"Faizan Ahmed" <> wrote in message
news:%...
>
> "John Saunders" <johnwsaundersiii at hotmail.com> wrote in message
> news:...
>> "Faizan Ahmed" <> wrote in message
>> news:...
>> > Hello All,
>> >
>> > I have yet another problem,
>> > I've derived a control from Datagrid,
>> >
>> > Now in the OnInit() method i Created a button control, added it to a
>> > HtmlTable and added the HtmlTable to my Composite control's Control
>> > collection.
>> >
>> > The heirarchy is something like this
>> > CustomControl C
>> > HtmlTable T
>> > Button B
>> > i.e.
>> > H.Controls.Add(B)
>> > C.Controls.Add(T)
>> >
>> > The render method of my control is as follows
>> >
>> > Protected Overrides Sub Render(ByVal output As
>> > System.Web.UI.HtmlTextWriter)
>> >
>> >
>> >
>> > MyBase.Render(output)
>> >
>> > End Sub
>> >
>> >
>> > This statement gives an error in DataGrid.PrepareControlHierarchy()
>> > method.
>> > If i remove HtmlTable from the control collection of my control then it
>> > works fine, but then the button control in the table does not raise any
>> > events.
>> >
>> > Can any one help??Mr. Saunders?
>>
>> I wouldn't add anything to a DataGrid which it is not expecting to find
>> there. After all, how would your control feel if some derived control
>> started playing with its Controls collection?
>>
>> Instead, you could just not add T, and change your Render method to:
>>
>> Protected Overrides Sub Render(ByVal output As
> System.Web.UI.HtmlTextWriter)
>> T.RenderControl(output)
>> MyBase.Render(output)
>> End Sub
>>
>> If you need the table to come after the DataGrid, you can put the
>> T.RenderControl after the MyBase.Render.
>>
>> John Saunders
>>
>>
>>
> But if i implement it this way i wont get any events raised by my control
> T(or its child controls B), because their viewstate wont be mantained by
> the
> Grid. I think this is a problem many people must've come across but i m
> not
> sure why there is no solution available for it, may be there is a
> straightforward way of doin such a think and i m moving in a wrong
> direction.
> I've been able to identify the cause of my problem; the
> PrepareControlHeirarchy() function of the DataGrid (which applies styles
> on
> the control)expects all of the new controls to be added at the end of
> controls collection.
It may be that you will have to stop inheriting from DataGrid and instead
create a composite control which contains both the DataGrid and your Table.
Both the DataGrid and the Table would be in the Controls collection of your
control, thus ViewState will be maintained.
John Saunders
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