Column types

info

This control is available as part of Avalonia Accelerate Business or higher.

TreeDataGridTextColumn

TreeDataGridTextColumn displays property values as text. Values are converted to strings using ToString() for display. For editable columns, text input is converted back to the property type using Convert.ChangeType().

XAML usage

<!-- Read-only column -->
<TreeDataGridTextColumn Header="First Name" Binding="{Binding FirstName}" />

<!-- Column width -->
<TreeDataGridTextColumn Header="First Name" Binding="{Binding FirstName}" Width="200" />

<!-- Formatting -->
<TreeDataGridTextColumn Header="Birth Date" Binding="{Binding BirthDate, StringFormat='{}{0:yyyy-MM-dd}'}" />

<!-- Alignment and trimming -->
<TreeDataGridTextColumn Header="GDP" Binding="{Binding GDP}"
                        TextAlignment="Right"
                        MaxWidth="150" />

Columns bound to a writable property are editable by default. To make a column read-only, set IsReadOnly="True".

Code-behind usage

Use the WithTextColumn fluent method. The getter expression is used for two-way binding automatically when the expression is writable. When the header matches the property name, you can omit it:

// Header inferred from property name
source.WithTextColumn(x => x.FirstName)

// Explicit header
source.WithTextColumn("First Name", x => x.FirstName)

// With options
source.WithTextColumn("First Name", x => x.FirstName, o =>
{
    o.Width = new GridLength(200);
    o.IsReadOnly = true;
})

Options

Options can be set as attributes in XAML or configured via the TextColumnCreateOptions lambda in code-behind:

Option	XAML attribute	Default	Description
Width	Width	Auto	Column width
IsReadOnly	IsReadOnly	false	Whether the column is read-only
StringFormat	Use binding StringFormat	N/A	Format string for display (e.g. "{0:C}" for currency)
Culture	N/A	CurrentCulture	Culture for formatting
TextAlignment	TextAlignment	Left	Horizontal text alignment
TextTrimming	TextTrimming	N/A	How text is trimmed when too long
TextWrapping	TextWrapping	NoWrap	How text wraps within the cell
IsTextSearchEnabled	IsTextSearchEnabled	true	Whether the column participates in text search
CanUserResize	CanUserResize	true	Whether the user can resize the column
CanUserSortColumn	CanUserSortColumn	true	Whether the user can sort by clicking the header
AllowTriStateSorting	AllowTriStateSorting	false	Allow ascending/descending/unsorted states
MinWidth / MaxWidth	MinWidth / MaxWidth	N/A	Minimum and maximum column widths
CompareAscending / CompareDescending	N/A	N/A	Custom comparison functions for sorting
BeginEditGestures	BeginEditGestures	N/A	Gestures that trigger edit mode (None, F2, Tap, DoubleTap, WhenSelected)

note

IsTextSearchEnabled defaults to true for text columns. Set it to false explicitly if you don't want a column to participate in text search.

TreeDataGridCheckBoxColumn

TreeDataGridCheckBoxColumn displays Boolean values as checkboxes.

XAML usage

<!-- Basic checkbox -->
<TreeDataGridCheckBoxColumn Header="Active" Binding="{Binding IsActive}" />

<!-- Read-only, non-resizable -->
<TreeDataGridCheckBoxColumn Binding="{Binding IsChecked}"
                            CanUserResize="False"
                            IsReadOnly="True" />

Code-behind usage

Use WithCheckBoxColumn for bool properties, or WithThreeStateCheckBoxColumn for bool? (nullable) properties:

// Basic checkbox
source.WithCheckBoxColumn(x => x.IsActive)

// With explicit header
source.WithCheckBoxColumn("Active", x => x.IsActive)

// Three-state checkbox for nullable bool
source.WithThreeStateCheckBoxColumn(x => x.IsChecked)

// With options
source.WithCheckBoxColumn(x => x.IsActive, o =>
{
    o.CanUserResize = false;
    o.Width = new GridLength(80);
})

Options

Option	XAML attribute	Default	Description
Width	Width	Auto	Column width
IsReadOnly	IsReadOnly	false	Whether the column is read-only
CanUserResize	CanUserResize	true	Whether the user can resize the column
CanUserSortColumn	CanUserSortColumn	true	Whether the user can sort by clicking the header
AllowTriStateSorting	AllowTriStateSorting	false	Allow ascending/descending/unsorted states
MinWidth / MaxWidth	MinWidth / MaxWidth	N/A	Minimum and maximum column widths
CompareAscending / CompareDescending	N/A	N/A	Custom comparison functions for sorting
BeginEditGestures	BeginEditGestures	N/A	Gestures that trigger edit mode

TreeDataGridHierarchicalExpanderColumn

TreeDataGridHierarchicalExpanderColumn displays hierarchical tree data with an expander control to show/hide child items. This column type can only be used with hierarchical data.

The expander column wraps an inner column (typically a TreeDataGridTextColumn or TreeDataGridTemplateColumn) which defines what content appears next to the expander icon.

