In SimpleToDoList second run, error "Unable to resolve type" pops out

[spinningwatt]

Describe the bug

I follow the SimpleToDoList tutorial and encounter an error at "second run". I added code below into my MainWindow.axaml file:

<ItemsControl ItemsSource="{Binding ToDoItems}">
    <ItemsControl.ItemTemplate>
        <!--  The ItemTemplate defines how each item should be represented  -->
        <!--  Our Item will be represented by a CheckBox and a Delete-Button  -->
        <DataTemplate DataType="vm:ToDoItemViewModel">
            <Grid ColumnDefinitions="*, Auto">
                <CheckBox Content="{Binding Content}"
                          IsChecked="{Binding IsChecked}" />

                <!--  Note how we use the Root-Grid to get the MainViewModel here. As we use compiled bindings we have to cast the DataContext  -->
                <Button Command="{Binding #Root.((vm:MainViewModel)DataContext).RemoveItemCommand}"
                        CommandParameter="{Binding .}"
                        Grid.Column="1">
                    Delete
                </Button>
            </Grid>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

Then, full MainWindow.axaml file is:

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="using:AvaloniaTodo.ViewModels"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:views="clr-namespace:AvaloniaTodo.Views"
        mc:Ignorable="d" d:DesignWidth="200" d:DesignHeight="450"
        x:Class="AvaloniaTodo.Views.MainWindow"
        Icon="/Assets/avalonia-logo.ico"
        Title="AvaloniaTodo">
		<!-- We give a name to the root grid in order to access it later -->
		<Grid RowDefinitions="Auto, *, Auto"
			  x:Name="Root">

			<!-- This is our title text block.  -->
			<TextBlock Text="ToDo List App" />

			<ScrollViewer Grid.Row="1">
				<!-- This ItemsControl show all added ToDoItems. -->
				<!-- It needs to be placed inside a ScrollViewer because other than a ListBox it has not its own -->
				<ItemsControl ItemsSource="{Binding ToDoItems}">
					<ItemsControl.ItemTemplate>
						<!--  The ItemTemplate defines how each item should be represented  -->
						<!--  Our Item will be represented by a CheckBox and a Delete-Button  -->
						<DataTemplate DataType="vm:ToDoItemViewModel">
							<Grid ColumnDefinitions="*, Auto">
								<CheckBox Content="{Binding Content}"
										  IsChecked="{Binding IsChecked}" />

								<!--  Note how we use the Root-Grid to get the MainViewModel here. As we use compiled bindings we have to cast the DataContext  -->
								<Button Command="{Binding #Root.((vm:MainViewModel)DataContext).RemoveItemCommand}"
										CommandParameter="{Binding .}"
										Grid.Column="1">
									Delete
								</Button>
							</Grid>
						</DataTemplate>
					</ItemsControl.ItemTemplate>
				</ItemsControl>
			</ScrollViewer>

			<!-- This TextBox can be used to add new ToDoItems -->
			<TextBox Grid.Row="2"
					 Text="{Binding NewItemContent}"
					 Watermark="Add a new Item">
				<TextBox.InnerRightContent>
					<Button Command="{Binding AddItemCommand}" >
						Add
						<!-- <PathIcon Data="{DynamicResource AcceptIconData}" Foreground="Green" /> -->
					</Button>
				</TextBox.InnerRightContent>
				<!--  KeyBindings allow us to define keyboard gestures  -->
				<TextBox.KeyBindings>
					<KeyBinding Command="{Binding AddItemCommand}" Gesture="Enter" />
				</TextBox.KeyBindings>
			</TextBox>
		</Grid>
</Window>

When I click button "add", there's an error:

Unable to resolve type vm:MainViewModel from any of the following locations:

Sample affected

https://github.com/AvaloniaUI/Avalonia.Samples/tree/main/src/Avalonia.Samples/CompleteApps/SimpleToDoList

Proposed solution

It should be able to add a new todo item into the list.

Screenshots

[timunie]

Hey @spinningwatt depending on the IDE and template used to create your project, the name of the MainViewModel may be MainViewModel or MainWindowViewModel. Make sure it matches on your side.

[spinningwatt]

Hey @timunie , I make sure there is a MainViewModel.cs file in my project.

[timunie]

Please delete bin and obj folders and upload the code to GitHub. Preferably to a new repo and share the link or if that's not working for you via zip file here. Will take a look latest in January.

Something is screwed but I don't see it rn.