Convert c# datatable to JSON array to pass to Google Charts

Question

I want to pass C# datatable result to my chart but I get this error saying 'Argument given to addRows must be either a number or an array'

C#

 string result = "";
 result = "[";
 foreach (DataRow row in dt.Rows)
 {
 result += "['"+row[0]+"',"+row[1]+"],";
 }
 result = result.TrimEnd(',')+"]";
 txtJsonData.Value = result;

JavaScript

 var data = new google.visualization.DataTable();
 data.addColumn('string', 'Page');
 data.addColumn('number', 'Followers');
 var chartData = document.getElementById('txtJsonData').value;
 data.addRows(chartData);

SampleData

"[['@flu',401],['@weightloss',1068],['@heartdiseases',223],['@diabetesfacts',356]]"

Answer 1

Your variable chartData contains a string. You need to parse it before passing it to addRows.

data.addRows(JSON.parse(chartData));

JSON.parse() takes a string, and will return the corresponding Javascript object. If your code needs to run on Internet Explorer <= 8 (which doesn't include the JSON related functions), you will need to include json2.js, that you can get from https://github.com/douglascrockford/JSON-js

• Tweety01: Thanks for reply.I have tried this already but it gives me error Uncaught SyntaxError: Unexpected token " ' "
• Najkin: That's because strings in JSON must be enclosed in double quotes, not single quotes. You shouldn't generate JSON by hand like, there are many libraries that will do for you, better and in a safer way.
• zoranmax: you have probably found an answer already, in case you haven't as Riokmij mentioned, you can use an external library to generate the JSON literal (server side). One possibility is to use Google DataTable .Net Wrapper which will allow you to translate in a very easy way any List or even System.DataTable into the Google DataTable format.