paging and sorting in grid view - asp.net

Question

i have a code performing paging and sorting in grid view.
(bing_grid is user defined function)
public void bind_grid()
{
con = new SqlConnection();
con.ConnectionString = "Data Source=STIRAPC105;InitialCatalog=anitha;Integrated Security=True";
con.Open();
SqlDataAdapter sqa = new SqlDataAdapter("select * from employees", con);
DataSet ds = new DataSet();
sqa.Fill(ds);
DataTable mytab = ds.Tables[0];
GridView1.DataSource = mytab;
GridView1.DataBind();
//con.Close();
}
code for paging
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
bind_grid();
}
code for sorting
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable dt = GridView1.DataSource as DataTable;
if (dt != null)
{
DataView dataview = new DataView(dt);
dataview.Sort = e.SortExpression + " " + sort_grid(e.SortDirection);
GridView1.DataSource = dataview;
GridView1.DataBind();
}
}
user defined code for sorting
public string sort_grid()
{
string newSortDirection = String.Empty;
switch (sortDirection)
{
case SortDirection.Ascending:
newSortDirection = "ASC";
break;
case SortDirection.Descending:
newSortDirection = "DESC";
break;
}
return newSortDirection;
}
paging works, Errors was:
1. "no overload for method 'sort_grid' takes 1 argument" (dataview.Sort = e.SortExpression + " " + sort_grid(e.SortDirection);)
2.The name 'sortDirection does not exist in the current context. (switch (sortDirection))
Help me friends.

Answer 1

this method:
public string sort_grid()
takes no arguments but you are trying to call it with e.SortDirection:
dataview.Sort = e.SortExpression + " " + sort_grid(e.SortDirection);
You must change the signature of sort_grid() to
sort_grid(SortDirection sortDirection)
This will also solve your second problem, which you are trying to use sortDirection variable, before declaring it in the method sort_grid.