Hello,
        This time i tried to sorting and Filtering Rows in a DataGrid.I coded like the following.

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


        Dim gstrSortOrder As String
        Dim gstrFindText As String
        Dim dst As DataSet
        Dim con As SqlConnection
        Dim dad As SqlDataAdapter
        Dim dvw As DataView


        If Page.IsPostBack Then
            'gstrSortOrder = "ProductName"
            gstrFindText = "ProductName LIKE '*" & TextBox1.Text & " *'"
        Else
            gstrSortOrder = "ProductID"
            TextBox1.Text = "Tofu"
        End If

        BindDataGrid()


    End Sub

    Public Sub BindDataGrid()
        Dim gstrSortOrder As String
        Dim gstrFindText As String
        Dim dst As DataSet
        Dim con As SqlConnection
        Dim dad As SqlDataAdapter
        Dim dvw As DataView

        dst = New DataSet()
        con = New SqlConnection("Server=cabin61;UID=sa;PWD=;Database =Northwind")
        con.Open()
        dad = New SqlDataAdapter("Select * From Products", con)
        dad.Fill(dst, "Products")
        dvw.Sort = gstrSortOrder
        dvw.RowFilter = gstrFindText
        DataGrid1.DataSource = dvw
        DataGrid1.DataBind()
        con.Close()
    End Sub
    Public Sub SortRows(ByVal objSender As Object, ByVal objArgs As DataGridSortCommandEventArgs)
        Dim gstrSortOrder As String
        gstrSortOrder = objArgs.SortExpression.ToString()
        BindDataGrid()
    End Sub

       These codes are given in the wrox book. but it is not working.The error message returned was " object reference not set to an instance of an object " and the line containing error is dvw.Sort = gstrSortOrder. How to solve this problem ?

Sorry, but some line of codes have not been written by me, thats why the error was coming. Now the data can be viewed easily. But still there is some problem.The data retrieved can be sorted by any columnID, but the filtering is not happening. Is there any other lines of code to be inserted, or there is some error in the codes i wrote ? advise please

I think the problem is that you have gstrSortOrder and gstrFindText declared both globally and locally in the BindDataGrid function. Remove the declarations from the BindDataGrid function.

 I tried this also, i declared the variables globally, removing them from the BindDataGrid function. But it is not working. I am providing the code once again below.Please check this.

Imports System.Data.SqlClient
Public Class WebForm3
    Inherits System.Web.UI.Page
    Protected WithEvents TextBox1 As System.Web.UI.WebControls.TextBox
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button
    Protected WithEvents DataGrid1 As System.Web.UI.WebControls.DataGrid
    Protected WithEvents Label1 As System.Web.UI.WebControls.Label
    Dim gstrSortOrder As String
    Dim gstrFindText As String



    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


        If Page.IsPostBack Then

            gstrFindText = "LastName LIKE '*" & TextBox1.Text & " *'"
        Else
            gstrSortOrder = "EmployeeID"
            TextBox1.Text = "Ann"

        End If

        BindDataGrid()

    End Sub


    Public Sub BindDataGrid()

        Dim dst As DataSet
        Dim con As SqlConnection
        Dim dad As SqlDataAdapter
        Dim dvw As DataView

        dst = New DataSet()
        con = New SqlConnection("Server=cabin61;UID=sa;PWD=;Database =Northwind")
        con.Open()
        dad = New SqlDataAdapter("Select * From Employees ", con)
        dad.Fill(dst, "Employees")
        dvw = dst.Tables("Employees").DefaultView

        dvw.Sort = gstrSortOrder
        dvw.RowFilter = gstrFindText
        DataGrid1.DataSource = dvw
        DataGrid1.DataBind()
        con.Close()
    End Sub

    Public Sub SortRows(ByVal objSender As Object, ByVal objArgs As DataGridSortCommandEventArgs)

        gstrSortOrder = objArgs.SortExpression.ToString()
        BindDataGrid()
    End Sub


End Class

 Here also the same problem is coming, i can sort using any column name but filtering is not possible.

Also is it possible to link each column headers differently to some different pages such that on clicking on them we can navigate to some other page ?

A) One problem I didn't catch before is that you are binding the data every time the page loads. Move BindDataGrid() into the Else of the If in page_load.
Then add handlers for the two text boxes you want to filter by. Have the OnChange event for those text boxes set the dataset's rowfilter and rebind.

B) I'm not sure if it matters, but I would call .DefaultView after you set the row filter. That's the way I do it and it works.

C) Your filter doesn't look right. You have * as the wildcard, try % instead.

You said that you would call .DefaultView after setting the row filter, but i cant understand how a dataview can be filtered before we attach a defaultview, and if there is any way i dont know it. Please make me understand.

The filter * is for Access, % is for SQL server and others ISO Standard SQL

~ Human Knowledge Belongs to the World !

if you are doing asp.net then u should create a hyperlink column.

<asp:HyperLinkColumn Target="_self"
     DataNavigateUrlField="FieldKey"
     DataNavigateUrlFormatString="./index.aspx/URL={0}"
     DataTextField=""
     HeaderText=""
>
</asp:HyperLinkColumn>

~ Human Knowledge Belongs to the World !

Hi, thanks for the reply desmond047.But i was trying something different.Let me make it clear.
I have displayed the data from the database using datagrid.Suppose we have three column names in the displayed employee table viz. employeeid,employeename and division. When the data are displayed, these three fields are the output.Now I want that, the employee names that are displayed are the hyperlinks to another page where their personal informations are stored.
  This was the application I was trying. Can you tell me how to do that ? I dont want to use the hyperlink column as every member in this column navigates to the same page and it leaves no option to navigate to different pages from different fields.

This works fine for me...

_objData.DefaultView.RowFilter = _strFilter
_objData.DefaultView.Sort = _strSort
grdSR.DataSource = _objData.DefaultView
grdSR.DataBind()