XAML usage

Define the expander column in XAML with bindings for children, and nest the inner column as content:

<TreeDataGridHierarchicalExpanderColumn Header="Name" Width="*"
                                        ChildrenBinding="{Binding Children}"
                                        HasChildrenBinding="{Binding HasChildren}"
                                        IsExpandedBinding="{Binding IsExpanded}">
  <TreeDataGridTextColumn Binding="{Binding Name}" />
</TreeDataGridHierarchicalExpanderColumn>

Attribute	Description
ChildrenBinding	Binding to the children collection for each row (required)
HasChildrenBinding	Binding to check if a row has children without loading them (useful for lazy loading)
IsExpandedBinding	Binding to persist the expanded state to a property in the model

Code-behind usage

For a text column inside the expander, use WithHierarchicalExpanderTextColumn:

source.WithHierarchicalExpanderTextColumn(x => x.Name, x => x.Children)

// With options
source.WithHierarchicalExpanderTextColumn(x => x.Name, x => x.Children, o =>
{
    o.Width = GridLength.Star;
    o.HasChildren = x => x.HasChildren;
    o.IsExpanded = x => x.IsExpanded;
})

For a custom inner column (e.g. a template column), use WithHierarchicalExpanderColumn:

source.WithHierarchicalExpanderColumn(
    "Name",
    new TreeDataGridTemplateColumn(null, "FileNameCell", "FileNameEditCell"),
    x => x.Children,
    o =>
    {
        o.Width = GridLength.Star;
        o.HasChildren = x => x.HasChildren;
        o.IsExpanded = x => x.IsExpanded;
    })

TreeDataGridTemplateColumn

TreeDataGridTemplateColumn uses data templates to render cell content, allowing complete control over appearance and behavior.

XAML usage

Define the cell template (and optional editing template) inline:

<TreeDataGridTemplateColumn Header="Region">
  <TreeDataGridTemplateColumn.CellTemplate>
    <DataTemplate DataType="m:Country">
      <TextBlock Text="{Binding Region}" />
    </DataTemplate>
  </TreeDataGridTemplateColumn.CellTemplate>
  <TreeDataGridTemplateColumn.CellEditingTemplate>
    <DataTemplate DataType="m:Country">
      <ComboBox ItemsSource="{x:Static m:Countries.Regions}"
                SelectedItem="{Binding Region}" />
    </DataTemplate>
  </TreeDataGridTemplateColumn.CellEditingTemplate>
</TreeDataGridTemplateColumn>

Code-behind usage

Using IDataTemplate instances:

source.WithTemplateColumn(
    "Selected",
    new FuncDataTemplate<Person>((_, _) => new CheckBox
    {
        [!CheckBox.IsCheckedProperty] = new Binding("IsSelected"),
    }))

Using XAML resource keys:

Define a template in your TreeDataGrid.Resources:

<TreeDataGrid Source="{Binding Source}">
  <TreeDataGrid.Resources>
    <DataTemplate x:Key="CheckBoxCell">
      <CheckBox IsChecked="{Binding IsSelected}" />
    </DataTemplate>
  </TreeDataGrid.Resources>
</TreeDataGrid>

Then reference it by key:

source.WithTemplateColumnFromResourceKeys("Selected", "CheckBoxCell")

// With separate edit template
source.WithTemplateColumnFromResourceKeys("Selected", "CheckBoxCell", "CheckBoxCellEdit")

Options

Option	XAML attribute	Default	Description
Width	Width	Auto	Column width
TextSearchBinding	N/A	N/A	Binding to extract searchable text from the model
CanUserResize	CanUserResize	true	Whether the user can resize the column
CanUserSortColumn	CanUserSortColumn	true	Whether the user can sort by clicking the header
AllowTriStateSorting	AllowTriStateSorting	false	Allow ascending/descending/unsorted states
MinWidth / MaxWidth	MinWidth / MaxWidth	N/A	Minimum and maximum column widths
CompareAscending / CompareDescending	N/A	N/A	Custom comparison functions for sorting
BeginEditGestures	BeginEditGestures	N/A	Gestures that trigger edit mode

To enable text search on a template column, set TextSearchBinding using CompiledBinding.Create:

source.WithTemplateColumnFromResourceKeys("Name", "FileNameCell", "FileNameEditCell", o =>
{
    o.TextSearchBinding = CompiledBinding.Create<FileTreeNodeModel, string>(x => x.Name);
})

TreeDataGridRowHeaderColumn

TreeDataGridRowHeaderColumn displays row headers (typically row numbers) in the leftmost column.

XAML usage

<TreeDataGrid ItemsSource="{Binding Data}">
  <TreeDataGridRowHeaderColumn />
  <TreeDataGridTextColumn Header="Name" Binding="{Binding Name}" />
</TreeDataGrid>

Code-behind usage

source.WithRowHeaderColumn()

See also

• TreeDataGrid