From maui-skills
Guides .NET MAUI XAML data bindings including compiled bindings, value converters, binding modes, multi-binding, relative bindings, BindingContext, and MVVM with INotifyPropertyChanged.
How this skill is triggered — by the user, by Claude, or both
Slash command
/maui-skills:maui-data-bindingThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Set `Mode` explicitly **only** when overriding the default. Most properties already have the right default:
Set Mode explicitly only when overriding the default. Most properties already have the right default:
<!-- ✅ Defaults — omit Mode -->
<Label Text="{Binding Score}" /> <!-- OneWay is the default -->
<Entry Text="{Binding UserName}" /> <!-- TwoWay is the default -->
<Switch IsToggled="{Binding DarkMode}" /> <!-- TwoWay is the default -->
<!-- ✅ Override when needed -->
<Label Text="{Binding Title, Mode=OneTime}" />
<Entry Text="{Binding SearchQuery, Mode=OneWayToSource}" />
<!-- ❌ Redundant — just noise -->
<Label Text="{Binding Score, Mode=OneWay}" />
<Entry Text="{Binding UserName, Mode=TwoWay}" />
Compiled bindings are 8–20× faster than reflection-based bindings. Enable with x:DataType.
Place x:DataType only where BindingContext is set:
BindingContext.Do not scatter x:DataType on child elements. Adding x:DataType="x:Object" on children to "escape" compiled bindings is an anti-pattern — it disables compile-time checking and reintroduces reflection.
<!-- ✅ Correct: x:DataType only where BindingContext is set -->
<ContentPage x:DataType="vm:MainViewModel">
<StackLayout>
<Label Text="{Binding Title}" />
<Slider Value="{Binding Progress}" />
</StackLayout>
</ContentPage>
<!-- ❌ Wrong: x:DataType scattered on children -->
<ContentPage x:DataType="vm:MainViewModel">
<StackLayout>
<Label Text="{Binding Title}" />
<Slider x:DataType="x:Object" Value="{Binding Progress}" />
</StackLayout>
</ContentPage>
DataTemplate always needs its own x:DataType:
<CollectionView ItemsSource="{Binding People}">
<CollectionView.ItemTemplate>
<DataTemplate x:DataType="model:Person">
<Label Text="{Binding FullName}" />
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
| Warning | Meaning |
|---|---|
| XC0022 | Binding path not found on the declared x:DataType |
| XC0023 | Property is not bindable |
| XC0024 | x:DataType type not found |
| XC0025 | Binding used without x:DataType (non-compiled fallback) |
<WarningsAsErrors>XC0022;XC0025</WarningsAsErrors>
Fully AOT-safe, no reflection:
label.SetBinding(Label.TextProperty,
static (PersonViewModel vm) => vm.FullName);
entry.SetBinding(Entry.TextProperty,
static (PersonViewModel vm) => vm.Age,
mode: BindingMode.TwoWay,
converter: new IntToStringConverter());
MAUI automatically marshals PropertyChanged to the UI thread — you can raise it from any thread. However, direct ObservableCollection mutations (Add/Remove) from background threads may still crash:
// ✅ Safe for PropertyChanged
await Task.Run(() => Items = LoadData());
// ⚠️ ObservableCollection.Add — dispatch to UI thread
MainThread.BeginInvokeOnMainThread(() => Items.Add(newItem));
x:DataType or code SetBinding with lambdas) are trimmer- and AOT-safe.OneTime mode for truly static data to skip change-tracking registration.npx claudepluginhub davidortinau/maui-skills --plugin maui-skillsGuides .NET MAUI performance optimization including profiling with dotnet-trace, compiled bindings, layout efficiency, image optimization, trimming, NativeAOT, and startup improvements. For slow apps, large sizes, or poor responsiveness.
Building .NET MAUI apps. Project structure, XAML/MVVM, platform services, current caveats.
Converts long inline XAML bindings to Property Element Syntax for better readability. Use when expressions exceed 100 characters, include nested RelativeSource, MultiBinding, or validation rules.