I'm having a problem setting up compiled binding in my maui content page

Question

I found an article on Compiled Binding and tried to follow it exactly. My XAML file looks something like this:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:viewmodel="clr-namespace:LockAndKeyMaui.ViewModels"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="LockAndKeyMaui.Views.MainPage"
             x:DataType="viewmodel:MainViewModel">

    <Grid RowDefinitions="85,Auto,Auto,Auto"
          ColumnDefinitions="240,5,*"
          BackgroundColor="DarkGreen">
        <Image Source="password_info.png"
               Aspect="Fill" Grid.ColumnSpan="3"/>

        <Label Text="Group Select"
               TextColor="Yellow" FontSize="Medium"
               FontAttributes="Bold" HorizontalTextAlignment="Center"
               Margin="0,30,0,0" Grid.Row="1"/>

        <BoxView Color="Aquamarine"
                 WidthRequest="2"
                 HorizontalOptions="Center"
                 Grid.Row="1" Grid.Column="1"
                 Grid.RowSpan="3"/>

        <Label Text="Password List"
               TextColor="Yellow" FontSize="Medium"
               FontAttributes="Bold" Margin="20,30,0,0"
               Grid.Row="1" Grid.Column="2"/>

        <HorizontalStackLayout
            HorizontalOptions="End"
            Margin="0,30,20,0" Grid.Row="1"
            Grid.Column="2">
            <Label Text="Owner:"
                   TextColor="Yellow" FontSize="Medium"
                   FontAttributes="Bold" TextDecorations="Underline"/>
            <Label Text="{Binding Ownr}"
                   TextColor="White" FontSize="Small"
                    VerticalTextAlignment="Center" Margin="15,0,0,0"/>
        </HorizontalStackLayout>

    </Grid>
</ContentPage>

Its code-behind looks like this:

using LockAndKeyMaui.ViewModels;

namespace LockAndKeyMaui.Views;

public partial class MainPage : ContentPage
{
    public MainPage(MainViewModel vm)
    {
        InitializeComponent();
        BindingContext = vm;
    }
}

And when I try to run the program, I get this:

#if DEBUG && !DISABLE_XAML_GENERATED_BINDING_DEBUG_OUTPUT DebugSettings.BindingFailed += (sender, args) => { global::System.Diagnostics.Debug.WriteLine(args.Message); }; #endif #if DEBUG && !DISABLE_XAML_GENERATED_RESOURCE_REFERENCE_DEBUG_OUTPUT DebugSettings.XamlResourceReferenceFailed += (sender, args) => { global::System.Diagnostics.Debug.WriteLine(args.Message); }; #endif #if DEBUG && !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION UnhandledException += (sender, e) => { if (global::System.Diagnostics.Debugger.IsAttached) global::System.Diagnostics.Debugger.Break(); }; #endif } } }

Which is from the App.g.i.cs file.

So what am I missing? How do I fix this?

Answer 1

When I setup the compiled data binding as per This article, I forgot to register the view model file in the MauiProgram.cs file. So adding the line

builder.Services.AddSingleton<MainViewModel>();

to the MauiProgram.cs file solved the problem.