Sorting GridView Formed With Data Set - asp.net

Question

The following code sample is for sorting a GridView formed With a DataSet.
Source: http://www.highoncoding.com/Articles/176_Sorting_GridView_Manually_.aspx
But it is not displaying any output.
There is no problem in sql connection.
I am unable to trace the error, please help me.
Thank You.
public partial class _Default : System.Web.UI.Page
{
private const string ASCENDING = " ASC";
private const string DESCENDING = " DESC";
private DataSet GetData()
{
SqlConnection cnn = new SqlConnection("Server=localhost;Database=Northwind;Trusted_Connection=True;");
SqlDataAdapter da = new SqlDataAdapter("SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES", cnn);
DataSet ds = new DataSet();
da.Fill(ds);
return ds;
}
public SortDirection GridViewSortDirection
{
get
{
if (ViewState["sortDirection"] == null)
ViewState["sortDirection"] = SortDirection.Ascending;
return (SortDirection)ViewState["sortDirection"];
}
set { ViewState["sortDirection"] = value; }
}
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
string sortExpression = e.SortExpression;
if (GridViewSortDirection == SortDirection.Ascending)
{
GridViewSortDirection = SortDirection.Descending;
SortGridView(sortExpression, DESCENDING);
}
else
{
GridViewSortDirection = SortDirection.Ascending;
SortGridView(sortExpression, ASCENDING);
}
}
private void SortGridView(string sortExpression, string direction)
{
// You can cache the DataTable for improving performance
DataTable dt = GetData().Tables[0];
DataView dv = new DataView(dt);
dv.Sort = sortExpression + direction;
GridView1.DataSource = dv;
GridView1.DataBind();
}
}
aspx page
asp:GridView ID="GridView1" runat="server" AllowSorting="True" OnSorting="GridView1_Sorting">
/asp:GridView>

Answer 1

Problem is with Page Load event when you fill the data you add it inside if(!IsPostBack) condition .

Answer 2

In this article, there is explained how to sort the GridView data in ASP.NET.
GridvIew control is a powerful data grid control that allows us to display the data in tabular format with sorting and pagination. It also allows us to manipulate the data as well.
http://www.dotnetfunda.com/articles/article1598-how-to-sort-the-gridview-data-in-aspnet.aspx

Answer 3

//Code Behind
DataSet ds = new DataSet();
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
gvbind();
}
}
protected DataSet gvbind() // Binding the gridview using Dataset and I am using stored procedure "Proc_Displayinfo"
{
con.Open();
SqlCommand command = new SqlCommand("Proc_Displayinfo", con);
SqlDataAdapter adpt = new SqlDataAdapter(command);
DataSet ds = new DataSet();
adpt.Fill(ds);
GridView1.DataSource = ds.Tables[0];
GridView1.DataBind();
con.Close();
return ds;
}
public SortDirection dir
{
get
{
if (ViewState["dirState"] == null)
{
ViewState["dirState"] = SortDirection.Ascending;
}
return (SortDirection)ViewState["dirState"];
}
set
{
ViewState["dirState"] = value;
}
}
protected void Gridview1_Sorting(object sender, GridViewSortEventArgs e)
{
gvbind();
DataTable dt = gvbind().Tables[0];
{
string SortDir = string.Empty;
if (dir == SortDirection.Ascending)
{
dir = SortDirection.Descending;
SortDir = "Desc";
}
else
{
dir = SortDirection.Ascending;
SortDir = "Asc";
}
DataView sortedView = new DataView(dt);
sortedView.Sort = e.SortExpression + " " + SortDir;
GridView1.DataSource = sortedView;
GridView1.DataBind();
}
}
// Source Code
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="StudentId" onsorting="Gridview1_Sorting" AllowSorting="True">
<asp:TemplateField HeaderText="StudentID" SortExpression="StudentID">
<ItemTemplate>
<asp:Label ID="LBLStudentID" runat="server" Text='<%# Eval("StudentID") %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TXTStudentID" runat="server" Text='<%# Eval("StudentID") %>'></asp:TextBox>
</EditItemTemplate>