Use the igrouping interface for Windows Phone longlistselector

Longlistselector is special. It requires that the data source at least implement the ienumerable <t> interface, and then each element in it must implement the ienumerable <t> interface.

Considering that you need to provide the group title, it would be better if you can use the LINQ statement to query, because the returned object implements the igrouping <tkey, telement> interface.

This interface inherits the ienumerable <t> interface. however, you cannot directly query the returned group objects by using the LINQ group, because the data binding of Silverlight uses the type. getproperty () to get the specified property. This method cannot get the interface property of the display implementation. the tkey attribute of the group object is implemented by the igrouping <tkey, telement> interface through display. Therefore, it must be as follows:

Public class grouping <tkey, telement>: List <telement> {public grouping (igrouping <tkey, telement> G): Base (g) {key = G. key ;}public tkey {Get; Set ;}}

From B in Set

Select new grouping <key, element> (g );

In this way, you can use the LINQ statement.