Webgrid Exception in mvc

Question

Exception:-A data source must be bound before this operation can be performed.

 

I am using webgrid to display data and i am using validation ,when my code (vcCtgCode) is null 

 it display above exception ,How to Overcome the exception.

 

 

@model IEnumerable<******.Model.tblMstCategory_CTG>

<div>

@{

var grid = new WebGrid(Model, ajaxUpdateContainerId: "inCtgId");

@grid.GetHtml(

tableStyle: "webgrid-table",

headerStyle: "webgrid-header",

footerStyle: "webgrid-footer",

alternatingRowStyle: "webgrid-alternating-row",

selectedRowStyle: "webgrid-selected-row",

rowStyle: "webgrid-row-style",

htmlAttributes: new { id = "Grid" },

//mode: WebGridPagerModes.All,

columns: new[]

{

grid.Column("inCtgId",header:"Id")

,grid.Column("vcCtgCode",header:"Code",format: (item)=> string.IsNullOrEmpty(item.vcCtgCode)?string.Empty:item.vcCtgCode)

})

}

</div>