10.6 Summary

Windows Forms provides a very flexible architecture for binding data sources to control properties. Any property of any object can act as a data source, and any control can participate. Lists of objects can also act as data sources, and for these the system will provide a CurrencyManager object to track the current position in the list. Certain controls support complex binding, which means that they are able to display entire lists at a time. There are also specialized data sources—the DataTable and DataSet classes allow multiple tables of data to be held in memory along with information about relations between those tables. Using these, programs can let the user browse through substantial sets of data, and selectively display related details with a minimal number of round trips to the database. Controls bound to a DataSet or DataTable always present data as filtered by a DataView. By default, this will either show the whole table or will just display rows related to a selected item in a parent table, but it is possible to build custom views with arbitrary filtering criteria. The DataGrid control provides highly specialized support for data binding, allowing all properties of all items in a table to be displayed, and it can even traverse relations between multiple tables.