Customizing UI with ControlUWP: Techniques & ExamplesUniversal Windows Platform (UWP) applications offer a modern, touch-friendly UI surface across Windows devices. ControlUWP — a term used here to refer to custom and built-in controls in UWP — enables developers to craft interfaces that are visually engaging, accessible, and performant. This article walks through core techniques for customizing UWP controls, shows practical examples, and highlights patterns and tools that speed development.
Why customize controls?
Built-in UWP controls are flexible, but customization is often necessary to:
- Match brand identity (colors, typography, and shapes).
- Improve usability for specific workflows (streamline input, emphasize actions).
- Support accessibility requirements (contrast, keyboard navigation, screen reader hints).
- Optimize performance and responsiveness for different device families.
Fundamental concepts
Before changing visuals or behavior, understand these key UWP concepts:
- Control Template: defines the visual tree of a control. Replacing a ControlTemplate changes how the control is rendered.
- Styles: collections of property setters that can be applied to controls to change appearance (Brushes, FontSize, Padding).
- Visual States: named states (e.g., Normal, PointerOver, Pressed) with Storyboards to animate transitions.
- TemplatedParent and TemplateBinding: link template elements to the control’s properties.
- Resource Dictionaries: centralized storage for styles, brushes, and templates for reuse and theming.
- Composition API: low-level visual layer for high-performance animations and effects.
- XAML vs. Code-behind: prefer declarative XAML for visuals; use code for dynamic adjustments.
Tools and workflow
- Use Visual Studio’s “Edit Template” → “Edit a Copy” to extract default templates for modification.
- Enable Live Visual Tree and Live Property Explorer to inspect running UI.
- Maintain design tokens (colors, spacing) in ResourceDictionaries to support theming.
- Test on multiple device scales and orientations; use simulator and remote device testing.
Styles: quick visual changes
Example: a consistent button style.
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> <SolidColorBrush x:Key="PrimaryBrush" Color="#0078D7"/> <SolidColorBrush x:Key="PrimaryBrushAccent" Color="#005A9E"/> <Style TargetType="Button" x:Key="PrimaryButtonStyle"> <Setter Property="Background" Value="{StaticResource PrimaryBrush}"/> <Setter Property="Foreground" Value="White"/> <Setter Property="Padding" Value="12,6"/> <Setter Property="FontWeight" Value="SemiBold"/> <Setter Property="CornerRadius" Value="6"/> </Style> </ResourceDictionary> Usage:
<Button Style="{StaticResource PrimaryButtonStyle}" Content="Save"/> Control Templates: reshape controls
Replacing a control’s template lets you change structure and visuals. Example: simplified ToggleSwitch template that uses a Grid and ellipse for the thumb.
<ControlTemplate TargetType="ToggleSwitch" x:Key="CustomToggleSwitchTemplate"> <Grid x:Name="RootGrid" Width="80" Height="36" Background="{TemplateBinding Background}"> <Border x:Name="SwitchTrack" CornerRadius="18" Background="{TemplateBinding Background}" /> <Ellipse x:Name="Thumb" Width="30" Height="30" Fill="White" Margin="3"/> </Grid> <ControlTemplate.Triggers> <!-- Use VisualStateManager instead for complex state changes --> </ControlTemplate.Triggers> </ControlTemplate> Attach to control:
<ToggleSwitch Template="{StaticResource CustomToggleSwitchTemplate}" /> For production use, include VisualStateManager to animate Thumb position on IsOn changes.
Visual States and animations
VisualStateManager (VSM) manages state-driven visuals. Example snippet adding states for Normal, PointerOver, and Pressed for a custom button.
