create sorting for a Grid View

Code to create Sorting for a GridView in ASP.net in Code Behind?

Step 1: Add the Property in your Class 

public string SortField {
            get {
                return (string) ViewState["_sortField"];
            }
            set {
                ViewState["_sortField"] = value;
            }
        }
        public string SortDir {
            get {
                return (string) ViewState["_sortDir"];
            }
            set {
                ViewState["_sortDir"] = value;
            }
        }

setp 2 : Enable the Gridview Sorting using the Events

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) {

            if (e.SortExpression == SortField && SortDir != "desc") {
                SortDir = "desc";
            }
            else {
                SortDir = "asc";
            }

            SortField = e.SortExpression;

            DoDataBind();
        }

step 3 : Enable the sorting expression in grid

<asp:BoundField DataField="FIRSTNAME" HeaderText="First Name" SortExpression="FIRSTNAME" />

 

step 4 : Bind the Data source As follows

DataTable dt = yourDataSet.Tables[0];
dt.DefaultView.Sort = SortField + " " + SortDir;
GridView1.DataSource = dt.DefaultView;
GridView1.DataBind();
 

step 5 : Add the property in Gridview

AllowSorting="true"