BindableReadOnlyProp

Simple Usage

Similar to BindableProp, BindableReadOnlyProp is used to create a bindable property with a read-only property. Here's how you can use it:

MainPage.xaml.cs

namespace MauiApp1;

public partial class MainPage : ContentPage
{
    [BindableReadOnlyProp]
    private string _pageType = "Portrait";
    
    public MainPage()
    {
        InitializeComponent();
    }

    protected override void OnSizeAllocated(double width, double height)
    {
        PageType = height > width ? "Portrait" : "Landscape";
        base.OnSizeAllocated(width, height);
    }
}

MauiApp1.MainPage.g.cs

#pragma warning disable

// <auto-generated/>
using BindableProps;

namespace MauiApp1
{
    public partial class MainPage
    {

        public  static readonly BindablePropertyKey PageTypePropertyKey = BindableProperty.CreateReadOnly(
            nameof(PageType),
            typeof(string),
            typeof(MainPage),
            "Portrait",
            (BindingMode)0,
            null,
            (bindable, oldValue, newValue) => 
                        ((MainPage)bindable).PageType = (string)newValue,
            null,
            null,
            null
        );

        public  static readonly BindableProperty PageTypeProperty = PageTypePropertyKey.BindableProperty;

        public  string PageType
        {
            get => _pageType;
            private set 
            { 
                OnPropertyChanging(nameof(PageType));

                _pageType = value;
                SetValue(MainPage.PageTypePropertyKey, _pageType);

                OnPropertyChanged(nameof(PageType));
            }
        }

    }
}

warning

Notice the private set in MauiApp1.MainPage.g.cs. This is the read-only property that you can set only within the class.

In this example, the PageType property is set based on the screen width and height.

MainPage.xaml

<?xml version="1.0" encoding="utf-8"?>

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Name="Self"
             x:Class="MauiApp1.MainPage">

    <ScrollView>
        <VerticalStackLayout
            Padding="30,0"
            Spacing="25">
            <Label
                Text="{x:Binding PageType, Source={x:Reference Self}}"
                FontSize="30"
                HorizontalOptions="Center" />
        </VerticalStackLayout>
    </ScrollView>

</ContentPage>