whats is going with code?Exception: Object reference not set to an instance of an object [duplicate]

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• What is a NullReferenceException and how do I fix it? 18 answers

I am working on gridview in asp.net c#. I have checkbox in first column of my gridview and with the checkbox i want to delete multiple row. But when I select rows and click delete button than chekcbox is not shown as checked.

protected void btnDelete_Click(object sender, EventArgs e) { int flag = 0; this.ConnectToDatabase();

        for (int i = 0; i < myGrid.Rows.Count; i++)
        {
            CheckBox ck = (CheckBox)myGrid.Rows[i].FindControl("chkItem");

            if (ck.Checked)
            {
                string storid = myGrid.Rows[i].Cells[1].Text;
                        MySqlCommand cmd = new MySqlCommand("Delete From MyFiles where ID =" + Int32.Parse(storid), conn);
                           //  message += row.Cells["FileID"].Value.ToString();
                            cmd.ExecuteNonQuery();
                            flag = 1;
            }
        }

        //foreach (GridViewRow row in myGrid.Rows)
        //{
        //    if (row.RowType == DataControlRowType.DataRow)
        //    {

        //        if (((CheckBox)row.FindControl("chkItem")).Checked)
        //        {
        //            string storid = row.Cells[1].Text;
        //            MySqlCommand cmd = new MySqlCommand("Delete From MyFiles where ID =" + Int32.Parse(storid), conn);
        //            //  message += row.Cells["FileID"].Value.ToString();
        //            cmd.ExecuteNonQuery();
        //            flag = 1;
        //        }
        //    }
        //}
        conn.Close();
        if (flag == 1)
        {
            string mj = "Deleted Sucessfully";
            ClientScript.RegisterStartupScript(this.GetType(), "yourMessage", "alert('" + mj + "');", true);
            Response.Redirect("Main.aspx");

        }
        else
        {
            string msj = "Select Item to delete";
            ClientScript.RegisterStartupScript(this.GetType(), "yourMessage", "alert('" + msj + "');", true);

        }


    }

...........................this grid view code.