I couldn't display gridview with data even there is no error. Why?

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I tried a very basic databinding in a webform with SQLSERVER2008..everything seems to be perfect(NO ERRORS),but still couldn't display it on browser while it runs..i see nothing jus a blank page.
What could be wrong?
-i lookedupon db connection its fine

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Sql;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlConnection con =new SqlConnection ("data source=.; database=sample ; integrated security=SSPI; ");
        SqlCommand cmd = new SqlCommand("Select * from Login_Info", con);
        con.Open();
        SqlDataReader rdr = cmd.ExecuteReader();
        GridView1.DataSource = rdr;
        GridView1.DataBind();
        con.Close();
    }
}

Posted 18-Feb-15 4:20am

Member 1097736

Updated 18-Feb-15 4:48am

v3

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Richard Deeming · Answer 1 · 2015-02-18T06:10:00

Solution 1

You're binding the GridView in the SelectedIndexChanged event for the same GridView. Since the grid doesn't have any data, that event will never fire.

Try binding the grid from the Page_Load event instead. You'll also want to wrap it in an if (!IsPostBack) { ... } block.

C#

using System;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            BindTheGrid();
        }
    }

    private void BindTheGrid()
    {
        using (SqlConnection con = new SqlConnection ("data source=.; database=sample ; integrated security=SSPI; "))
        using (SqlCommand cmd = new SqlCommand("Select * from Login_Info", con))
        {
            con.Open();
            using (SqlDataReader rdr = cmd.ExecuteReader())
            {
                GridView1.DataSource = rdr;
                GridView1.DataBind();
            }
        }
    }
}

Posted 18-Feb-15 6:10am

Richard Deeming

Comments

[no name] 18-Feb-15 12:25pm

+5 for that

Member 1097736 18-Feb-15 12:32pm

@RICHARD Deeming ...i followed up an video tutorial from youtube
LINK-> https://www.youtube.com/watch?v=aoFDyt8oG0k
meanwhile he did the same and got output!

still the code aint helping out!

Richard Deeming 18-Feb-15 12:36pm

If you look carefully at the code he's typed, you'll see he's binding the list in the Page_Load event.

You're trying to bind it in the GridView1_SelectedIndexChanged event.

The Page_Load event fires every time the page is loaded. The GridView1_SelectedIndexChanged event only fires when GridView1 already has some data, and the use selects a different row.

Member 1097736 18-Feb-15 12:42pm

THanks RICHARD! _/\_

Member 1097736 18-Feb-15 13:19pm

So will this code be perfect?
<pre>#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Sql;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(" data source=.; database=sampl ; integrated security=SSPI; ");
SqlCommand cmd = new SqlCommand("Select * from studet", con);
con.Open();
SqlDataReader rdr = cmd.ExecuteReader();
GridView1.DataSource = rdr;
GridView1.DataBind();
con.Close();
}
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{

}
}

Richard Deeming 18-Feb-15 13:31pm

That should work, and seems to match the code from your tutorial.

Member 1097736 20-Feb-15 2:07am

@Richard i tried running the same..i encouter an error- A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: Named
Pipes Provider, error: 40 - Could not open a connection to SQL
Server)" pointing to con.open(); line.
Regarding connection I have connected the paricular database in SERVER EXPLORER.

Richard Deeming 20-Feb-15 8:29am

That error means that the server you have specified in your connection string doesn't exist.

If SQL is installed on the same computer as your code, then the connection string should be:
Server=.;Database=sample;Trusted_Connection=True;

If it's installed on a different computer, then you'll need to update the Server value.