<ControlTemplate TargetType="Button"> <Grid x:Name="Root"> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="CommonStates"> <VisualState x:Name="Normal"/> <VisualState x:Name="PointerOver"> <Storyboard> <ColorAnimation Storyboard.TargetName="BackgroundRect" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" To="#106EBE" Duration="0:0:0.15" /> </Storyboard> </VisualState> <VisualState x:Name="Pressed"> <Storyboard> <DoubleAnimation Storyboard.TargetName="ContentPresenter" Storyboard.TargetProperty="Opacity" To="0.6" Duration="0:0:0.08"/> </Storyboard> </VisualState> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Rectangle x:Name="BackgroundRect" Fill="{TemplateBinding Background}" RadiusX="6" RadiusY="6"/> <ContentPresenter x:Name="ContentPresenter" HorizontalAlignment="Center" VerticalAlignment="Center"/> </Grid> </ControlTemplate> Composition API: smooth, performant visuals
For animation-heavy or GPU-accelerated effects, use Windows.UI.Composition (WinUI/Composition). Example: drop shadow using Composition in code-behind.
C# example:
using Windows.UI.Composition; using Microsoft.UI.Xaml.Hosting; // inside a Page or UserControl var compositor = ElementCompositionPreview.GetElementVisual(this).Compositor; var sprite = compositor.CreateSpriteVisual(); var dropShadow = compositor.CreateDropShadow(); dropShadow.BlurRadius = 10f; dropShadow.Color = Windows.UI.Colors.Black; sprite.Shadow = dropShadow; ElementCompositionPreview.SetElementChildVisual(HostBorder, sprite); Replace HostBorder with the XAML element you want shadowed. Composition runs on a separate layer for smooth 60+ FPS animations.
Responsive & adaptive UI
- Use AdaptiveTriggers or x:Phase for loading optimizations.
- RelativePanel, Grid with star sizing, and AdaptiveTrigger-based VisualState changes adapt layout.
- Example: switch from a two-column Grid to a single column under 720px width.
<VisualStateManager.VisualStateGroups> <VisualStateGroup> <VisualState x:Name="NarrowState"> <VisualState.StateTriggers> <AdaptiveTrigger MinWindowWidth="0"/> </VisualState.StateTriggers> <VisualState.Setters> <Setter Target="ContentGrid.ColumnDefinitions[1].Width" Value="0"/> </VisualState.Setters> </VisualState> <VisualState x:Name="WideState"> <VisualState.StateTriggers> <AdaptiveTrigger MinWindowWidth="720"/> </VisualState.StateTriggers> <VisualState.Setters> <Setter Target="ContentGrid.ColumnDefinitions[1].Width" Value="*"/> </VisualState.Setters> </VisualState> </VisualStateGroup> </VisualStateManager.VisualStateGroups> Accessibility
- Honor high contrast and system font size settings by using ThemeResources and system brushes.
- Provide AutomationProperties.Name, HelpText, and IsInAccessibleTree.
- Ensure focus visuals and keyboard navigation (TabIndex, IsTabStop).
Example:
<Button Content="Open" AutomationProperties.Name="Open file" /> Practical examples
- Custom Card control
- Use a UserControl with Shadow via Composition, rounded corners, and content slot via ContentPresenter.
- Provide dependency properties for Elevation and CornerRadius.
- Themed App Shell
- Central ResourceDictionary with AccentBrush, NeutralBrush, and Typography styles.
- Swap resource dictionaries at runtime to implement light/dark or brand themes.
- Animated ListView item
- Use Composition Visuals for item entrance animations; use x:Bind and incremental loading for performance.
Testing and performance tips
- Measure with Visual Studio Profiler and XAML UI Responsiveness tools.
- Reduce Visual Tree depth; prefer Composition over heavy XAML animations when possible.
- Use virtualization (ListView/GridView) for large collections.
- Freeze brushes where possible and reuse brushes from resources.
When to create a custom control vs. user control
- Create a custom Control (derive from Control) when you need templating, theming, or reusability across styles.
- Use a UserControl for composite UI that won’t need templating or styling variations.
Closing notes
Customizing UWP controls involves a balance of visual polish, accessibility, and performance. Start with styles and resource dictionaries, use ControlTemplates and VisualStateManager for deeper changes, and employ the Composition API for high-performance effects. Extract default templates, iterate in small steps, and test across devices and accessibility settings.
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