Added stateful model.

SheetReader.AppTest/MainWindow.xaml.cs

@@ -18,7 +18,7 @@ public MainWindow()
             tc.ItemsSource = Sheets;
         }
 
-        public ObservableCollection<SheetData> Sheets { get; } = new();
+        public ObservableCollection<BookDocumentSheet> Sheets { get; } = [];
 
         protected override void OnKeyDown(KeyEventArgs e)
         {
@@ -28,7 +28,7 @@ protected override void OnKeyDown(KeyEventArgs e)
         }
 
         private void Exit_Click(object sender, RoutedEventArgs e) => Close();
-        private void About_Click(object sender, RoutedEventArgs e) => MessageBox.Show(Assembly.GetEntryAssembly()!.GetCustomAttribute<AssemblyTitleAttribute>()!.Title + " - " + (IntPtr.Size == 4 ? "32" : "64") + "-bit" + Environment.NewLine + "Copyright (C) 2021-" + DateTime.Now.Year + " Simon Mourier. All rights reserved.", Assembly.GetEntryAssembly().GetCustomAttribute<AssemblyTitleAttribute>()!.Title, MessageBoxButton.OK, MessageBoxImage.Information);
+        private void About_Click(object sender, RoutedEventArgs e) => MessageBox.Show(Assembly.GetEntryAssembly()!.GetCustomAttribute<AssemblyTitleAttribute>()!.Title + " - " + (IntPtr.Size == 4 ? "32" : "64") + "-bit" + Environment.NewLine + "Copyright (C) 2021-" + DateTime.Now.Year + " Simon Mourier. All rights reserved.", Assembly.GetEntryAssembly()!.GetCustomAttribute<AssemblyTitleAttribute>()!.Title, MessageBoxButton.OK, MessageBoxImage.Information);
         private void Open_Click(object sender, RoutedEventArgs e)
         {
             var ofd = new OpenFileDialog
@@ -49,30 +49,13 @@ private void Open_Click(object sender, RoutedEventArgs e)
         private void Load(string fileName)
         {
             Sheets.Clear();
-            var book = new Book();
             try
             {
-                foreach (var sheet in book.EnumerateSheets(fileName))
+                var book = new BookDocument();
+                book.Load(fileName);
+                foreach (var sheet in book.Sheets)
                 {
-                    // we need to load data for WPF data binding
-                    var sheetData = new SheetData { Name = sheet.Name, IsHidden = !sheet.IsVisible };
-                    foreach (var row in sheet.EnumerateRows())
-                    {
-                        var rowData = new RowData(row.Index, row.EnumerateCells().ToList());
-                        sheetData.Rows.Add(rowData);
-                    }
-
-                    sheetData.Columns = sheet.EnumerateColumns().ToList();
-                    if (sheetData.Columns.Count > 0)
-                    {
-                        sheetData.LastColumnIndex = sheetData.Columns.Max(x => x.Index);
-                    }
-
-                    if (sheetData.Rows.Count > 0)
-                    {
-                        sheetData.LastRowIndex = sheetData.Rows.Max(x => x.RowIndex);
-                    }
-                    Sheets.Add(sheetData);
+                    Sheets.Add(sheet);
                 }
             }
             catch (Exception ex)
@@ -84,10 +67,11 @@ private void Load(string fileName)
             // not sure why, but with only 1 tab, binding doesn't work...
             if (Sheets.Count == 1)
             {
-                var dummy = new SheetData();
-                Sheets.Add(dummy);
-                Sheets.Remove(dummy);
+                var first = Sheets[0];
+                Sheets.Add(first);
+                Sheets.RemoveAt(1);
             }
+
             Title = "Sheet Reader - " + Path.GetFileName(fileName);
         }
 

SheetReader.AppTest/SheetControl.cs

@@ -1,13 +1,14 @@
 using System;
 using System.Globalization;
+using System.Linq;
 using System.Windows;
 using System.Windows.Media;
 
 namespace SheetReader.AppTest
 {
     public class SheetControl : FrameworkElement
     {
-        public static readonly DependencyProperty SheetProperty = DependencyProperty.Register(nameof(Sheet), typeof(SheetData), typeof(SheetControl),
+        public static readonly DependencyProperty SheetProperty = DependencyProperty.Register(nameof(Sheet), typeof(BookDocumentSheet), typeof(SheetControl),
             new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender));
 
         public static readonly DependencyProperty ColumnSizeProperty = DependencyProperty.Register(nameof(ColumnSize), typeof(double), typeof(SheetControl),
@@ -16,7 +17,7 @@ public class SheetControl : FrameworkElement
         public static readonly DependencyProperty RowHeightProperty = DependencyProperty.Register(nameof(RowHeight), typeof(double), typeof(SheetControl),
             new FrameworkPropertyMetadata(20.0, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender));
 
