Open.DataGrid 1.2.13

OpenDataGrid

A high-performance, fully custom WPF grid built from scratch — no DataGrid, ListView, VirtualizingStackPanel, or any built-in WPF virtualization mechanism. Handles 1,000,000 rows at 60 fps using a row ring-buffer and direct property access through compiled IL delegates.

Features

• True virtualization — only visibleRows + 8 row objects exist in memory, regardless of data size
• O(1) scroll — ring-buffer rotation, zero allocations during scrolling
• Async sorting and filtering — background Task.Run with cancellation tokens and epoch-based staleness detection
• Loading overlay — semi-transparent overlay and/or progress bar during sorting, filtering, and collection rebuilds
• Per-row and per-cell coloring — binding path, selector function, or static brush with a priority hierarchy
• Full keyboard navigation — row and cell modes, F2 to edit, Tab to commit, Escape to cancel
• In-place editing — typed columns with validation, live-edit mode (saves on every keystroke)
• Column resizing — drag the resize thumb in the header
• Column reordering — header drag & drop (AllowColumnReorder), with public ReorderColumn API
• Text and combo filters — debounced multi-field filter, distinct-value filter; multiple filters combine as AND
• Column hiding — via HiddenColumns DP, matched by header or binding path
• Row checking (CheckedItems) — toggle by click or key (ToggleCheckedKey), checked-row styling, MarkedItems as union of checked and selected
• 436 unit tests (+ 75 integration) across 41 files

Requirements

• .NET Framework 4.6.2+
• WPF (Windows only)

Quick Start

1. Add a reference

Add a project reference to Open.DataGrid or install the NuGet package into your WPF project.

2. Basic grid in XAML

<Window xmlns:edg="clr-namespace:Open.DataGrid;assembly=Open.DataGrid">

    <edg:OpenDataGrid x:Name="TheGrid"
                      DataSource="{Binding Items}"
                      SelectedItem="{Binding SelectedItem}"
                      NavigationMode="Cell"
                      RowHeight="24"
                      AlternateRowBackground="#F5F5F5">
        <edg:OpenDataGrid.Columns>
            <edg:OpenDataGridLabelColumn    Header="ID"       BindingPath="Id"       Width="60"/>
            <edg:OpenDataGridLabelColumn    Header="Name"     BindingPath="Name"     Width="180"/>
            <edg:OpenDataGridDecimalColumn  Header="Price"    BindingPath="Price"    Width="100"/>
            <edg:OpenDataGridIntegerColumn  Header="Quantity" BindingPath="Quantity" Width="80"/>
            <edg:OpenDataGridBooleanColumn  Header="Active"   BindingPath="IsActive" Width="70"/>
            <edg:OpenDataGridDateTimeColumn Header="Created"  BindingPath="CreatedAt" Format="yyyy-MM-dd" Width="120"/>
        </edg:OpenDataGrid.Columns>
    </edg:OpenDataGrid>

</Window>

3. Add filters

<StackPanel Orientation="Horizontal" Margin="0,0,0,4">
    
    <edg:OpenDataGridTextFilter Grid="{Binding ElementName=TheGrid}"
                                FilterFields="Name,Description"
                                Width="220"
                                DebounceDelay="300"/>

    
    <edg:OpenDataGridTextFilter Grid="{Binding ElementName=TheGrid}"
                                FilterFields="Name"
                                EnterCommand="{Binding OpenItemCommand}"
                                Width="220"/>

    
    <edg:OpenDataGridComboFilter Grid="{Binding ElementName=TheGrid}"
                                 FilterField="Category"
                                 Width="160"
                                 Margin="8,0,0,0"/>
</StackPanel>

Multiple filters on the same grid work together as AND.

OpenDataGridTextFilter.EnterCommand — when bound, Enter executes the command with Grid.SelectedItem as the parameter and does not move focus to the grid (regardless of FocusGridOnConfirm).

Column Types

All columns share common DPs: Header, BindingPath, Width, MinWidth, MaxWidth, IsReadOnly, IsSortable, IsVisible, Background, Foreground, BackgroundOverridesData, CellBackgroundBindingPath, SortDirection.

Key Dependency Properties

*CellBackgroundBindingPath is a column-level DP, not a grid-level one.

Public Methods

// Scroll to a specific data item and column (works with active sorting/filtering)
grid.ScrollToItem(dataIndex, columnIndex: 0);

// Move cell focus to a column by Header or BindingPath (Cell mode only)
grid.SelectColumn("Name");

// Reorder columns from code (requires AllowColumnReorder = true)
// fromVisibleIndex — current position; toVisibleIndex — insertion point (0..N)
grid.ReorderColumn(fromVisibleIndex: 1, toVisibleIndex: 0);

// Commit the active cell edit from code
grid.CommitEdit();

Coloring Priority

Cell background is resolved in the following order (highest wins):

1. Focused cell highlight (auto-contrast from SelectionBrush)
2. SelectionBrush of the selected row
3. Column.Background when BackgroundOverridesData = true
4. Data property via CellBackgroundBindingPath
5. Column.Background when BackgroundOverridesData = false
6. Row background (AlternateRowBackground / RowBackgroundSelector / RowBackgroundBindingPath / RowBackground)

Architecture

OpenDataGrid (Controls/)
├── GridLifecycleController    — lifecycle state machine (NoTemplate→Ready⇄WaitingForViewport, Unloaded)
├── RowVirtualizationEngine    — row ring-buffer, O(1) math
├── ColumnVirtualizationEngine — prefix-sum, binary-search of the visible range
├── SortEngine                 — sort on index array (data never moved), background Task.Run
├── FilterEngine               — predicate registry, AND logic, thread-safe
├── NavigationEngine           — keyboard FSM, Row/Cell modes
├── SelectionFocusSynchronizer — selection and focus state hub
├── GridWorkCoordinator        — async work tracking, WorkToken RAII, overlay visibility
├── HeaderPresenter            — header cells, resize thumbs, DPD subscriptions
└── HiddenColumnsTracker       — HiddenColumns DP logic, incremental visibility updates

Property access via Fasterflect — compiled IL delegates (~10× faster than PropertyInfo.GetValue), global cache in PropertyAccessorCache.

Demo Application

Open.DataGrid.Demo generates 1,000,000 rows of SampleRow (40 typed properties) on a background thread. Every 10th row is read-only; every 100th has a yellow background. Demonstrates all column types, filters, sorting, and the loading overlay.

Building

Requires Visual Studio 2022 or MSBuild from a VS Developer Command Prompt:

msbuild OpenDataGrid.slnx -restore

Run the demo:

src\Open.DataGrid.Demo\bin\Debug\net462\Open.DataGrid.Demo.exe

Run tests:

vstest.console.exe src\Open.DataGrid.Tests\bin\Debug\net462\Open.DataGrid.Tests.dll

Skip integration tests (headless CI):

vstest.console.exe src\Open.DataGrid.Tests\bin\Debug\net462\Open.DataGrid.Tests.dll /TestCaseFilter:"TestCategory!=Integration"

License

MIT