error when Adding new row in gridview: System.NullReferenceException: Object reference not set to an instance of an object

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Hi,

I have the error:
System.NullReferenceException: Object reference not set to an instance of an object
when i try to insert a new row in a grid view.

Below is the GridView:

ASP.NET

<asp:GridView ID="gvTaskDetails" runat="server" AutoGenerateColumns="false" BackColor="LightGoldenrodYellow"
                    BorderColor="Tan" BorderWidth="1px" CellPadding="2" ForeColor="Black"  GridLines="None" OnRowCommand="gvTaskDetails_rowCommand" 
                    OnRowDataBound="gvTaskDetails_RowDataBound" style="width: 970px">
                       <Columns>
                            <asp:TemplateField HeaderText="Name" ItemStyle-CssClass="Item_txtGrid" HeaderStyle-CssClass="Item_txtGrid">
                                <ItemTemplate>
                                    <asp:TextBox ID="txt_GridName" runat="server" Width="200px" Text='<%# Eval("NAME") %>' Visible="false" CssClass="textfield"></asp:TextBox>
                                    <asp:Label ID="lblGrdName" Width="200px" runat="server" CssClass="Item_txtGrid" Text='<%# Eval("NAME") %>'></asp:Label>
                                </ItemTemplate>
                           </asp:TemplateField>
                           <asp:TemplateField HeaderText="Description" ItemStyle-CssClass="Item_txtGrid" HeaderStyle-CssClass="Item_txtGrid">
                                <ItemTemplate>
                                    <asp:TextBox ID="txt_GridDesc" runat="server" Width="200px" Text='<%# Eval("DESCRIPTION") %>' Visible="false" CssClass="textfield"></asp:TextBox>
                                    <asp:Label ID="lblGrdDesc" Width="170px" runat="server" CssClass="Item_txtGrid" Text='<%# Eval("DESCRIPTION") %>'></asp:Label>
                                </ItemTemplate>
                           </asp:TemplateField>
                           <asp:TemplateField HeaderText="AssignedTo" ItemStyle-CssClass="Item_txtGrid" HeaderStyle-CssClass="Item_txtGrid">
                                <ItemTemplate>
                                    <asp:TextBox ID="txt_GridAssigned" runat="server" Width="200px" Text='<%# Eval("ASSIGNEDTO") %>' Visible="false" CssClass="textfield"></asp:TextBox>
                                     <asp:Label ID="lblGrdAssigned" Width="170px" runat="server" CssClass="Item_txtGrid" Text='<%# Eval("ASSIGNEDTO") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="StartDate" ItemStyle-CssClass="Item_txtGrid" HeaderStyle-CssClass="Item_txtGrid">
                                <ItemTemplate>
                                    <asp:TextBox ID="txt_GridStartDate" runat="server" Width="200px" Text='<%# Eval("STARTDATE") %>' Visible="false" CssClass="textfield"></asp:TextBox>
                                    <asp:Label ID="lblGrdStartDate" Width="170px" runat="server" CssClass="Item_txtGrid" Text='<%# Eval("STARTDATE") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="EndDate" ItemStyle-CssClass="Item_txtGrid" HeaderStyle-CssClass="Item_txtGrid">
                                <ItemTemplate>
                                    <asp:TextBox ID="txt_GridEndDate" runat="server" Width="200px" Text='<%# Eval("ENDDATE") %>' Visible="false" CssClass="textfield"></asp:TextBox>
                                    <asp:Label ID="lblGrdEndDate" Width="170px" runat="server" CssClass="Item_txtGrid" Text='<%# Eval("ENDDATE") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField>
                                <ItemTemplate>
                                    <asp:ImageButton ID="lnkEdit" runat="server" AlternateText="Edit" CausesValidation="False" CommandName="EditClick" ImageUrl="~/Images/Proj_edit.gif" CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" />
                                    <asp:ImageButton ID="lnkUpdate" runat="server" AlternateText="Update" CausesValidation="False" CommandName="UpdateClick" ImageUrl="~/Images/Proj_update.gif" CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" />
                                    <asp:ImageButton ID="lnkDelete" runat="server" AlternateText="Delete" CausesValidation="False" CommandName="DeleteClick" ImageUrl="~/Images/Proj_delete.gif" CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" />
                                </ItemTemplate>
                            </asp:TemplateField>
                                                                                                                                        
                        </Columns>
                        <AlternatingRowStyle BackColor="PaleGoldenrod" />
                        <FooterStyle BackColor="Tan" />
                        <HeaderStyle BackColor="Tan" Font-Bold="True" HorizontalAlign="Center" />
                        <PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Right" />
                        <SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
                    </asp:GridView>

Below is the code of AddToGrid function called in the event btnAddRowToGrid_Click:

