The DataGrid supports group expand and collapse operations either through the UI by tapping on the group headers, or programmatically. By default, all the groups are expanded.
This section provides an overview of the methods and commands used to control the expand/collapse state of the DataGrid groups.
To manipulate the collapsible DataGrid groups, first you will need to call its
GetDataView method. In short, the
GetDataView method provides a view of the
ItemsSource after all the sorting, grouping, and filtering operations are applied. The return type is
IDataViewCollection which exposes the
collapse methods described in the following sections.
var dataView = this.dataGrid.GetDataView();
To expand all groups, use the
ExpandAll method and, respectively, the
CollapseAll method to collapse all groups.
//expand all var dataView = this.dataGrid.GetDataView(); dataView.ExpandAll(); //collapse all var dataView = this.dataGrid.GetDataView(); dataView.CollapseAll();
You can retrieve the first-level groups through the
GetGroups method of the
IDataViewCollection object and use
CollapseGroup to make a certain group to expand or collapse respectively. You can check whether a group is expanded trough the
The following example demonstrates how these methods are used:
var dataView = this.dataGrid.GetDataView(); var rootGroups = dataView.GetGroups(); var isFirstExpanded = dataView.GetIsExpanded(rootGroups.First()); //expand a certain group dataView.ExpandGroup(rootGroups.First()); //collapse a certain group dataView.CollapseGroup(rootGroups.First());
IDataViewCollection provides the
CollapseItem methods that take a data item as a parameter and expand/collapse the immediate group containing this item.
var lastItem = (dataGrid.ItemsSource as IEnumerable<City>).Last(); var dataView = this.dataGrid.GetDataView(); dataView.CollapseItem(lastItem);