET method be a problem? Should I not use getJSON ?

Any help is appreciated.

Answer 1

Use response.data in callback function

function doQuery(id) {
    $.getJSON(somePath + '/GetSample/' + id)
        .done(function (response) {
             //data should be of type CustomObject[]
            for (var i = 0; i < response.data.length; i++) {
                appendToTable(response.data[i]); //this function displays each CustomObject in a table
            }
        });
}