asp:repeater and hashtable - also in languages.csharp

[Joe Fawcett]

Sorry about the multi post, I thought I'd sent to both groups simultaneously but
somehow it failed to find this one the first time.

I'm having a problem binding an asp:repeater control to a Hashtable. Originally
my code was:

<asp:Repeater id="rptFamily" runat="server" DataSource="<%# family %>">
<ItemTemplate>
<%# DataBinder.Eval(Container.DataItem, "Key") %> =
<%# DataBinder.Eval(Container.DataItem, "Value") %>
</ItemTemplate>
</asp:Repeater>

which was bound to a Hashtable and all works fine. I then started reading that
Databind.Eval was an overkill, I could just use:

<asp:Repeater id="rptFamily" runat="server" DataSource="<%# family %>">
<ItemTemplate>
<%# Container.DataItem.Key %> =
<%# Container.DataItem.Value %>
</ItemTemplate>
</asp:Repeater>

but although I can build the site when accessing the page I get an error that :

'object' does not contain a definition for 'Key'

pointing to the first changed line. I've found lots of examples on the Web
showing this second version, are they all perhaps from a beta version or is it
something else?

Thanks

 

[Karl Seguin]

Joe:

Try:

<%# ((DictionaryEntry)Container.DataItem).Key %>
<%# ((DictionaryEntry)Container.DataItem).Value%>

Container.DataItem is of type object
object doesn't container a "key" or "value" property

You need to explicitely cast it to the underlying type that is being bound.
When you are binding to a DataSet/DataTable/DataView, Container.DataItem is
always a "DataRowView"...

DataBinder.Eval does have performance implications, but on the flip side it
lets you change the underlying datasource implementation without breaking
your code...ie, using DataBinder.Eval you could switch to a dataset, and as
long as it had a property named "key" and "value" everything would continue
to work...

Karl

 

[Joe Fawcett]

Joe:

Try:

<%# ((DictionaryEntry)Container.DataItem).Key %>
<%# ((DictionaryEntry)Container.DataItem).Value%>

Container.DataItem is of type object
object doesn't container a "key" or "value" property

You need to explicitely cast it to the underlying type that is being bound.
When you are binding to a DataSet/DataTable/DataView, Container.DataItem is
always a "DataRowView"...

DataBinder.Eval does have performance implications, but on the flip side it
lets you change the underlying datasource implementation without breaking
your code...ie, using DataBinder.Eval you could switch to a dataset, and as
long as it had a property named "key" and "value" everything would continue
to work...

Karl
--
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http://www.openmymind.net/ - New and Improved (yes, the popup is annoying)
http://www.openmymind.net/faq.aspx - unofficial newsgroup FAQ (more to
come!)

Thanks, it works. So does that mean that the example code I've seen, using a
HashTable, was wrong?

 

[Karl Seguin]

Since I haven't seen the example code, I can't really say...

Karl