C#

private void AddToGrid()
    {
        
        try
        {
           DataTable dtable = new DataTable("ROW");
            
            if (Session["ShareHolderDetails"] != null)
            {
                dtable = (DataTable)Session["ShareHolderDetails"];
            }
            else
            {

                dtable.Columns.Add(new DataColumn("NAME"));
                dtable.Columns.Add(new DataColumn("DESCRIPTION"));
                dtable.Columns.Add(new DataColumn("ASSIGNEDTO"));
                dtable.Columns.Add(new DataColumn("STARTDATE"));
                dtable.Columns.Add(new DataColumn("ENDDATE"));

            }
            DataRow drow = dtable.NewRow();
            drow["NAME"] = string.Empty;
            drow["DESCRIPTION"] = string.Empty;
            drow["ASSIGNEDTO"] = string.Empty;
            drow["STARTDATE"] = string.Empty;
            drow["ENDDATE"] = string.Empty;

            dtable.Rows.Add(drow);


            gvTaskDetails.DataSource = dtable;
            gvTaskDetails.DataBind();
            foreach (GridViewRow gRow in gvTaskDetails.Rows)
            {
                
                Label lblGrdName = (Label)gRow.FindControl("lblGrdName");
                Label lblGrdDescription = (Label)gRow.FindControl("lblGrdDescription");
                Label lblGrdAssignedTo = (Label)gRow.FindControl("lblGrdAssignedTo");
                Label lblGrdStartDate = (Label)gRow.FindControl("lblGrdStartDate");
                Label lblGrdEndDate = (Label)gRow.FindControl("lblGrdEndDate");

                TextBox txtGrdName = (TextBox)gRow.FindControl("txtGrdName");
                TextBox txtGrdDescription = (TextBox)gRow.FindControl("txtGrdDescription");
                TextBox txtGrdAssignedTo = (TextBox)gRow.FindControl("txtGrdAssignedTo");
                TextBox txtGrdStartDate = (TextBox)gRow.FindControl("txtGrdStartDate");
                TextBox txtGrdEndDate = (TextBox)gRow.FindControl("txtGrdEndDate");

                ImageButton lnkEdit = (ImageButton)gRow.FindControl("lnkEdit");
                ImageButton lnkUpdate = (ImageButton)gRow.FindControl("lnkUpdate");
                ImageButton lnkDelete = (ImageButton)gRow.FindControl("lnkDelete");

                if (lblGrdName.Text.ToString() == string.Empty)
                {
                    txtGrdName.Visible = true;
                    txtGrdDescription.Visible = true;
                    txtGrdAssignedTo.Visible = true;
                    txtGrdStartDate.Visible = true;
                    txtGrdEndDate.Visible = true;

                    lblGrdName.Visible = false;
                    lblGrdDescription.Visible = false;
                    lblGrdAssignedTo.Visible = false;
                    lblGrdStartDate.Visible = false;
                    lblGrdEndDate.Visible = false;


                    lnkUpdate.Visible = true;
                    lnkEdit.Visible = false;
                    lnkDelete.Visible = true;
                }
            }
            Session["ShareHolderDetails"] = dtable;

        }
        catch (Exception ex)
        {
            throw new Exception(ex.ToString());
            
        }
       
    }

Below is the code of showing the grid view in the load page:

C#

public void ShowGrid()
        {

            DataTable dtable = new DataTable("ROW");

            if (Session["ShareHolderDetails"] != null)
            {
                dtable = (DataTable)Session["ShareHolderDetails"];
            }
            else
            {
                dtable.Columns.Add(new DataColumn("NAME"));
                dtable.Columns.Add(new DataColumn("DESCRIPTION"));
                dtable.Columns.Add(new DataColumn("ASSIGNEDTO"));
                dtable.Columns.Add(new DataColumn("STARTDATE"));
                dtable.Columns.Add(new DataColumn("ENDDATE"));
            }
            gvTaskDetails.DataSource = dtable;
            gvTaskDetails.DataBind();
        }

Below is the code of the gridview RowDataBound:

C#

protected void gvTaskDetails_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            try
            {
                if (e.Row.RowType == DataControlRowType.DataRow)
                {
                    ImageButton lnkDelete = (ImageButton)e.Row.FindControl("lnkDelete");
                    lnkDelete.Attributes.Add("onclick", "javascript:return confirm('Are you sure you want to delete the selected Task Details?');");

                    TextBox txtGrdName = (TextBox)e.Row.FindControl("txtGrdName");
                    TextBox txtGrdDescription = (TextBox)e.Row.FindControl("txtGrdDescription");
                    TextBox txtStartDate = (TextBox)e.Row.FindControl("txtStartDate");
                    TextBox txtEndDate = (TextBox)e.Row.FindControl("txtEndDate");
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.ToString());
            }
        }

Below is the code of the gridview rowCommand:

