Why my Gridview will disappear after clicking on page 2(Paging)

Question

I have 7 records in my database table which is called EntryTable. I set page limit to 5 records for each page. So page 1 will have 5 records, and page2 will have 2 records. But after I click Search All and click page 2, the whole gridview disappear.

After Searching for All

After clicking page 2

public partial class Search : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Page.IsPostBack == false)
        {
            bindResultGridView();

        }

        string memName = (String)Session["UserName"];
        if (Session["Username"] != null && Session["Username"] != String.Empty)
        {
            //txtUserName.Text = "Welcome, " + memName + "!";


        }
    }

    protected void SearchBlog(object sender, EventArgs e)
    {
        String ConStr = ConfigurationManager.ConnectionStrings["BlogConnectionString"].ConnectionString;
        SqlConnection con = new SqlConnection(ConStr);

        try
        {
            string invalid = txtSearch.Text;

            String SQL = null;

            if (invalid == "all")
            {
                SQL = "SELECT BlogID, AdminNumber, Name, Description FROM [EntryTable]";
            }
            else
            {
                SQL = "SELECT BlogID, AdminNumber, Name, Description FROM [EntryTable] WHERE AdminNumber LIKE @searchAdminNumber OR BlogType LIKE @searchBlogType OR Name LIKE @searchName";
            }


            SqlCommand cmd = new SqlCommand(SQL, con);
            con.Open();

            cmd.Parameters.Add("@searchBlogType", SqlDbType.NVarChar, 50);
            cmd.Parameters["@searchBlogType"].Value = txtSearch.Text + "%";

            cmd.Parameters.Add("@searchName", SqlDbType.NVarChar, 50);
            cmd.Parameters["@searchName"].Value = txtSearch.Text + "%";

            cmd.Parameters.Add("@searchAdminNumber", SqlDbType.NVarChar, 50);
            cmd.Parameters["@searchAdminNumber"].Value = txtSearch.Text + "%";

            SqlDataReader reader = cmd.ExecuteReader();
            DataTable dt = new DataTable();
            dt.Load(reader);
            grdResult.DataSource = dt;
            grdResult.DataBind();
            lblError.Text = "";


            if (dt.Rows.Count > 0)
            {
                lblError.Text = null;
            }
            else
            {
                lblError.Text = "Record not found";
            }

            reader.Close();
        }
        catch (Exception)
        {
            lblError.Text = "Error!";
            //lblOrderError.Text = ex.Message;
        }
        finally
        {
            con.Close();
        }
    }



    private void bindResultGridView()
    {
        String ConStr = ConfigurationManager.ConnectionStrings["BlogConnectionString"].ConnectionString;
        SqlConnection con = new SqlConnection(ConStr);

        try
        {
            string invalid = txtSearch.Text;

            String SQL = null;

            if (invalid == "all")
            {
                SQL = "SELECT BlogID, AdminNumber, Name, Description FROM [EntryTable]";
            }
            else
            {
                SQL = "SELECT BlogID, AdminNumber, Name, Description FROM [EntryTable] WHERE AdminNumber LIKE @searchAdminNumber OR BlogType LIKE @searchBlogType OR Name LIKE @searchName";
            }


            SqlCommand cmd = new SqlCommand(SQL, con);
            con.Open();

            cmd.Parameters.Add("@searchBlogType", SqlDbType.NVarChar, 50);
            cmd.Parameters["@searchBlogType"].Value = txtSearch.Text;

            cmd.Parameters.Add("@searchName", SqlDbType.NVarChar, 50);
            cmd.Parameters["@searchName"].Value = txtSearch.Text;

            cmd.Parameters.Add("@searchAdminNumber", SqlDbType.NVarChar, 50);
            cmd.Parameters["@searchAdminNumber"].Value = txtSearch.Text;



            SqlDataReader reader = cmd.ExecuteReader();
            DataTable dt = new DataTable();
            dt.Load(reader);
            grdResult.DataSource = dt;
            grdResult.DataBind();
            lblError.Text = "";

            reader.Close();
        }
        catch (SqlException ex)
        {
            lblError.Text = "Error:" + ex.Message.ToString();
        }
        finally
        {
            con.Close();
        }
    }

    protected void btnSearch_Click(object sender, EventArgs e)
    {

    }



    protected void grdResult_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (string.Compare(e.CommandName, "Page", true) != 0)
        {
            Response.Redirect("~/ResultDetails.aspx?cat=" + e.CommandArgument);
        }
    }


    protected void grdResult_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        int newPageIndex = e.NewPageIndex;
        grdResult.PageIndex = newPageIndex;
        bindResultGridView();
    }
}

EDITED

AFTER clicking on page 2

protected void Page_Load(object sender, EventArgs e)
{

        bindResultGridView();



    string memName = (String)Session["UserName"];
    if (Session["Username"] != null && Session["Username"] != String.Empty)
    {
        //txtUserName.Text = "Welcome, " + memName + "!";


    }
}

Answer 1

It should work. Maybe the grdResult_PageIndexChanging event doesn't fire

So create a break point on

    int newPageIndex = e.NewPageIndex;

or on this line

    grdResult.PageIndex = newPageIndex;

If this event doesn't run, maybe your result grid has not been attached this event. Please try to reattach it again and I think, chances will work.

EDITS:

finally edit with this

    else if (invalid == "") { 
     SQL = "SELECT BlogID, AdminNumber, Name, Description FROM [EntryTable]"; 
    }