Thanks for using Syncfusion Products.
We have analyzed your code snippets and found that you have bound datasource to grid from code behind method Loadsalesorder. But in this method material code and material name values are not provided and so it was shown empty in grid.
We have now modified the this method and please find the code snippet below.
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public static List<Materials> Loadsalesorder(string code)
List<Materials> product = new List<Materials>();
if (code == "10001")
product.Add(new Materials(1, "Product1", 10001, "ALFKI"));
else if (code == "10002")
product.Add(new Materials(1, "Product2", 10002, "ANATR"));
We have also modified your sample and the same can be downloadable from below link
Alan Sangeeth S