[Gambas-user] Huge data in gridview documentation wiki does not explain how

[PICCORO McKAY Lenz]

umm so then as you said, the rs number 30000 does not load until i get down
the gridview to the row 30000! ?

if this the case, how can i implement a search input that retrieve data
when i put strings!?

Lenz McKAY Gerardo (PICCORO)
http://qgqlochekone.blogspot.com

2017-05-16 17:10 GMT-04:00 Tobias Boege <taboege at ...626...>:

> On Tue, 16 May 2017, PICCORO McKAY Lenz wrote:
> > In gambas wiki documentation said:
> >
> > You can fill the grid explicitly, or implement the Data
> > <http://gambaswiki.org/wiki/comp/gb.qt4/gridview/.data> event to display
> > the grid contents on demand.
> >
> > You should use the last method if you have a lot of rows to display. The
> > control can handle millions of lines gracefully.
> >
> > but i try to set gridview.data event and set GridView1*.*Data*.*Text but
> > when comes the object said it null (Data) ...
> >
> > its there any example to load? i have a CSV and also a table db.. please
> > its the documentation wrong?
> >
>
> It's not. This method is so fast and easy on memory because you load the
> GridView contents *on demand*. Read the text carefully: it tells you that
> the GridView will raise the Data *event* (not the Data property; it even
> links to the Data event documentation [1] which is IMHO comprehensive
> enough) when it needs the contents of certain cells.
>
> So, when the GridView control detects that it should display a certain
> cell,
> identified by a Row and a Column number, it will raise the GridView_Data
> event with just these Row and Column arguments. *During* such a Data event,
> the GridView.Data property will contain a valid object and you have to
> retrieve the cell data somehow (from your CSV file or database or ...) and
> store it inside the GridView.Data property. You may only use the Data
> property during the Data event.
>
> If you still need an example, the IDE source code has some. You can also
> look at the implementation of the ListBox control in gb.gui.base. It uses
> the Data event of a GridView internally, too. (Who would've thought that
> the ListBox is also just a GridView in disguise?)
>
> Regards,
> Tobi
>
> [1] http://gambaswiki.org/wiki/comp/gb.qt4/gridview/.data
>
> --
> "There's an old saying: Don't change anything... ever!" -- Mr. Monk
>
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