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This option forces the content in the RowDetailsTemplate to be shown for every row. The content will be shown regardless of user interaction.

give you the ability to customize the experience with item-level details. The DataGrid extends the same type of power to the column headers.

The DataGrid gives you the ability to customize every part of it, including the headers. The headers of a DataGrid are split across two separate categories: row and column. By default, your DataGrid will show both, but you can control this by changing the HeadersVisibility property. This property uses one of the options available in the DataGridHeadersVisibility enumeration, which are shown in table 12.3.

Table 12.3 Option The options available through the DataGridHeadersVisibility enumeration Example Description This option displays both row and column headers. This is the default value.

The DataGridHeadersVisibility enumeration is used to set whether a header type is visible. You can also customize what the header looks like and how it behaves through the DataGridColumn class s Header property. This property simply repre-

sents the column header content, so it uses the same content-related information you ve already learned about. As you ve seen, the DataGrid empowers you to fully customize how your data is presented. These customizations can be applied at the header, row, and column levels. Note that you don t have to make any of these adjustments. If you re looking for a quick way to show your data in a tabular format, you can rely on the fact that the AutoGenerateColumns property defaults to true. Either way, once your data is loaded, you can enable your users to edit the data directly within the grid.

In addition to presenting data, the DataGrid has the ability to edit data. Users will be able to edit the contents of a DataGrid as long as the IsReadOnly property is set to false. By default it is, so your users have the flexibility to interact with their data in a familiar interface. As they do so, you can watch for the beginning of the editing process through two events. These events are triggered by the DataGrid and are called BeginningEdit and PreparingCellForEdit. The BeginningEdit event gives you the opportunity to make last-minute adjustments just before users do their thing. In some situations, you may want to prevent a user from editing a cell due to previous inputs. For these occasions, the BeginningCellEdit event exposes a bool Cancel property within its DataGridBeginningEditEventArgs parameter. By setting this property to true, the event will stop running. If the event does complete in its entirety, the PreparingCellForEdit event will also be fired. The PreparingCellForEdit is fired when the content of a DataGridTemplateColumn enters the editing mode. This event exists to give you the opportunity to override any changes that may have been made in the BeginningEdit event. Once this event and/or the BeginningEdit event have completed without cancellation, users will be given the reins. After they re done editing the data in the DataGrid, they may decide they want to re-sort the data.

The DataGrid has built-in support for sorting collections that implement the IList interface. This interface is a part of the System.Collections namespace and is heavily used throughout the Silverlight .NET framework so you can readily sort almost any collection of objects. If you don t like the way that the DataGrid sorts your collection, you re free to customize the sorting by binding to a collection that implements the ICollectionView interface. Either way, the DataGrid can be used to sort these collections via the SortMemberPath property. The SortMemberPath property is a string available on the DataGridColumn class, so this property can be used by any of the options shown in table 12.3. Regardless of which option you use, the user will be empowered to sort the column in either ascending or descending order, as demonstrated in listing 12.4.