Project Description Fast WPF datagrid control designed to work with large datasets, with mandatory data virtualization.

Update 2026-11-05 - the project now targets .NET 10, namespaces/assemblies are CodingConnected.FastWpfGrid and CodingConnected.WriteableBitmapEx.Wpf, version 1.1.0

This repository is a fork of https://fastwpfgrid.codeplex.com/

• fast DataGrid control for .NET - WPF
• designed for large data sets
• both columns and rows are defined in model
• uses MVVM design pattern, but (for performance reasons) does not use classic WPF binding
• works only with data virtualization (UI virtualization is not needed as in other WPF datagrid controls)
• for rendering WriteableBitmapEx library is used

Features

• Fast scrolling and rendering
• Excel-like mouse-drag selecting
• Hide columns/rows
• Frozen columns/rows
• Own rendering, WPF templates are not used. Supported objects - text (with italic, bold attributes), images, image buttons

Changes in 1.1.0

• Target framework: .NET 10 (net10.0-windows).
• Assemblies/namespaces renamed to CodingConnected.FastWpfGrid / CodingConnected.WriteableBitmapEx.Wpf.
• Removed WriteableBitmap.Freeze() of the previous draw buffer. It was a .NET Framework-era GC workaround; on .NET 8/10 buffers are collected normally, and Freeze() destroys the bitmap's native surface permanently, which made RenderGrid throw ArgumentNullException: SafeHandle cannot be null.
• RenderGrid now catches rendering failures, raises FastGridControl.RenderFailed, recreates the draw buffer and re-renders instead of surfacing a DispatcherUnhandledException. After 3 consecutive failures it stops retrying until the next invalidation.
• BitmapContext is now a sealed class instead of a struct, so copying a context can no longer unlock a bitmap that another live context still uses. It registers in the static ref-count map only after Lock() succeeds, Dispose() is double-dispose-safe and always unlocks (even if AddDirtyRect throws), and non-32bpp bitmaps are rejected instead of being indexed with a wrong stride.
• ToByteArray(offset, count) now treats offset as a Pixels index as documented (it used to pass bytes), and all byte-array copies are bounds-checked. Crop clamps non-positive sizes and the Blit fast path checks source bounds before its memcpy.
• DPI changes are detected from the visual (DpiDetector.SetKoefs), so moving to another monitor or an RDP scaling change rebuilds the buffer and glyph cache instead of using stale scale factors. FastGridControl.ClearCaches() also clears the shared LetterGlyphTool font cache, which is not DPI-keyed.
• ClearType glyph brushes are disposed (GDI handle churn), and build settings (unsafe, WPF define) no longer depend on the Platform name.
• Fixed the copy shortcut: it no longer runs for every key press while Ctrl is held (operator precedence bug), guarded scrolling when there is no draw buffer yet, and made empty text/image blocks null-safe.

Model implementation

Grid control is bind to model, which controls displayed data. Below is example of model implementation. Refer to the test WPF app for further details.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CodingConnected.FastWpfGrid;

namespace FastWpfGridTest
{
    public class GridModel1 : FastGridModelBase
    {
        private Dictionary<Tuple<int, int>, string> _editedCells = new Dictionary<Tuple<int, int>, string>();
        private static string[]()() _columnBasicNames = new[]()() { "", "Value:", "Long column value:" };

        public override int ColumnCount
        {
            get { return 100; }
        }

        public override int RowCount
        {
            get { return 1000; }
        }

        public override string GetCellText(int row, int column)
        {
            var key = Tuple.Create(row, column);
            if (_editedCells.ContainsKey(key)) return _editedCells[key](key);


            return String.Format("{0}{1},{2}", _columnBasicNames[column % _columnBasicNames.Length](column-%-_columnBasicNames.Length), row + 1, column + 1);
        }

        public override void SetCellText(int row, int column, string value)
        {
            var key = Tuple.Create(row, column);
            _editedCells[key](key) = value;
        }

        public override IFastGridCell GetGridHeader(IFastGridView view)
        {
            var impl = new FastGridCellImpl();
            var btn = impl.AddImageBlock(view.IsTransposed ? "/Images/flip_horizontal_small.png" : "/Images/flip_vertical_small.png");
            btn.CommandParameter = CodingConnected.FastWpfGrid.FastGridControl.ToggleTransposedCommand;
            btn.ToolTip = "Swap rows and columns";
            return impl;
        }
    }
}