🔗 What Are Bindable Properties in .NET MAUI?

✅ What Is a Bindable Property?

A bindable property is not just a property, it’s a construct that integrates with the MAUI/XAML binding engine. It allows:

• Data binding between UI and view models.

• Change notification, so the UI updates when the data changes.

• Reusability of custom controls by exposing properties to other developers or views.

When to Use Them and Why They're Essential

In .NET MAUI, bindable properties are a special type of property designed to support data binding, styling, and property change notifications. While many built-in controls like Button, Entry, and Label already include bindable properties (like Text, Color, or Command), when you're creating custom UI controls like a custom-styled entry or reusable button you'll need to define your own bindable properties to make those controls work seamlessly in XAML and MVVM.

🧰 Why Do We Use Bindable Properties?

You must use bindable properties when:

• You're creating your own controls (like a custom button or entry) and want to expose properties such as Text, Command, or Placeholder to the outside world.

• The base control doesn’t already expose a bindable property you need (e.g., if you're building a new control from scratch or wrapping an existing native view).

• You want your property to support XAML data binding, styles, animations, and change tracking.

• You're working in an MVVM architecture, where separation between UI and logic is key.

👇 Example: Creating a Bindable Text Property in a Custom Entry

Let’s say we’re creating a custom entry control (Customentry) and want to make its Text bindable.

public static readonly BindableProperty TextProperty = BindableProperty.Create(
    propertyName: nameof(Text),
    returnType: typeof(string),
    declaringType: typeof(OrangeEntry),
    defaultValue: null,
    defaultBindingMode: BindingMode.TwoWay);

public string Text
{
    get => (string)GetValue(TextProperty);
    set => SetValue(TextProperty, value);
}

BindableProperty.Create(...) sets up the property with binding support.

The Text property wraps the bindable backing field using GetValue() and SetValue().

💡 Why This Is Important

Framework-provided controls (like Entry, Label, Button) already define bindable properties internally. But when building your own control, like a custom-styled entry or reusable component, you must define your own bindable properties to expose those values to the UI and support binding.

Without defining bindable properties:

• You can't bind values to or from XAML (e.g., Text="{Binding ...}" won’t work).

• You lose support for MVVM, styles, and design-time data.

• The control becomes hard to reuse and tightly coupled to specific logic.

🧪 XAML Usage of Bindable Property in Custom Control

Here’s how you’d bind the Text property in XAML:

<Border Style="{StaticResource CustomBorder}">
<Entry x:Name="txtEntry"
       Grid.Column="1"
       ios:Entry.CursorColor="White"
       Style="{StaticResource WhiteLargeEntryStyle}"
       TextChanged="OnEntryTextChanged"
       IsSpellCheckEnabled="True"
       IsTextPredictionEnabled="True"
       ClearButtonVisibility="WhileEditing"
       ReturnType="Done"
       Text="{Binding Source={x:Reference this}, Path=Text}"
       Placeholder="{Binding Source={x:Reference this}, Path=Placeholder}" />
</Border>

The key here is:

• Text="{Binding ...}" works only because Text is a bindable property.

• Without defining it via BindableProperty.Create(...), this binding would silently fail or do nothing.

🏁 Summary

✨ Final Thoughts

If you're creating your own UI controls in .NET MAUI and want them to support binding you need bindable properties. They’re not just a convenience they are essential to building scalable, maintainable, and reusable components.

By mastering bindable properties, you unlock the full power of the MAUI UI framework and clean MVVM architecture.