Hi,

i defined a dropdownlist in an EditTemplate of a detailsview like this:

<EditItemTemplate>
<asp:DropDownList ID="drop1" runat="server"></asp:DropDownList>
</EditItemTemplate>

I want to populate it in code-behind; i tried this:

Protected Sub DetailsView1_ItemCreated(ByVal sender As Object, ByVal e As 
System.EventArgs) Handles DetailsView1.ItemCreated
        If DataControlRowState.Edit Then    'only in edit mode
            If DataControlRowType.DataRow Then    'only datarow
                Dim dd1 As DropDownList
                Dim z1 As ListItem
                Dim i As Integer
                dd1 = CType(DetailsView1.Rows(5).FindControl("drop1"), 
DropDownList)
                For i = 0 To 20
                z1 = New ListItem(i, i)
                dd1.Items.Add(z1)
                Next
            End If
        End If
    End Sub

But i get the error:"Object reference not set to an instance of an object"
at line:  dd1.Items.Add(z1)

Thanks for help
Jan

Jan,

Seems your dropdownlist is not plaved in the 5th row (remember in this case 
rows are numbered starting from zero). Anyway, you don't have to use 
row(index), just try DetailsView1.FindControl("drop1"). If this doesn't work, 
try to debug this line of the code and find the control location (ie. by 
traversing the control tree within the with Quick View window).

HTH
-- 
Milosz


"Jan" wrote:


> Hi,
> 
> i defined a dropdownlist in an EditTemplate of a detailsview like this:
> 
> <EditItemTemplate>
> <asp:DropDownList ID="drop1" runat="server"></asp:DropDownList>
> </EditItemTemplate>
> 
> I want to populate it in code-behind; i tried this:
> 
> Protected Sub DetailsView1_ItemCreated(ByVal sender As Object, ByVal e As 
> System.EventArgs) Handles DetailsView1.ItemCreated
>         If DataControlRowState.Edit Then    'only in edit mode
>             If DataControlRowType.DataRow Then    'only datarow
>                 Dim dd1 As DropDownList
>                 Dim z1 As ListItem
>                 Dim i As Integer
>                 dd1 = CType(DetailsView1.Rows(5).FindControl("drop1"), 
> DropDownList)
>                 For i = 0 To 20
>                 z1 = New ListItem(i, i)
>                 dd1.Items.Add(z1)
>                 Next
>             End If
>         End If
>     End Sub
> 
> But i get the error:"Object reference not set to an instance of an object"
> at line:  dd1.Items.Add(z1)
> 
> Thanks for help
> Jan 
> 
> 
> 

Ji Milosz, thanks for replying.

I tried DetailsView1.FindControl("drop1") but still same error ...
I use VWD (Visual web dev.) and i don't understand what you mean with:"try 
to debug this line of the code and find the control location (ie. by 
traversing the control tree within the with Quick View window)."

I get the error even in normal mode. Maybe are these lines not correct:
If DataControlRowState.Edit Then

If DataControlRowType.DataRow Then



......


"Milosz Skalecki [MCAD]"  schreef in bericht 
news:7CD90115-0DE6-4E7C-8916-EC67565E2A78@microsoft.com...

> Jan,
>
> Seems your dropdownlist is not plaved in the 5th row (remember in this 
> case
> rows are numbered starting from zero). Anyway, you don't have to use
> row(index), just try DetailsView1.FindControl("drop1"). If this doesn't 
> work,
> try to debug this line of the code and find the control location (ie. by
> traversing the control tree within the with Quick View window).
>
> HTH
> -- 
> Milosz
>
>
> "Jan" wrote:
>
>> Hi,
>>
>> i defined a dropdownlist in an EditTemplate of a detailsview like this:
>>
>> <EditItemTemplate>
>> <asp:DropDownList ID="drop1" runat="server"></asp:DropDownList>
>> </EditItemTemplate>
>>
>> I want to populate it in code-behind; i tried this:
>>
>> Protected Sub DetailsView1_ItemCreated(ByVal sender As Object, ByVal e As
>> System.EventArgs) Handles DetailsView1.ItemCreated
>>         If DataControlRowState.Edit Then    'only in edit mode
>>             If DataControlRowType.DataRow Then    'only datarow
>>                 Dim dd1 As DropDownList
>>                 Dim z1 As ListItem
>>                 Dim i As Integer
>>                 dd1 = CType(DetailsView1.Rows(5).FindControl("drop1"),
>> DropDownList)
>>                 For i = 0 To 20
>>                 z1 = New ListItem(i, i)
>>                 dd1.Items.Add(z1)
>>                 Next
>>             End If
>>         End If
>>     End Sub
>>
>> But i get the error:"Object reference not set to an instance of an 
>> object"
>> at line:  dd1.Items.Add(z1)
>>
>> Thanks for help
>> Jan
>>
>>
>>