CheckBoxDemo

Instruction file imported from JDKoll1982/MTM_Waitlist (.github/instructions/demos/BasicInput/CheckBoxDemo.instructions.md). Copyright stays with the author.

CheckBox

What it teaches

An independent on/off choice. Use CheckBox for multiple selections and RadioButton when exactly one applies.

How the demo is built

The page is a UserControl at BasicInput/CheckBoxDemo.xaml, paired with CheckBoxDemo.xaml.cs. The shell hosts it inside Shell/DemoPage.xaml, which also shows both files verbatim — the snippet viewer reads the same source the app compiles, so what is displayed is always what runs.

Layout. Root UserControl with 7 element(s).

Named elements the code-behind touches: TelemetryCheck, StatusText.

Wired in XAML: OnCheckChanged(), OnThreeStateChanged().

Code-behind. Handlers OnCheckChanged(), OnThreeStateChanged(). 32 line(s), including the comments that record what the control does that the docs do not say.

Anything the demo cannot show is explained on the page rather than faked: the same rules the rest of the repo follows are in .github/instructions/winui3-api-rules.instructions.md.

MTM use case

MTM_Receiving_Application › Receiving › quick entry

The operator scans a part label, types a quantity and posts the receipt. Every action on that screen is a button, a drop-down or a toggle, and the disabled states are the guard that stops a receipt being posted before a dunnage type and quantity are both valid.

Schema this mirrors: receiving_history, receiving_package_types, dunnage_parts. Sample data for the page comes from src/WinUI3LearningLab.Core/LabData.cs — part numbers, bins, dunnage types and work orders, never Item 1 or John Doe.

Gotchas

• IsChecked is bool? and IsThreeState enables the indeterminate state used for 'mixed' parent settings.
• The clickable area includes the label, so keep Content short and put long explanations in a separate TextBlock.
• Checked and Unchecked do not fire in a predictable order during initialization — do not rely on them for setup.

Try this

• Run WinUI3LearningLab.App.exe --demo check-box. The page shows CheckBoxDemo.xaml and CheckBoxDemo.xaml.cs beside the live demo, so the next edit can be made against something already running.
• Change one value in the XAML and rebuild; the snippet viewer re-reads the file, so what is shown stays the code that compiled.

Documentation

• Microsoft.UI.Xaml.Controls.CheckBox
• WinUI 3 API rules for this repo
• Design system

Generated from DemoCatalog by --export-instructions. Do not edit by hand: change the descriptor in src/WinUI3LearningLab.Core/Catalog/BasicInput.cs or the demo source, then regenerate.