Web derived controls in VS2005 designer view

[postings]

Hi

I'm more or less desperate here, I've posted this in a few forums now
over the months and got absolutely no response. It would be very much
appreciate that you could help in any way here... So take pity

I have a control derived from a drop down list written in VB.NET
(ASP.NET 2.0) that dynamically displays listitems retrieved from an SQL
server database. My code works fine but when I go to designer view in
Visual Studio 2005 it renders a gray box displaying: "Error Creating
Control - MyDropDownList, object reference not set to an instance of an
object". Note the drop down list works perfectly when being displayed
in IE.

If I remove my code retrieving the values from SQL server and put in
static values like this:
----------------------------------------------------
Me.Items.Add(New ListItem("Select a Value", "0"))
Me.Items.Add(New ListItem("Test", "1"))
----------------------------------------------------


....the drop down list will render in both the designer and IE. So I am
assuming that the VS2005 designer view will not render dynamic
listitems, but will render static listitems from dropdownlists.

In order to solve this problem I've looked at using:
Protected Overrides Sub Render(ByVal writer As
System.Web.UI.HtmlTextWriter)

....to see if I can force rendering in the design view but no joy at
all, so my approach isn't working here.

I don't really care if the designer renders the exact values from the
database, a couple of dummy values will do if necessary. I just want to
see the control is designer view.

So please - any words of wisdom!

Many thanks indeed...

Alex

 

[Steve C. Orr [MVP, MCSD]]

IF Me.DesignMode = True THEN
'Use Static Values
Me.Items.Add(New ListItem("Select a Value", "0"))
Me.Items.Add(New ListItem("Test", "1"))
ELSE
'get from SQL Server
END IF

 

[ovalsquare]

Alex,

Did this solve it for you? As I've got the same problem and Steve's
solution does not fix the issue (still get the error in design view).

Ted

 

[postings]

Hi Oval

No it didn't unfortunately (thanks for trying Steve).
I see the logic in the code, and I can't see why it doesn't work.
Please let me know if you get any further than I did (is this a VS2005
IDE bug?).

Thanks

Alex

 

[Alex Shirley]

Hi

Was there ever a solution to this, is designmode broken?

Many thanks!

Alex

 

[postings]

Anybody? (one last go before I fizzle out

Thanks

Alex