TreeDataGridCellsPresenter Class

Definition

Namespace:Avalonia.Controls.Primitives

Assembly:Avalonia.Controls.TreeDataGrid

Package:Avalonia.Controls.TreeDataGrid

Presents and manages cells within a row of a Avalonia.Controls.TreeDataGrid control.

public class TreeDataGridCellsPresenter

Inheritance: TreeDataGridColumnarPresenterBase<IColumn> -> TreeDataGridCellsPresenter

Implements:IChildIndexProvider

Remarks

TreeDataGridCellsPresenter is responsible for creating, recycling, and arranging cells horizontally within a row of a TreeDataGrid. It handles the virtualization of cells, ensuring that only visible cells are realized in the visual tree to improve performance.

This presenter is typically used within a Avalonia.Controls.Primitives.TreeDataGridRow control template to display the cells for that row. It coordinates with its parent row and the TreeDataGrid to manage cell lifecycle, selection state, and layout.

Constructors

Name	Description
TreeDataGridCellsPresenter	No summary available.

TreeDataGridCellsPresenter Constructor

public TreeDataGridCellsPresenter()

Methods

Name	Description
GetChildIndex	Gets child's actual index in order of the original source.
Realize	Prepares the presenter to display cells for the specified row index.
TryGetTotalCount	No summary available.
Unrealize	Releases resources used by the presenter and prepares it for reuse.
UpdateRowIndex	Updates the row index of this presenter and all its cells.

GetChildIndex Method

Gets child's actual index in order of the original source.

public int GetChildIndex(Avalonia.LogicalTree.ILogical child)

Parameters

child Avalonia.LogicalTree.ILogical

Logical child.

Returns

int

Index or -1 if child was not found.

Realize Method

Prepares the presenter to display cells for the specified row index.

public void Realize(int index)

Parameters

index int

The index of the row to realize.

Remarks

This method is called by the TreeDataGrid when a row needs to be prepared for display. It initializes the presenter with the specified row index and triggers a measure pass to create and arrange the cells.

Exceptions

• The presenter is already realized.

TryGetTotalCount Method

public bool TryGetTotalCount(int& count)

Parameters

count int&

Returns

bool

Unrealize Method

Releases resources used by the presenter and prepares it for reuse.

public void Unrealize()

Remarks

This method is called by the TreeDataGrid when a row is no longer needed for display. It clears the presenter's row index and recycles all cell elements.

Exceptions

• The presenter is not realized.

UpdateRowIndex Method

Updates the row index of this presenter and all its cells.

public void UpdateRowIndex(int index)

Parameters

index int

The new row index.

Remarks

This method is called when the index of the row changes, such as when rows are inserted or removed above it. It updates the presenter's row index and updates the row index of all realized cells.

Exceptions

• The index is out of range.
• The presenter is not realized.

Properties

Name	Description
FrozenColumnCount	Gets or sets the number of frozen columns.
RowIndex	Gets the index of the row that this presenter is currently displaying.
Rows	Gets or sets the rows collection from which to obtain cell data.

FrozenColumnCount Property

Gets or sets the number of frozen columns.

public int FrozenColumnCount { get; set; }

Remarks

Frozen columns do not scroll horizontally and remain visible at all times.

RowIndex Property

Gets the index of the row that this presenter is currently displaying.

public int RowIndex { get; set; }

Value

The zero-based row index, or -1 if the presenter is not realized.

Rows Property

Gets or sets the rows collection from which to obtain cell data.

public Avalonia.Controls.Models.TreeDataGrid.IRows Rows { get; set; }

Value

The collection of rows used to populate cells in this presenter.

Fields

Name	Description
FrozenColumnCountProperty	Defines the Avalonia.Controls.Primitives.TreeDataGridCellsPresenter.FrozenColumnCount property.
RowsProperty	Defines the Avalonia.Controls.Primitives.TreeDataGridCellsPresenter.Rows property.

FrozenColumnCountProperty Field

Defines the Avalonia.Controls.Primitives.TreeDataGridCellsPresenter.FrozenColumnCount property.

public Avalonia.StyledProperty<int> FrozenColumnCountProperty

RowsProperty Field

Defines the Avalonia.Controls.Primitives.TreeDataGridCellsPresenter.Rows property.

public Avalonia.DirectProperty<Avalonia.Controls.Primitives.TreeDataGridCellsPresenter, Avalonia.Controls.Models.TreeDataGrid.IRows> RowsProperty

Events

Name	Description
ChildIndexChanged	Occurs when the index of a child element in the presenter changes.

ChildIndexChanged Event

Occurs when the index of a child element in the presenter changes.

public event EventHandler<Avalonia.LogicalTree.ChildIndexChangedEventArgs> ChildIndexChanged