-        public SheetData Sheet { get { return (SheetData)GetValue(SheetProperty); } set { SetValue(SheetProperty, value); } }
+        public BookDocumentSheet Sheet { get { return (BookDocumentSheet)GetValue(SheetProperty); } set { SetValue(SheetProperty, value); } }
         public double ColumnSize { get { return (double)GetValue(ColumnSizeProperty); } set { SetValue(ColumnSizeProperty, value); } }
         public double RowHeight { get { return (double)GetValue(RowHeightProperty); } set { SetValue(RowHeightProperty, value); } }
 
@@ -119,7 +120,7 @@ protected override void OnRender(DrawingContext drawingContext)
                 }
             }
 
-            foreach (var row in Sheet.Rows)
+            foreach (var row in Sheet.Rows.Values.OrderBy(r => r.RowIndex))
             {
                 foreach (var cell in row.Cells)
                 {

SheetReader.Wpf.Test/GlobalSuppressions.cs

@@ -0,0 +1,3 @@
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage("Interoperability", "SYSLIB1054:Use 'LibraryImportAttribute' instead of 'DllImportAttribute' to generate P/Invoke marshalling code at compile time", Justification = "Mostly useless")]

SheetReader.Wpf.Test/MainWindow.xaml

@@ -30,7 +30,10 @@
                     Header="Open _Recent"
                     IsEnabled="False">
                     <Separator />
-                    <MenuItem Name="ClearRecentFiles" Header="Clear Recent List" Click="ClearRecentFiles_Click" />
+                    <MenuItem
+                        Name="ClearRecentFiles"
+                        Click="ClearRecentFiles_Click"
+                        Header="Clear Recent List" />
                 </MenuItem>
                 <Separator />
                 <MenuItem

SheetReader.Wpf/SheetControl.cs

@@ -1,9 +1,10 @@
 using System;
-using System.Diagnostics;
 using System.Globalization;
+using System.Runtime.CompilerServices;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
+using SheetReader.Wpf.Utilities;
 
 namespace SheetReader.Wpf
 {
@@ -46,6 +47,8 @@ static SheetControl()
             DefaultStyleKeyProperty.OverrideMetadata(typeof(SheetControl), new FrameworkPropertyMetadata(typeof(SheetControl)));
         }
 
+        private static void Log(object? message = null, [CallerMemberName] string? methodName = null) => EventProvider.Default.WriteMessageEvent(methodName + ":" + message);
+
         private ScrollViewer? _scrollViewer;
         private SheetGrid? _grid;
 
@@ -68,7 +71,6 @@ public override void OnApplyTemplate()
 
         private void OnScrollChanged(object sender, ScrollChangedEventArgs e)
         {
-            Trace.WriteLine("OnScrollChanged");
             _grid?.InvalidateVisual();
         }
 
@@ -100,7 +102,6 @@ protected override Size MeasureCore(Size availableSize)
 
             protected override void OnRender(DrawingContext drawingContext)
             {
-                Trace.WriteLine("OnRender size:" + RenderSize);
                 if (control.Sheet == null || control.Sheet.Columns.Count == 0 || control.Sheet.Rows.Count == 0)
                     return;
 
@@ -109,20 +110,33 @@ protected override void OnRender(DrawingContext drawingContext)
 
                 var dpi = VisualTreeHelper.GetDpi(this);
                 var colWidth = control.GetColWidth();
+                var colFullWidth = colWidth + control.GridLineSize;
                 var rowHeight = control.GetRowHeight();
-                var fontSize = rowHeight * 0.6;
+                var rowFullHeight = rowHeight + control.GridLineSize;
 
-                var rowMargin = control.GetRowMargin();
-                var headerHeight = rowHeight;
+                var rowsHeaderWidth = control.GetRowMargin();
+                var rowsHeaderFullWidth = rowsHeaderWidth + control.GridLineSize;
+                var columnsHeaderHeight = rowHeight;
+                var columnsHeaderFullHeight = columnsHeaderHeight + control.GridLineSize;
+
+                var offsetX = control._scrollViewer?.HorizontalOffset ?? 0;
+                var offsetY = control._scrollViewer?.VerticalOffset ?? 0;
+                var viewWidth = control._scrollViewer?.ViewportWidth ?? RenderSize.Width;
+                var viewHeight = control._scrollViewer?.ViewportHeight ?? RenderSize.Height;
 
