Refilling dataset without changing context

[John]

Hi

I have a winform db app that is "bound" to a dataset...via data adpater,
binding source and all that. As this is a multi-user app I need to refill
dataset from time to time so the newest data is available for user to view.
My problem is that I

a) do not wish the app to become unresponsive while re-fill is being
performed so need to do it as background task if possible.

b) do not want the record context to change for user so user does not notice
any disruption.

My question is, are the above possible? If so, how? If not what is an
alternate strategy?

Thanks

Regards

[Jack Jackson]

On Mon, 4 Feb 2008 01:53:48 -0000, "John" <Jo**@nospam.infovis.co.uk>
wrote:

>Hi

I have a winform db app that is "bound" to a dataset...via data adpater,
binding source and all that. As this is a multi-user app I need to refill
dataset from time to time so the newest data is available for user to view.
My problem is that I

a) do not wish the app to become unresponsive while re-fill is being
performed so need to do it as background task if possible.

b) do not want the record context to change for user so user does not notice
any disruption.

My question is, are the above possible? If so, how? If not what is an
alternate strategy?

No matter how you refill the dataset, while it is refilling the user
will see effects in the bound controls.

It might be better if you have two datasets. Bind one to the
controls, then refill the other. When it is refilled switch the
binding.

I have no experience with trying to fill a dataset asynchronously and
don't know if it is possible.

[John]

This must be a very common scenarios.What do other people do to achieve
this?

Thanks

Regards

"Jack Jackson" <jj******@cinnovations.netwrote in message
news:ue********************************@4ax.com...

On Mon, 4 Feb 2008 01:53:48 -0000, "John" <Jo**@nospam.infovis.co.uk>
wrote:

>>Hi

I have a winform db app that is "bound" to a dataset...via data adpater,
binding source and all that. As this is a multi-user app I need to refill
dataset from time to time so the newest data is available for user to
view.
My problem is that I

a) do not wish the app to become unresponsive while re-fill is being
performed so need to do it as background task if possible.

b) do not want the record context to change for user so user does not
notice
any disruption.

My question is, are the above possible? If so, how? If not what is an
alternate strategy?

No matter how you refill the dataset, while it is refilling the user
will see effects in the bound controls.

It might be better if you have two datasets. Bind one to the
controls, then refill the other. When it is refilled switch the
binding.

I have no experience with trying to fill a dataset asynchronously and
don't know if it is possible.

[Jack Jackson]

I rarely have a large number of records in a datatable, so refreshing
doesn't take a noticeable amount of time.

On Mon, 4 Feb 2008 14:44:30 -0000, "John" <Jo**@nospam.infovis.co.uk>
wrote:

>This must be a very common scenarios.What do other people do to achieve
this?

Thanks

Regards

"Jack Jackson" <jj******@cinnovations.netwrote in message
news:ue********************************@4ax.com.. .

>On Mon, 4 Feb 2008 01:53:48 -0000, "John" <Jo**@nospam.infovis.co.uk>
wrote:

>>>Hi

I have a winform db app that is "bound" to a dataset...via data adpater,
binding source and all that. As this is a multi-user app I need to refill
dataset from time to time so the newest data is available for user to
view.
My problem is that I

a) do not wish the app to become unresponsive while re-fill is being
performed so need to do it as background task if possible.

b) do not want the record context to change for user so user does not
notice
any disruption.

My question is, are the above possible? If so, how? If not what is an
alternate strategy?

No matter how you refill the dataset, while it is refilling the user
will see effects in the bound controls.

It might be better if you have two datasets. Bind one to the
controls, then refill the other. When it is refilled switch the
binding.

I have no experience with trying to fill a dataset asynchronously and
don't know if it is possible.

[John]

Hi Andrej

Thanks. Would it have any effect on user experience in that user's editing
at the time of dataset population will be lost for example?

Any idea if I can populate dataset as a background task without problem?

Thank again.

Regards
"Andrej Tozon" <an**********@gmail.comwrote in message
news:f8**********************************@f10g2000 hsf.googlegroups.com...

Hi John,

try calling your BindingSource's SuspendBinding() method before re-
populating dataset, and ResumeBinding() after it's done.

Andrej

[Gregg Walker]

Just one question; if the user is in the middle of an edit is that

information not lost when UISet has been updated from
the BGSet?

Basically what we do is throw away the BGSet whenever the user is in the
middle of editing.

So I'll have some code that detects when an edit is started and finished and
update some global bool that will let the UI thread delegate know not to do
anything with the BGSet when an edit is in progress. The UISet will only be
updated when an edit is not in progress.

Also in the case where the process of rebinding the UISet to controls may a
short time you may conversely want to prevent editing while the delegate
method is actually rebinding the UISet.

Another way to handle this if you can't afford to ignore new BGSets is to
push new BGSets onto a stack when the delegate method is called and an edit
is in progress. Once any edit is finished you can check the stack for
entries and pop the last BGSet and rebind when one exists.

HTH
--
Gregg Walker

[John]

Thanks. Makes perfect sense.

Regards
"Gregg Walker" <xy***@newsgroup.nospamwrote in message
news:%2****************@TK2MSFTNGP05.phx.gbl...

>Just one question; if the user is in the middle of an edit is that
information not lost when UISet has been updated from
the BGSet?

Basically what we do is throw away the BGSet whenever the user is in the
middle of editing.

So I'll have some code that detects when an edit is started and finished
and update some global bool that will let the UI thread delegate know not
to do anything with the BGSet when an edit is in progress. The UISet will
only be updated when an edit is not in progress.

Also in the case where the process of rebinding the UISet to controls may
a short time you may conversely want to prevent editing while the delegate
method is actually rebinding the UISet.

Another way to handle this if you can't afford to ignore new BGSets is to
push new BGSets onto a stack when the delegate method is called and an
edit is in progress. Once any edit is finished you can check the stack
for entries and pop the last BGSet and rebind when one exists.

HTH
--
Gregg Walker