Convert DataSet or XML to JSON using VB.NET

I searched high and wide for something simple to do this and every function I found basically reinvented the wheel from scratch. If you do any amount of searching, you can find the JavaScriptSerializer object which will convert objects to JSON. Sounds easy enough...WRONG! Even converting an empty DataSet will return a circular reference exception.

On a similar note, I found several articles claiming to convert XML to JSON using the same function. The "solution" was something like this:

Dim jss As New JavaScriptSerializer
Dim jsonString As String = jss.Serialize(DataSet1.GetXML())

I tried this thinking it made sense. But instead of serializing the data in the XML, it simply dumps the entire XML string into a single element in the JSON string. I'm pretty sure that's not what anyone wants it to do.

So how do you do it? Well, there are a number of methods, but I found the quickest and easiest is to just convert your DataSet to a Dictionary object, then use the JavaScriptSerializer to make the conversion.

Here's the code:

Function DataSetToJSON(ds As DataSet) As String
    Dim dict As New Dictionary(Of String, Object)

    For Each dt As DataTable In ds.Tables
        Dim arr(dt.Rows.Count) As Object

        For i As Integer = 0 To dt.Rows.Count - 1
            arr(i) = dt.Rows(i).ItemArray
        Next

        dict.Add(dt.TableName, arr)
    Next

    Dim json As New JavaScriptSerializer
    Return json.Serialize(dict)
End Function

If you're looking to convert XML to JSON and write the least amount of code, you can just write it to a DataSet on the fly like this:

DataSetToJSON(New DataSet().ReadXml(xmlString))

I know it sounds crazy, but both of these methods are really simple and execute really fast. And you don't need to know about XLT or anything else. Oh, and the only libraries you need are System.Data and System.Web.Script.Serialization.

When it comes around to referencing the JSON object from your browser, you can access the elements like so:

jsonString.TableName[rowIndex][columnIndex]

If anyone knows how to make the conversion, you can reference it by jsonString.TableName.Column[rowIndex], I would love to see it.