-                var firstColumnIndex = 0;
-                var offsetX = control._scrollViewer?.ContentHorizontalOffset ?? 0;
+                var firstDrawnColumnIndex = Math.Max((int)((offsetX - rowsHeaderFullWidth) / colFullWidth), 0);
+                var lastDrawnColumnIndex = Math.Max(Math.Min((int)((offsetX - rowsHeaderFullWidth + viewWidth) / colFullWidth), control.Sheet.LastColumnIndex), firstDrawnColumnIndex);
+
+                var firstDrawnRowIndex = Math.Max((int)((offsetY - columnsHeaderFullHeight) / rowFullHeight), 0);
+                var lastDrawnRowIndex = Math.Max(Math.Min((int)((offsetY - columnsHeaderFullHeight + viewHeight) / rowFullHeight), control.Sheet.LastRowIndex), firstDrawnRowIndex);
+
+                Log("firstCol:" + firstDrawnColumnIndex + " lastCol:" + lastDrawnColumnIndex + " firstRow:" + firstDrawnRowIndex + " lastRow:" + lastDrawnRowIndex);
 
                 // header backgrounds
-                drawingContext.DrawRectangle(Brushes.LightGray, null, new Rect(offsetX, headerHeight, rowMargin + offsetX, (control.Sheet.LastRowIndex + 1) * rowHeight));
-                drawingContext.DrawRectangle(Brushes.LightGray, null, new Rect(rowMargin, 0, (control.Sheet.LastColumnIndex + 1) * colWidth, headerHeight));
+                drawingContext.DrawRectangle(Brushes.LightGray, null, new Rect(offsetX, columnsHeaderHeight, rowsHeaderWidth, (control.Sheet.LastRowIndex + 1) * rowHeight));
+                drawingContext.DrawRectangle(Brushes.LightGray, null, new Rect(rowsHeaderWidth, offsetY, (control.Sheet.LastColumnIndex + 1) * colWidth, columnsHeaderHeight));
 
-                var maxWidth = Math.Min(colWidth * (control.Sheet.LastColumnIndex + 1) + rowMargin, RenderSize.Width);
+                var maxWidth = Math.Min(colWidth * (control.Sheet.LastColumnIndex + 1) + rowsHeaderWidth, RenderSize.Width);
                 var maxHeight = Math.Min(rowHeight * (control.Sheet.LastRowIndex + 2), RenderSize.Height);
 
                 // includes col header
@@ -135,61 +149,66 @@ protected override void OnRender(DrawingContext drawingContext)
                     }
                     else
                     {
-                        x = colWidth * i - (colWidth - rowMargin);
+                        x = colWidth * i - (colWidth - rowsHeaderWidth);
                     }
 
-                    drawingContext.DrawLine(pen, new Point(x, 0), new Point(x, maxHeight));
+                    drawingContext.DrawLine(pen, new Point(x, offsetY), new Point(x, maxHeight));
 
                     // draw col name
                     if (i < control.Sheet.LastColumnIndex + 1)
                     {
                         var name = GetExcelColumnName(i);
-                        var formatted = new FormattedText(name, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeFace, fontSize, Brushes.Black, dpi.PixelsPerDip)
+                        var formatted = new FormattedText(name, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeFace, control.FontSize, control.Foreground, dpi.PixelsPerDip)
                         {
-                            MaxTextWidth = rowMargin,
+                            MaxTextWidth = rowsHeaderWidth,
                             MaxLineCount = 1
                         };
 
                         var xoffset = (colWidth - formatted.Width) / 2; // center horizontally
-                        var yoffset = (headerHeight - formatted.Height) / 2; // center vertically
-                        drawingContext.DrawText(formatted, new Point(xoffset + rowMargin + i * colWidth + pen.Thickness, yoffset + pen.Thickness));
+                        var yoffset = offsetY + (columnsHeaderHeight - formatted.Height) / 2; // center vertically
+                        drawingContext.DrawText(formatted, new Point(xoffset + rowsHeaderWidth + i * colWidth + pen.Thickness, yoffset + pen.Thickness));
                     }
                 }
 
                 // includess row margin
                 for (var i = 0; i < control.Sheet.LastRowIndex + 2 + 1; i++)
                 {
                     var y = rowHeight * i;
-                    drawingContext.DrawLine(pen, new Point(0, y), new Point(maxWidth, y));
+                    drawingContext.DrawLine(pen, new Point(offsetX, y), new Point(maxWidth, y));
 
                     // draw row #
                     if (i < control.Sheet.LastRowIndex + 1)
                     {
-                        var formatted = new FormattedText((i + 1).ToString(), CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeFace, fontSize, Brushes.Black, dpi.PixelsPerDip)
+                        var formatted = new FormattedText((i + 1).ToString(), CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeFace, control.FontSize, control.Foreground, dpi.PixelsPerDip)
                         {
-                            MaxTextWidth = rowMargin,
+                            MaxTextWidth = rowsHeaderWidth,
                             MaxLineCount = 1
                         };
 
