3.5 extension methods give you the OfType<T> extension on IEnumerable, so you can now do:
foreach (ReportA item in reports.OfType<ReportA>()) Otherwise, you'd have to do the cast yourself and catch it. Unfortunate that both C# and VB chose to implement implicit casts in foreach.... --MB > -----Original Message----- > From: Discussion of advanced .NET topics. [mailto:ADVANCED- > [EMAIL PROTECTED] On Behalf Of Bob Provencher > Sent: Friday, December 14, 2007 1:58 PM > To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM > Subject: Re: [ADVANCED-DOTNET] Method that returns List<BaseClass> > > I think if someone puts a Report in your list, which it's type implies > is > allowed, your foreach will throw an invalid cast exception. > > -----Original Message----- > From: Discussion of advanced .NET topics. > [mailto:[EMAIL PROTECTED] On Behalf Of Ron Young > Sent: Friday, December 14, 2007 1:46 PM > To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM > Subject: Re: [ADVANCED-DOTNET] Method that returns List<BaseClass> > > Indeed it does. Thank you. > > I was under the impression that if the method that returned derived > reports > ultimately returned a list of the base report, then the client would > get the > properties defined in the base report. > > But it's up to the client to determine what types of reports are in the > list, so this works: > > // client-side > List<Report> reports = provider.GetReports(); > foreach (ReportA item in reports) > WL(item.MyName); > > =================================== > This list is hosted by DevelopMentor(r) http://www.develop.com > > View archives and manage your subscription(s) at > http://discuss.develop.com =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
