Summary and detail in listbox

Your sample doesn’t work with non-english system locale settings. Just try to change Decimal symbol to comma for example (russian format: decimal symbol is comma, digit grouping symbol is space).

—————————
Windows Internet Explorer
—————————

Silverlight error message
ErrorCode: 4002
ErrorType: ManagedRuntimeError
Message: System.FormatException: Input string was not in a correct format.

at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)

at System.Number.ParseDecimal(String value, NumberStyles options, NumberFormatInfo numfmt)

at System.Decimal.Parse(String s)

at slapp1.Page.b__4(Customer l)

at System.Linq.Enumerable.WhereSelectListIterator`2.MoveNext()

at System.Linq.Enumerable.Sum(IEnumerable`1 source)

at slapp1.Page.Page_Loaded(Object sender, RoutedEventArgs e)

at System.Windows.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args)

at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, String eventName)

—————————
OK
—————————

Just change
decimal total = (from l in li select Decimal.Parse(l.Total)).Sum();

to
decimal total = (from l in li select Decimal.Parse(l.Total, System.Globalization.CultureInfo.InvariantCulture)).Sum();

in Page.xaml.cs

very nice.
any chance of doing it in VB