C#

protected void gvTaskDetails_rowCommand(object sender, GridViewCommandEventArgs e)
        {
            String ConnectionString = @"Data Source=SAFA-PC\SQLEXPRESS;Initial Catalog=ProjectMgnmt;Integrated Security=True";
            SqlConnection SqlConn = new SqlConnection(ConnectionString);
            try
            {
                SqlConn.Open();
                int Index = Convert.ToInt32(e.CommandArgument);
                GridViewRow gRow;
                gRow = gvTaskDetails.Rows[Index];

                Label lblGrdName = (Label)gRow.FindControl("lblGrdName");
                Label lblGrdDescription = (Label)gRow.FindControl("lblGrdDescription");
                Label lblGrdAssignedTo = (Label)gRow.FindControl("lblGrdAssignedTo");
                Label lblGrdStartDate = (Label)gRow.FindControl("lblGrdStartDate");
                Label lblGrdEndDate = (Label)gRow.FindControl("lblGrdEndDate");

                TextBox txtGrdName = (TextBox)gRow.FindControl("txtGrdName");
                TextBox txtGrdDescription = (TextBox)gRow.FindControl("txtGrdDescription");
                TextBox txtGrdAssignedTo = (TextBox)gRow.FindControl("txtGrdAssignedTo");
                TextBox txtGrdStartDate = (TextBox)gRow.FindControl("txtGrdStartDate");
                TextBox txtGrdEndDate = (TextBox)gRow.FindControl("txtGrdEndDate");

                ImageButton lnkEdit = (ImageButton)gRow.FindControl("lnkEdit");
                ImageButton lnkUpdate = (ImageButton)gRow.FindControl("lnkUpdate");
                ImageButton lnkDelete = (ImageButton)gRow.FindControl("lnkDelete");

                if (e.CommandName == "EditClick")
                {
                    txtGrdName.Visible = true;
                    txtGrdDescription.Visible = true;
                    txtGrdAssignedTo.Visible = true;
                    txtGrdStartDate.Visible = true;
                    txtGrdEndDate.Visible = true;



                    lblGrdName.Visible = false;
                    lblGrdDescription.Visible = false;
                    lblGrdAssignedTo.Visible = false;
                    lblGrdStartDate.Visible = false;
                    lblGrdEndDate.Visible = false;

                    lnkUpdate.Visible = true;
                    lnkEdit.Visible = false;
                    lnkDelete.Visible = false;

                }
                if (e.CommandName == "DeleteClick")
                {
                    DataTable dTable1 = (DataTable)Session["ShareHolderDetails"];
                    dTable1.Rows.RemoveAt(Index);
                    gvTaskDetails.DataSource = dTable1;
                    gvTaskDetails.DataBind();
                    Session["ShareHolderDetails"] = dTable1;
                }

                if (e.CommandName == "UpdateClick")
                {
                    txtGrdName.Visible = false;
                    txtGrdDescription.Visible = false;
                    txtGrdAssignedTo.Visible = false;
                    txtGrdStartDate.Visible = false;
                    txtGrdEndDate.Visible = false;

                    lblGrdName.Visible = true;
                    lblGrdDescription.Visible = true;
                    lblGrdAssignedTo.Visible = true;
                    lblGrdStartDate.Visible = true;
                    lblGrdEndDate.Visible = true;

                    lnkUpdate.Visible = false;
                    lnkEdit.Visible = true;
                    lnkDelete.Visible = true;

                   DataTable dTable1 = (DataTable)Session["ShareHolderDetails"];

                    dTable1.Rows[Index]["DESCRIPTION"] = txtGrdDescription.Text;
                    dTable1.Rows[Index]["ASSIGNEDTO"] = txtGrdAssignedTo.Text;
                    
                    dTable1.Rows[Index]["STARTDATE"] = txtGrdStartDate.Text;
                    dTable1.Rows[Index]["ENDDATE"] = txtGrdEndDate.Text;
                    
                    //Bind data to the Gridview
                    gvTaskDetails.DataSource = dTable1;
                    gvTaskDetails.DataBind();

                    //Store the datatable to Session
                    Session["ShareHolderDetails"] = dTable1;

                }

            }
            catch (Exception ex)
            {
                throw new Exception(ex.ToString());
            }
            finally
            {
                SqlConn.Close();
            }
        }

Please Help..!!!
Thanks in advance

Posted 21-Jan-12 20:55pm

m_safaaaa

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Comments

OriginalGriff 22-Jan-12 3:11am

Where is that morass of code is the problem occurring?
Look at the exception detail, and it will give you a line number at the very least.
Then edit your question to tell us which line causes the problem!
Use the "Improve question" widget to edit your question and provide better information.

1 solution

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m_safaaaa · Accepted Answer · 2012-01-21T21:30:00

ohhh am i stupid??
the error is in the gridview it self; the id of labels and textboxes are wrong: the correct one is: