TreeDataGridSelectionModel Class
Definition
Base class for selection models in TreeDataGrid.
public class TreeDataGridSelectionModel
Remarks
This class may be derived from in order to implement a custom selection model. Custom
selection models are an experimental feature: the members required to implement one are
marked with [Experimental] and may be changed or removed in a future release.
Properties
| Name | Description |
|---|---|
| IsCellSelectionModel | Gets a value indicating whether this is a cell selection model. |
| SingleSelect | Gets or sets a value indicating whether only a single item can be selected at a time. |
| Source | Gets the data source for the selection model. |
IsCellSelectionModel Property
Gets a value indicating whether this is a cell selection model.
public bool IsCellSelectionModel { get; set; }
SingleSelect Property
Gets or sets a value indicating whether only a single item can be selected at a time.
public bool SingleSelect { get; set; }
Source Property
Gets the data source for the selection model.
public System.Collections.IEnumerable Source { get; set; }
Events
| Name | Description |
|---|---|
| IndexesChanged | Occurs when item indexes change due to insertions or removals in the data source. |
| PropertyChanged | No summary available. |
| SelectionChanged | Occurs when the selection changes, providing unified event args with row and cell index information. |
| SourceReset | Occurs when the data source is reset. |
IndexesChanged Event
Occurs when item indexes change due to insertions or removals in the data source.
public event EventHandler<Avalonia.Controls.Selection.TreeDataGridIndexesChangedEventArgs> IndexesChanged
PropertyChanged Event
public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged
SelectionChanged Event
Occurs when the selection changes, providing unified event args with row and cell index information.
public event EventHandler<Avalonia.Controls.Selection.TreeDataGridSelectionChangedEventArgs> SelectionChanged
SourceReset Event
Occurs when the data source is reset.
public event EventHandler<Avalonia.Controls.Selection.TreeDataGridItemsResetEventArgs> SourceReset
Remarks
This event is raised when a collection in the hierarchical data structure is reset, such as when a collection is cleared or replaced with a new collection.
Due to design limitations of collection reset events, the selection model cannot automatically preserve selection state when a collection is reset. The reset event doesn't provide information about which items were removed or how they map to new items.
Applications that need to maintain selection across collection resets must handle this event and manually restore the selection based on their knowledge of the data model. For example, you might store the IDs or unique identifiers of selected items before the reset, and then re-select them after the reset by finding the new indices of those items.
The Avalonia.Controls.Selection.TreeDataGridItemsResetEventArgs.ParentIndex property indicates which part of the hierarchical structure was reset, allowing you to determine whether to restore selection for the entire collection or just a subtree.