Binding dropdownlist inside gridview edititemtemplate

Question

I'm not able to bind my dropdownlist present in edititem template . I am getting null reference when i try to access it.

My design:

<asp:TemplateField HeaderText ="Category">
    <ItemTemplate >
    <asp:Label ID="drpcategory" Text ='<%#Bind("category") %>' runat ="server" />
    </ItemTemplate>
    <EditItemTemplate>
        <asp:DropDownList ID="drpcategory1"  AppendDataBoundItems="True" runat="server" >
        </asp:DropDownList>
    </EditItemTemplate>
</asp:TemplateField>

My code behind:

protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
{
    gv_table1.EditIndex = e.NewEditIndex;
    DropDownList drpcategory1 = ((DropDownList)gv_table1.Rows[e.NewEditIndex].Cells[8].FindControl("drpcategory1"));
    //BindDropDown(drpcategory1);
    dt = con.GetData("Select category_name from category");

    String str = gv_table1.Rows[e.NewEditIndex].FindControl("drpcategory1").GetType().ToString();
    //((DropDownList)gv_table1.Rows[e.NewEditIndex].Cells[8].FindControl("drpcategory1")).DataSource = dt;
    drpcategory1.DataSource = dt;
    drpcategory1.DataTextField = "category_name";
    drpcategory1.DataValueField = "category_name";
    drpcategory1.DataBind();

    this.setgrid();
}

I've tried looking on the net and tried many things in vain. I am new to asp. Thanks in advance. I would like the dropdown to be bound only when user enters edit mode.

What is gv_table1 ? I think that might be the issue. Pls check — kbvishnu, Sep 03 '12 at 11:52
Don't use `Cells[8].FindControl("drpcategory1")` but `row.FindControl("drpcategory1")` since the `NamingContainer` is the row not the cell. Your way is more error-prone. — Tim Schmelter, Sep 03 '12 at 11:54
I am using row.findcontrol only .I have also used cells.I tried both but not getting desired result. — Prashanth, Sep 03 '12 at 12:08
@TimSchmelter `row.FindControl` [just doesn't work for me... no matter what I tried.](http://stackoverflow.com/q/24771214/1389394) — bonCodigo, Jul 16 '14 at 05:45

score 32 · Accepted Answer · edited May 07 '21 at 00:31

32

Code Behind: Tested Code and also set dropdown-list selected value on edit mode

protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        if ((e.Row.RowState & DataControlRowState.Edit) > 0)
        {
            DropDownList ddList= (DropDownList)e.Row.FindControl("drpcategory1");
            //bind dropdown-list
            DataTable dt = con.GetData("Select category_name from category");
            ddList.DataSource = dt;
            ddList.DataTextField = "category_name";
            ddList.DataValueField = "category_name";
            ddList.DataBind();
            
            DataRowView dr = e.Row.DataItem as DataRowView;
            //ddList.SelectedItem.Text = dr["category_name"].ToString();
            ddList.SelectedValue = dr["category_name"].ToString();
        }
    }
}
    
protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
{
    gv.EditIndex = e.NewEditIndex;
    gridviewBind();// your gridview binding function
}

edited May 07 '21 at 00:31

Martijn Pieters

1,048,767
296
4,058
3,343

answered Sep 04 '12 at 07:34

Satinder singh

10,100
16
60
102

Got the desired thing man.But DataRowView dr = e.Row.DataItem as DataRowView; ddList.SelectedItem.Text = dr["category_name"].ToString();these two lines showed error removing these two lines i executed and got the output dude.Thanks bro – Prashanth Sep 04 '12 at 09:09
@Prashanth: good if it help , well can u paste the error msg u getting for those lines. – Satinder singh Sep 04 '12 at 09:32
Dude i corrected that error it was just a naming problem but now Bro all is well but now the first element in the dropdownlist is getting rewritten to the label value man when in edit mode (i.e)I have repetition of one element and also losing another.Hope you understand what i mean. – Prashanth Sep 04 '12 at 10:05
@Prashanth: Bro check my updated answer have fixed that issue, also Mark upvote if its helps :) – Satinder singh Sep 04 '12 at 11:02
1

:ya man i also fixed it just now dude.I was about to update your answer man but you updated it dude thanks man. – Prashanth Sep 04 '12 at 12:04
Can you post the `Row_Updating()` for the same solution? For Updating, that's where we capture the selected item of the dropdown, don't we? – bonCodigo Jul 15 '14 at 09:26
this is exactly what I want – Pramesh Aug 12 '15 at 21:18

score 3 · Answer 2 · answered Aug 27 '18 at 01:37

I do it like this. In which, Name and Id are two fields of Company object:

HTML Code:

<asp:TemplateField HeaderText="Công ty">
    <EditItemTemplate>
        <asp:DropDownList ID="ddlCompanyEdit" DataSource="<%# PopulateddlCompanyEdit() %>" DataValueField="Id" DataTextField="Name" runat="server"></asp:DropDownList>
    </EditItemTemplate>
    <ItemTemplate>
        <asp:Label ID="lbCompany" runat="server" Text='<%#Bind("Company") %>'></asp:Label>
    </ItemTemplate>
</asp:TemplateField>

C# code behind:

protected IEnumerable<Company> PopulateddlCompanyEdit()
{
    using (var bkDb = new BrickKilnDb())
    {
        return bkDb.Companies.ToList();
    }
}

score 2 · Answer 3 · edited Aug 07 '13 at 04:47

protected void gvProject_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        try
        {
            string Active = "";
            if (e.Row.DataItem != null)
            { 
                if ((e.Row.RowState & DataControlRowState.Edit) > 0)
                {
                    Label lblEditActive = (Label)e.Row.FindControl("lblUP_ET_ActiveStatus");
                    if (lblEditActive.Text != string.Empty)
                    {
                        Active = lblEditActive.Text.Trim();
                    }

                    DropDownList ddlActive = (DropDownList)e.Row.FindControl("ddlUP_ET_ActiveStatus");
                    ddlActive.Items.Clear();
                    ddlActive.Items.Add("True");
                    ddlActive.Items.Add("False"); 
                    ddlActive.DataBind(); 
                    ddlActive.Items.FindByText(Active).Selected = true;
                }
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

score 0 · Answer 4 · answered Sep 03 '12 at 11:53

0

The event RowEditing occurs just before a row is edited.

You should use the RowDataBound event instead.

protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
{
   if (gv.EditIndex == e.Row.RowIndex && 
       e.Row.RowType==DataControlRowType.DataRow) 
   {       
       DropDownList drpcategory1 = (DropDownList)e.Row.FindControl("drpcategory1"); 
       //bind the control
   }
}

answered Sep 03 '12 at 11:53

nunespascal

17,584
2
43
46

Drpcategory1 value is null only when i put breakpoint and check the value.I did as per you told. – Prashanth Sep 03 '12 at 12:06

score 0 · Answer 5 · answered Sep 04 '12 at 05:52

You have to use RowDataBound event to bind the dropdown control for edited row. Please use below method in RowDataBound event.

        protected void gv_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowState == DataControlRowState.Edit)
        {
            DropDownList drpcategory1 = (DropDownList)e.Row.FindControl("drpcategory1");
            DataTable dt = con.GetData("Select category_name from category");
            drpcategory1.DataSource = dt;
            drpcategory1.DataTextField = "category_name";
            drpcategory1.DataValueField = "category_name";
            drpcategory1.DataBind();
        }
    }

Hope this will help you.

Binding dropdownlist inside gridview edititemtemplate

5 Answers5

Linked

Related