Hot Design Troubleshooting

This guide lists known issues and troubleshooting steps for Hot Design. If you encounter a problem not listed here, please file a bug report.

Known issues

All Platforms

Configuring Automatic Hot Design Launch for Automation

  • Description: By default, Hot Design launches automatically in Debug mode. For CI, App MCP, and other automation scenarios, this behavior needs to be disabled.

  • Solution: You can control launch behavior using either an environment variable or an MSBuild property. When set, these take precedence over the launchHotDesignOnStart parameter in code.

    Option 1: Environment Variable (highest priority, set at runtime)

    Set the environment variable UNO_HOTDESIGN_LAUNCH to control launch behavior. Set it to false or 0 to disable automatic launch, or true or 1 to enable it.

    # Disable automatic launch (recommended for automation)
# On Windows (PowerShell)
$env:UNO_HOTDESIGN_LAUNCH = "false"

# On Windows (Command Prompt)
set UNO_HOTDESIGN_LAUNCH=false

# On macOS/Linux
export UNO_HOTDESIGN_LAUNCH=false

# Enable automatic launch
export UNO_HOTDESIGN_LAUNCH=true  # or "1"

    Option 2: MSBuild Property (set in project file)

    Add the UnoHotDesignLaunch property to your project file (.csproj):

    <PropertyGroup>
  <!-- Disable Hot Design automatic launch -->
  <UnoHotDesignLaunch>false</UnoHotDesignLaunch>
</PropertyGroup>

    Or enable it:

    <PropertyGroup>
  <!-- Enable Hot Design automatic launch -->
  <UnoHotDesignLaunch>true</UnoHotDesignLaunch>
</PropertyGroup>

    Priority Order:

    1. Environment variable UNO_HOTDESIGN_LAUNCH (highest priority)
    2. MSBuild property UnoHotDesignLaunch
    3. Code parameter launchHotDesignOnStart in UseStudio() call

Multi-Window Support Unavailable

  • Description: Hot Design does not currently support multiple windows.
  • Workaround: Define the UI for additional windows manually in code.

Editing Flyouts (Limited Support)

  • Description: Editing Flyouts is supported but limited. Nested Flyouts are not supported.
  • Related Discussion: #7
  • Workaround: For nested Flyouts, define them manually in code or use the Complex Editor in the Properties panel.

Editing ContentDialogs

  • Description: Editing ContentDialog is not currently supported.
  • Related Discussion: #7
  • Workaround: Define dialogs manually in code.

Inline Elements in TextBlock Not Recognized

  • Description: Inline elements in <TextBlock> are only recognized when declared inside <TextBlock.Inlines>.
  • Workaround: Always wrap inline content inside <TextBlock.Inlines>…</TextBlock.Inlines>.

Markup Extensions (Basic Support Only)

  • Description: Markup Extension values can be viewed and cleared in the Properties panel, but editing is limited.
  • Workaround:
    • Use Reset to clear and reopen the property flyout before editing.
    • Enter Interactive Mode or restart Hot Design to preview changes.
    • For advanced editing, modify directly in XAML.

WebAssembly

Performance When Debugging

  • Description: When debugging on WebAssembly, Hot Design may perform more slowly.
  • Workaround: Run the app without the debugger attached for smoother performance.

Android

Emulator Session Switching

  • Description: If Hot Design is used in Application A and the app is closed in the emulator, launching Application B afterward will cause Hot Design to not function correctly.
  • Workaround:
    1. Open Solution B in your IDE (e.g., Visual Studio).
    2. Run the app again in the emulator.
    3. If the issue persists, fully close and restart the emulator.

Contributions and Feedback

If you encounter recurring issues or specific scenarios not covered in this guide, please consider the following:

Your input matters, it helps us continuously improve the Hot Design experience for everyone.