Releasing the Image File Locked by BitmapImage in WPF with BitmapCacheOption.OnLoad
An image file shown through BitmapImage cannot be deleted or overwritten. This covers the default caching behavior behind it and the OnLoad fix.
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Technical articles on WPF, XAML, C# and Windows application development.
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Replicating Windows Explorer Sort Order in C# with StrCmpLogicalW and IComparer
The default string sort orders "item10" before "item2". This shows how to reproduce Explorer's natural sort order via StrCmpLogicalW P/Invoke in an IComparer.
Fixing a RelayCommand Whose CanExecute Does Not Update the Button State in WPF
A custom RelayCommand's button stays stuck when CanExecuteChanged is never raised. This compares delegating to RequerySuggested with raising it manually.
Calling TextBox UpdateSource from the View in WPF: Implementation and Pitfalls
Calling GetBindingExpression().UpdateSource() from the View has pitfalls: null returns, bulk updates, wrong direction, and MVVM, grounded in official docs.
Controlling When TextBox Input Reaches the Source with UpdateSourceTrigger in WPF
TextBox.Text defaults to LostFocus, so typed input may never reach the ViewModel. This covers the three UpdateSourceTrigger values, their timing, and pitfalls.
Fixing the Cross-Thread Exception When Updating an ObservableCollection in WPF
Modifying a bound ObservableCollection off the UI thread throws a NotSupportedException from CollectionView affinity. This covers the cause and two fixes.
Hiding the Clear Button on a Fluent-Themed WPF TextBox
How to hide the clear button a Fluent-themed WPF TextBox shows on focus, without changing input behavior, on .NET 10 and .NET 9.
Why a WPF ScrollViewer Does Not Scroll and How to Fix It
A ScrollViewer inside a StackPanel does not scroll because the StackPanel never constrains its height. This covers the cause and the Grid and DockPanel fixes.
Formatting Numbers, Currency, and Dates with Binding.StringFormat in WPF
A practical guide to formatting numbers, currency, and dates with Binding.StringFormat without a converter, including culture and ContentControl constraints.
Key-Based Aggregation Without GroupBy — Dictionary-Backed CountBy, AggregateBy and Index
Implementing CountBy, AggregateBy and Index with direct dictionary accumulation, avoiding the intermediate-grouping allocations of GroupBy.
Expressing SQL Outer Joins in LINQ — Implementing LeftJoin, RightJoin and Shuffle
Implementing LeftJoin, RightJoin and Shuffle on .NET Framework, mapping them to SQL outer joins and covering the IQueryable translation pitfall.
Reading WPF Binding Errors and Diagnosing Them with the Output Window
When a WPF Binding fails silently, Visual Studio logs it as a trace. This article covers reading the message, raising the trace level, and common patterns.
Selector-Free ToDictionary — Designing for Overload Resolution and the notnull Constraint
Recreating the .NET 8 selector-free ToDictionary overloads on .NET Framework as an exercise in overload resolution and notnull constraint design.
Order and OrderDescending by Pure Delegation — A Minimal Polyfill with IOrderedEnumerable Compatibility
A delegation-only polyfill for Order and OrderDescending, focused on ThenBy compatibility via IOrderedEnumerable and runtime-specific sort exceptions.
Replacing GroupBy and Full-Sort Workarounds — Implementing Chunk, MaxBy, MinBy and DistinctBy
Measuring the runtime cost of GroupBy and full-sort workaround idioms, then replacing them with Chunk, MaxBy, MinBy and DistinctBy polyfills.
Designing LINQ Polyfills That Preserve Lazy Evaluation — Implementing Append, Prepend, TakeLast and SkipLast
Three design principles for hand-rolled LINQ polyfills, demonstrated through the Append, Prepend, TakeLast and SkipLast implementations.
How to Reset DataGrid Sorting in WPF
Practical ways to reset WPF DataGrid sorting, including explicit clearing, Sorting-event control, CollectionView handling, and a reusable Behavior.
C# Operators and Initialization Syntax by Version
A version-by-version guide to C# operators and initialization syntax, with guidance for .NET Framework compatibility and language-version constraints.
C# 14 Extension Members on Static Classes: Static Members Only
A C# 14 extension block can target a static class such as Directory, but only static members can be added. Instance members are rejected with CS0721 or CS930...
Why StaticResource Changes Are Not Reflected in WPF and How to Fix It
StaticResource resolves its value at XAML load time, so runtime changes have no effect. Use DynamicResource when the value must update at runtime.
Why WPF Slows Down with Many Labels and When to Switch to TextBlock
This article explains why rendering slows down when many WPF Labels are used and provides practical criteria for replacing them with TextBlock.
Why WPF Label Hides Underscores and How to Fix It
When a string containing an underscore (_) is set on a WPF Label, the character disappears from the screen. This article explains the cause and three ways to...
Switching Controls Between Display and Edit Modes in WPF DataGrid Cells
Use DataGridTemplateColumn with CellTemplate and CellEditingTemplate to separate display UI from editing UI in WPF DataGrid.
Fixing a WPF Tray ContextMenu That Does Not Close on Focus Loss
This article explains how TreePaste resolved a tray ContextMenu that stayed visible until an item was clicked by combining StaysOpen=false with SetForeground...
Applying Fluent Design in WPF Without Extra Libraries
This article explains how to apply Fluent styling in WPF using only built-in features, with App.xaml theme setup and SystemColors-based color tracking.
How to Display Selectable, Copyable Read-Only Text in WPF
Learn how to use a read-only TextBox as a TextBlock replacement in WPF so text remains selectable and copyable without allowing edits.
WPF ComboBox ItemsSource Binding Patterns and Selected Value Retrieval
The correct combination of DisplayMemberPath, SelectedItem, SelectedValue, and SelectedValuePath depends on the element type bound to ItemsSource. This artic...
How to Prevent SelectedItems from Appearing Lost in a Virtualized WPF ListBox
Why ListBox selection appears to vanish under UI virtualization, and how an IsSelected-based MVVM pattern keeps it stable, including Shift-range selection.
How to Implement DataGrid Sorting in WPF
Learn the basics of DataGrid sorting and practical implementation patterns for real-world WPF applications.
Customising the DatePicker Display Format in WPF
A practical guide to changing the date display format of WPF DatePicker from XAML, code-behind, and a value converter.