Grid view Dropdown list data binding error

Question

Am using the below code to bind the dropdown data from another table. And also refer that control name using rowindex. But it always return null.And also return the error message.

  `Object reference not set to an instance of an object.`

Am using the two method, but both return the control name null

First code:

 protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            Control ctrl = e.Row.FindControl("DDL_STATUS_FT"); //It always return null
            if (ctrl != null)
            {
                DropDownList dd = ctrl as DropDownList;
                DataSet7TableAdapters.sp_getall_trv_masterTableAdapter TA = new DataSet7TableAdapters.sp_getall_trv_masterTableAdapter();
                DataSet7.sp_getall_trv_masterDataTable DS = TA.GetData();
                dd.DataTextField = "fld_TName";
                dd.DataValueField = "fld_id";
                dd.DataSource = DS;
                dd.DataBind();
            }

        }

    }

Second :

 In databind function



if (DS.Rows.Count > 0)
    {
        GridView2.DataSource = DS;
        GridView2.DataBind();

    foreach (GridViewRow grdRow in GridView2.Rows)
    {
        DataSet7TableAdapters.sp_getall_trv_masterTableAdapter TA1 = new DataSet7TableAdapters.sp_getall_trv_masterTableAdapter();
        DataSet7.sp_getall_trv_masterDataTable DS1 = TA1.GetData();
        // Nested DropDownList Control reference is passed to the DrdList object. This will allow you access the properties of dropdownlist placed inside the GridView Template column.  
        DropDownList drdList = (DropDownList)(GridView2.Rows[grdRow.RowIndex].Cells[4].FindControl("DDL_STATUS_FT"));//It always return null

        // DataBinding of nested DropDownList Control for each row of GridView Control.  
        drdList.DataSource = DS1;
        drdList.DataValueField = "fld_id";
        drdList.DataTextField = "fld_TName";
        drdList.DataBind();
    } 
}

Please help me to do this..

   <asp:TemplateField ItemStyle-Width="100px" HeaderText="TYPE">
                        <ItemTemplate>
                            <asp:DropDownList ID="DDL_STATUS" runat="server" AutoPostBack="true" Enabled="false" >
                            </asp:DropDownList>
                        </ItemTemplate>
                        <EditItemTemplate>
                            <asp:DropDownList ID="DDL_edit_STATUS" runat="server" AutoPostBack="true" SelectedValue='<%# Eval("fld_Type") %>'>
                            </asp:DropDownList>
                        </EditItemTemplate>
                        <FooterTemplate>
                            <asp:DropDownList ID="DDL_STATUS_FT" runat="server" AutoPostBack="true">
                            </asp:DropDownList>
                        </FooterTemplate>
                    </asp:TemplateField>

where is your drop downlist in aspx code DDL_STATUS_FT ?

Anant Dabhi
– Anant Dabhi

2012-09-25 07:12:52 +00:00
Commented Sep 25, 2012 at 7:12 — Anant Dabhi
– Anant Dabhi, Commented Sep 25, 2012 at 7:12

Amol Kolekar · Accepted Answer · 2012-09-25 07:35:32Z

1

The DropDown "DDL_STATUS_FT" is in Footer Template..You must check it as follow..

if(e.Row.RowType == DataControlRowType.Footer)
{
  DropDownList ctrl =(DropDownList)e.Row.Cells[CellIndex].FindControl("DDL_STATUS_FT"); 
}

answered Sep 25, 2012 at 7:35

Amol Kolekar

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5 Comments

romi Over a year ago

It's working fine..But i have one doubt i want to add this in itemtemplate also

Amol Kolekar Over a year ago

DataControlRowType.DataRow is used to get Controls in ItemTemplate..You cannot find "DDL_STATUS_FT" if you are checking RowType as Datarow...

romi Over a year ago

yes i find the items for all row. But i want to include the gridview row edit event.. protected void EditGrade(object sender, GridViewEditEventArgs e) { GridView2.EditIndex = e.NewEditIndex; BindData1(); } //Error in Bind datasection.

romi Over a year ago

private void BindData1()     {         DataSet7TableAdapters.sp_getall_trv_config_masterTableAdapter TA = new DataSet7TableAdapters.sp_getall_trv_config_masterTableAdapter();         DataSet7.sp_getall_trv_config_masterDataTable DS = TA.GetData();         if (DS.Rows.Count > 0)         {             GridView2.DataSource = DS;             GridView2.DataBind();           }}

Amol Kolekar Over a year ago

@romi...this question was regarding object reference error..and i think it has been solved now...if you have any further issues or queries you can ask them creating new Questions.Formatting is not applied in comment area..so it is difficult to understand what u need.and also if you create new questions chances that u will get perfect solutions will be higher as everyone will be able to see it and help you out...

Sanjay Gupta · Accepted Answer · 2012-09-25 07:12:52Z

0

Try to find your control by cell and cellIndex like...

Control ctrl = e.Row.Cells[yourCellIndex].FindControl("DDL_STATUS_FT");

answered Sep 25, 2012 at 7:12

Sanjay Gupta

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Comments

Anant Dabhi · Accepted Answer · 2012-09-25 07:17:54Z

0

EDITED2

you must have dropdownlist in aspx code in gridview item-template

you are finding using e.row.findcontrol without declaring it so abusively it return null

so, fist add dropdownlist into your gridview here is a sample of your dropdownlist

   <asp:TemplateField ItemStyle-Width="30px" HeaderText="DDL_STATUS_FT">
                        <ItemTemplate>
                            <asp:Dropdownlist ID="DDL_STATUS_FT" runat="server" />
                        </ItemTemplate>
                    </asp:TemplateField>

if you got null ctrl Control ctrl = e.Row.FindControl("DDL_STATUS_FT"); //It always return null

then make sure in your aspx code DDL_STATUS_FT Control is runat="server"

edited Sep 25, 2012 at 7:17

answered Sep 25, 2012 at 6:47

Anant Dabhi

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3 Comments

romi Over a year ago

DS not dataset, It's a datatable

romi Over a year ago

if (ctrl != null) value always return null value

romi Over a year ago

But My dropdown id is present in the gridview

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