-                        var xoffset = (rowMargin - formatted.Width) / 2; // center horizontally
+                        var xoffset = offsetX + (rowsHeaderWidth - formatted.Width) / 2; // center horizontally
                         var yoffset = (rowHeight - formatted.Height) / 2; // center vertically
-                        drawingContext.DrawText(formatted, new Point(xoffset + pen.Thickness, headerHeight + rowHeight * i + yoffset + pen.Thickness));
+                        drawingContext.DrawText(formatted, new Point(xoffset + pen.Thickness, columnsHeaderHeight + rowHeight * i + yoffset + pen.Thickness));
                     }
                 }
 
-                foreach (var row in control.Sheet.Rows)
+                for (var i = firstDrawnRowIndex; i <= lastDrawnRowIndex; i++)
                 {
-                    foreach (var cell in row.Cells)
+                    var row = control.Sheet.Rows[i];
+                    for (var j = firstDrawnColumnIndex; j <= lastDrawnColumnIndex; j++)
                     {
+                        if (j >= row.Cells.Count)
+                            continue;
+
+                        var cell = row.Cells[j];
                         var text = string.Format("{0}", cell.Value);
-                        var formatted = new FormattedText(text, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeFace, fontSize, Brushes.Black, dpi.PixelsPerDip)
+                        var formatted = new FormattedText(text, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeFace, control.FontSize, control.Foreground, dpi.PixelsPerDip)
                         {
                             MaxTextWidth = colWidth,
                             MaxLineCount = 1
                         };
 
-                        var y = headerHeight + rowHeight * row.RowIndex;
-                        var x = rowMargin + colWidth * cell.ColumnIndex;
+                        var y = columnsHeaderHeight + rowHeight * row.RowIndex;
+                        var x = rowsHeaderWidth + colWidth * cell.ColumnIndex;
                         var yoffset = (rowHeight - formatted.Height) / 2; // center vertically
                         drawingContext.DrawText(formatted, new Point(x + pen.Thickness, y + yoffset + pen.Thickness));
                     }

SheetReader.Wpf/Themes/Generic.xaml

@@ -14,6 +14,8 @@
                         x:Name="PART_ScrollViewer"
                         Grid.Row="1"
                         Grid.Column="1"
+                        Background="{TemplateBinding Background}"
+                        Foreground="{TemplateBinding Foreground}"
                         HorizontalScrollBarVisibility="Auto"
                         VerticalScrollBarVisibility="Auto" />
                 </ControlTemplate>

SheetReader.Wpf/Utilities/EventProvider.cs

@@ -0,0 +1,44 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.InteropServices;
+using System.Threading;
+
+namespace SheetReader.Wpf.Utilities
+{
+    public sealed class EventProvider : IDisposable
+    {
+        // use WpfTraceSpy to read this https://github.com/smourier/TraceSpy ("ETW messages support")
+        public static EventProvider Default { get; } = new(new Guid("964d4572-adb9-4f3a-8170-fcbecec27467"));
+
+        private long _handle;
+        public Guid Id { get; }
+
+        public EventProvider(Guid id)
+        {
+            Id = id;
+            var hr = EventRegister(id, IntPtr.Zero, IntPtr.Zero, out _handle);
+            if (hr != 0)
+                throw new Win32Exception(hr);
+        }
+
+        public bool WriteMessageEvent(string text, byte level = 0, long keywords = 0) => EventWriteString(_handle, level, keywords, text) == 0;
+
+        public void Dispose()
+        {
+            var handle = Interlocked.Exchange(ref _handle, 0);
+            if (handle != 0)
+            {
+                _ = EventUnregister(handle);
+            }
+        }
+
+        [DllImport("advapi32")]
+        private static extern int EventRegister([MarshalAs(UnmanagedType.LPStruct)] Guid ProviderId, IntPtr EnableCallback, IntPtr CallbackContext, out long RegHandle);
+
+        [DllImport("advapi32")]
+        private static extern int EventUnregister(long RegHandle);
+
+        [DllImport("advapi32")]
+        private static extern int EventWriteString(long RegHandle, byte Level, long Keyword, [MarshalAs(UnmanagedType.LPWStr)] string String);
+    }
+}

SheetReader/Book.cs

@@ -330,7 +330,7 @@ public XlsxSheet(XlsxBook book, XElement element, XmlReader reader)
                 Book = book;
                 Element = element;
                 Reader = reader;
-                Name = element.Attribute("name")?.Value;
+                Name = element.Attribute("name")?.Value!;
                 var state = element.Attribute("state")?.Value;
                 if (state.EqualsIgnoreCase("hidden"))
                 {