❔ Using mvvm toolkit- Why my view has no access to my command?

        <Button x:Name="oneButton"
                Command="{Binding CalculateAndSave}"
                Click="NumberButton_Click"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

        <Button x:Name="oneButton"
                Command="{Binding CalculateAndSave}"
                Click="NumberButton_Click"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

    public partial class MainWindow : Window
    {
        double lastNumber, result;
        SelectedOperator selectedOperator;
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new CalculatorVM();

            acButton.Click += AcButton_Click;
            negativeButton.Click += NegativeButton_Click;
            percentageButton.Click += PercentageButton_Click;
            equalButton.Click += EqualButton_Click;
        }

    public partial class MainWindow : Window
    {
        double lastNumber, result;
        SelectedOperator selectedOperator;
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new CalculatorVM();

            acButton.Click += AcButton_Click;
            negativeButton.Click += NegativeButton_Click;
            percentageButton.Click += PercentageButton_Click;
            equalButton.Click += EqualButton_Click;
        }

<Button x:Name="oneButton"
                Command="{Binding CalculateAndSaveCommand}"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

<Button x:Name="oneButton"
                Command="{Binding CalculateAndSaveCommand}"
                Style="{StaticResource numberButtonsStyle}"
                Content="1"
                Grid.Row="4"/>

    public partial class CalculatorVM: ObservableObject

    public partial class CalculatorVM: ObservableObject

public RelayCommand CalculateAndSaveCommand { get; set; }
        public CalculatorVM()
        {
            CalculateAndSaveCommand  = new RelayCommand(CalculateAndSave);
        }

public RelayCommand CalculateAndSaveCommand { get; set; }
        public CalculatorVM()
        {
            CalculateAndSaveCommand  = new RelayCommand(CalculateAndSave);
        }

in the solution explorer in visual studio, expand your Calculator project, right click "References" and select "Migrate packages.config to PackageReference"
also that, you need to set the LangVersion of the Project to at least 8..

in the solution explorer in visual studio, expand your Calculator project, right click "References" and select "Migrate packages.config to PackageReference"
also that, you need to set the LangVersion of the Project to at least 8..