Optimized retained and drawn cell paths

ProDataGrid keeps the normal generic themes and retained Avalonia cell templates as the compatibility default. Performance-sensitive grids can opt into smaller partial themes, direct typed value access, or drawn display cells independently. Editing always returns to the normal retained editor path.

Choose the smallest change that fits

Path	Cell representation	Best fit	Main trade-off
Standard retained	DataGridCell plus normal Avalonia content/template	Existing applications, arbitrary templates, converters, validation, and dynamic resources	Highest visual-tree and binding cost
Optimized retained theme	DataGridCell plus normal retained content	Applications that require Avalonia controls and layout but want fewer chrome and presenter controls	Explicit theme opt-in; choose lean or feature-preserving row/header variants
Retained direct text	A retained cell and TextBlock, with a compatible typed accessor	Large read-mostly text grids that still require retained controls	Incompatible binding features automatically fall back to the normal binding path
Direct retained text cell	DataGridDirectTextCell with a compatible typed accessor	Dense read-mostly flat grids that require retained input, automation, and editing	Uses the optimized direct-cell theme; incompatible accessors fall back to a value binding
Direct hierarchy presenter	One retained hierarchy cell containing the expander and optional TextBlock	Large tree grids that need normal controls, input, automation, and editing	Custom cell templates continue to use the standard hierarchy presenter
Drawn display	A DataGridCustomDrawingCell or a supported built-in column in Drawn mode	Very dense read-mostly grids where the smallest display tree matters most	Display is drawn; editing still uses retained controls

Start with the optimized retained theme. It improves proper Avalonia-layout cells and does not require custom drawing.

Load the partial optimized resources

Load a normal ProDataGrid theme first, then the optimized resource dictionary:

<Application.Styles>
  <FluentTheme />
  <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Fluent.v2.xaml" />
  <StyleInclude Source="avares://Avalonia.Controls.DataGrid/Themes/Optimized.xaml" />
</Application.Styles>

Themes/Optimized.xaml is additive. It does not replace or modify Themes/Generic.xaml, so existing applications remain on their current templates until they assign an optimized theme or enable an optimized column property.

Optimize ordinary retained Avalonia cells

For a feature-complete grid with no frozen columns, use the feature-preserving row and header variants:

<DataGrid RowTheme="{StaticResource DataGridOptimizedFeatureUnfrozenRowTheme}"
          CellTheme="{StaticResource DataGridOptimizedCellTheme}"
          ColumnHeaderTheme="{StaticResource DataGridOptimizedFeatureColumnHeaderTheme}"
          UseLightweightFiller="True" />

Use DataGridOptimizedFeatureRowTheme when left or right frozen columns are enabled. These variants retain row headers, row details, grid lines, current/focus/selection chrome, sort and filter indicators, resize handles, and column dragging.

For fixed-height, read-mostly surfaces that do not need those row/header features, use DataGridOptimizedUnfrozenRowTheme (or DataGridOptimizedRowTheme with frozen columns) and DataGridOptimizedColumnHeaderTheme. The lean variants intentionally omit row-header/details presenters and the generic header's feature controls.

Arbitrary DataGridTemplateColumn content remains an ordinary retained Avalonia control tree. The optimized cell theme only removes redundant cell chrome and hosts the content directly.

Avoid a display binding without giving up retained controls

DataGridTextColumn.UseDirectTextContent="True" keeps the ordinary retained DataGridCell and text element. When the column has compatible typed accessor metadata, the text element reads that accessor without creating a binding expression per realized cell:

<DataGridTextColumn Header="Name"
                    Binding="{Binding Name}"
                    UseDirectTextContent="True"
                    TrackDirectTextValueChanges="True" />

The equivalent column-definition properties are DataGridTextColumnDefinition.UseDirectTextContent and TrackDirectTextValueChanges. Set change tracking to False only when the displayed value is immutable; recycled cells still refresh for a new row item.

Direct access is decided for each realized item. A converter, explicit binding source, fallback/target-null behavior, incompatible runtime item type, or missing typed accessor uses the normal Avalonia binding path. This fallback preserves binding semantics for heterogeneous and templated grids.

Set UseDirectTextCell="True" when the retained display can use DataGridDirectTextCell instead of a DataGridCell containing a text element. The column still creates the normal retained editor when editing begins. Column definitions use DataGridTextColumnDefinition.UseDirectTextCell.

Optimize retained hierarchy cells

DataGridHierarchicalColumn offers two retained-control optimizations:

<DataGridHierarchicalColumn Header="Name"
                            Binding="{Binding Item.Name}"
                            UseOptimizedPresenter="True"
                            UseDirectTextContent="True"
                            TrackDirectTextValueChanges="True" />

UseOptimizedPresenter combines the cell and expander-presenter roles while retaining a normal Avalonia text control, hierarchy input, UI Automation, focus, and editing behavior. UseDirectTextContent additionally uses a compatible typed accessor. Set UseDirectCell="True" for the leanest retained hierarchy container. Custom hierarchy cell templates automatically stay on the standard presenter path.

Opt into drawn display cells

Supported built-in columns accept DisplayMode="Drawn":

<DataGridTextColumn Header="Name"
                    Binding="{Binding Name}"
                    DisplayMode="Drawn" />
<DataGridNumericColumn Header="Total"
                       Binding="{Binding Total}"
                       DisplayMode="Drawn" />

Unsupported configurations fall back to Retained. Use DataGridCustomDrawingColumn for a custom drawing operation or renderer. Drawn cells preserve selection/current/focus chrome and automation names, and switch to the normal retained editor when editing starts.

Sample gallery workloads

The sample gallery contains two dedicated workload pages:

• Optimized Cell Paths (Flat) switches one grid between standard retained, optimized retained theme, retained direct accessor, direct retained text cell, built-in drawn text, and custom Skia draw-operation paths. It starts with a 1,000-row preview and can generate up to 1,000,000 immutable rows; the default profiling target is 250,000 rows across seven columns.
• Optimized Cell Paths (Hierarchy) switches one tree grid between standard retained, optimized retained theme, optimized hierarchy presenter, direct retained hierarchy, built-in drawn companion cells, and custom Skia companion cells. Its default target is 149,792 nodes with separate load, expand-all, collapse-all, and equal-distance jump actions.

Each page displays the active container type and exact configuration, uses typed column definitions, and reports a whole-process managed-heap snapshot. Run one path per fresh process with the same window and dataset settings when comparing memory or frame behavior. The pages are exploratory profiling surfaces; use the benchmark harness for controlled elapsed-time and allocation results.

Validate the chosen path

Benchmark first layout, an equal-distance scroll/jump workload, and the application's actual templates separately. Record both elapsed time and allocated bytes. A drawn-cell win does not prove that a retained template improved, which is why ProDataGrid's benchmark matrix keeps standard retained, optimized retained, and drawn modes as separate lanes.

Keep the generic path when runtime resource replacement, an application-specific control template, or a binding feature is more important than the extra realized controls. The optimized paths are explicit options, not global behavior changes.

Related articles

• Column Definitions: Hot Path Integration
• Custom Drawing Columns and Skia
• Hierarchical Model: End-to-End
• Scrolling and Virtualization