Gridview deletion problem

18 Jan 2007 4:59 PM

Flomo Togba Kwele

I created a form, a datasource (Product table from AdventureWorks)
from the Data Sources tab, and dragged the Product table from the Data
Source tab to the form's designer surface.

This created a dataset, bindingsource, tableadapter and
bindingnavigator.

I placed the following code in the click event of the delete button on
the bindingnavigator:

      Me.Validate()
      Me.ProductBindingSource.EndEdit()
      Me.ProductTableAdapter.Update(Me.AdventureWorksDataSet.Product)

When running the app, I select a row and click the delete button on
the navigator. It disappears. However, when I exit the app and
re-enter, the row is still there.

As another test, if I select the row again, and click the delete
button, and click it once more, the row is actually deleted from the
database.

In debug I place a stop after the Validate method above. The
underlying dataset shows false for HasChanges after the first click of
the delete button and the selected row shows Unchanged for its
RowState.

However, after the 2nd click of the delete button, the dataset shows
true for HasChanges and Deleted for the RowState associated with the
row.

What is wrong with my code?

Thanks

24 Jan 2007 2:01 PM

Flomo Togba Kwele

Wen Yuan,

In working with the code further, I need some advice on an appropriate
approach.

Given that the following code works:

Me.ProductBindingSource.RemoveCurrent ()
Me.Validate()
Me.ProductBindingSource.EndEdit()
Me.ProductTableAdapter.Update(Me.AdventureWorksDataSet.Product)

I can get an error from the update method on a referential constraint
- the row is used somewhere else and cannot be deleted.

I can wrap the update in a try-catch block so that I retain control
over the process, but the item has already been removed from the grid
in the first statement, the RemoveCurrent method. The user sees the
error message (I use an error provider in the try-catch block) that
it can't be deleted, but the item is visually deleted.

What approach can I use to avoid this?

Thanks, Flomo

On Thu, 18 Jan 2007 08:59:22 -0800, Flomo Togba Kwele
<flomo@community.nospam> wrote:

Show quote

>I created a form, a datasource (Product table from AdventureWorks)
>from the Data Sources tab, and dragged the Product table from the Data
>Source tab to the form's designer surface.
>
>This created a dataset, bindingsource, tableadapter and
>bindingnavigator.
>
>I placed the following code in the click event of the delete button on
>the bindingnavigator:
>
>      Me.Validate()
>      Me.ProductBindingSource.EndEdit()
>      Me.ProductTableAdapter.Update(Me.AdventureWorksDataSet.Product)
>
>When running the app, I select a row and click the delete button on
>the navigator. It disappears. However, when I exit the app and
>re-enter, the row is still there.
>
>As another test, if I select the row again, and click the delete
>button, and click it once more, the row is actually deleted from the
>database.
>
>In debug I place a stop after the Validate method above. The
>underlying dataset shows false for HasChanges after the first click of
>the delete button and the selected row shows Unchanged for its
>RowState.
>
>However, after the 2nd click of the delete button, the dataset shows
>true for HasChanges and Deleted for the RowState associated with the
>row.
>
>What is wrong with my code?
>
>Thanks

25 Jan 2007 7:30 AM

WenYuan Wang

Hi Flomo,
Thanks for you reply.

Each bindingSource is related to a datatable/dataset. After
bindingsource.removecurrent() method has been called, the row in the
datatable will be flagged as "deleted". If we want to cancel this transact,
we can call rejectChanges() method.

For example; CType([Me.BindingSource.DataSource],
System.Data.DataSet).RejectChanges()

Could you add this statement into try-catch block to check whether or not
this method works for you.
I'm very glad to work with you. Please reply if you have any further
problem or concerns on this.

Hope this helps.
Have a great day!
Wen Yuan

25 Jan 2007 11:11 PM

Flomo Togba Kwele

And if it's not a dataset but a custom object?

On Thu, 25 Jan 2007 07:30:03 GMT, v-wyw***@online.microsoft.com
(WenYuan Wang) wrote:

Show quote

>Hi Flomo,
>Thanks for you reply.
>
>Each bindingSource is related to a datatable/dataset. After
>bindingsource.removecurrent() method has been called, the row in the
>datatable will be flagged as "deleted". If we want to cancel this transact,
>we can call rejectChanges() method.
>
>For example; CType([Me.BindingSource.DataSource],
>System.Data.DataSet).RejectChanges()
>
>Could you add this statement into try-catch block to check whether or not
>this method works for you.
>I'm very glad to work with you. Please reply if you have any further
>problem or concerns on this.
>
>Hope this helps.
>Have a great day!
>Wen Yuan

30 Jan 2007 12:15 PM

WenYuan Wang

Hi Flomo,

I Just want to check if the issue has been resolved? If it still persists,
please don't hesitate to update here.
We'll go on to assist you on it. Thanks.

Best Regards,
Wen Yuan

25 Feb 2007 10:40 PM

Alsan Wong

Hi,

I'm wondering why there's no somethings like ItemRemoved event?

""WenYuan Wang"" wrote:

Show quote

> Hi Flomo,
>
> I Just want to check if the issue has been resolved? If it still persists,
> please don't hesitate to update here.
> We'll go on to assist you on it. Thanks.
>
> Best Regards,
> Wen Yuan
>
>