Override add on bindinglist

[Ste]

Good morning,
I have a bindinglist of my custom objects and need to check, before
adding items, if an item exists in list and then cancel inserting.

I have tried to create an object that inherits from
bindinglist<myc ustomobjectbut I cannot override Add method.

This because this bindinglist is a datasource for a datagrid and need to
avoid to insert duplicated instances.

Thanks.
Stefano.

[Pavel Minaev]

Re: Override add on bindinglist

On Jul 22, 6:24 pm, Ste <sceru...@svilu pso.itwrote:

Good morning,
I have a bindinglist of my custom objects and need to check, before
adding items, if an item exists in list and then cancel inserting.
>
I have tried to create an object that inherits from
bindinglist<myc ustomobjectbut I cannot override Add method.

You shouldn't override Add, you should override the protected
InsertItem method. It will be called for any operation that inserts a
new item into the list, be it Add or Insert.

[Ste]

Re: Override add on bindinglist

Ok, but now I have tried to override EndNew method to find in the
innerlist if item was inserted (because only when I commit I have all
data to use for search) and then cancel it using CancelNew. The problem
is that ItemIndex parameter is alwais -1.

Thank you.
Stefano.

Pavel Minaev ha scritto:

On Jul 22, 6:24 pm, Ste <sceru...@svilu pso.itwrote:

>Good morning,
>I have a bindinglist of my custom objects and need to check, before
>adding items, if an item exists in list and then cancel inserting.
>>
>I have tried to create an object that inherits from
>bindinglist<my customobjectbut I cannot override Add method.

>
You shouldn't override Add, you should override the protected
InsertItem method. It will be called for any operation that inserts a
new item into the list, be it Add or Insert.