ViewModelBase コマンドにバインドされた WPF ボタンが機能しないのはなぜですか?

<code class="language-xml"><Button Content="Click Me" Command="{Binding ClickCommand}" /></code>

<code class="language-csharp">public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModelBase();
    }
}</code>

<code class="language-csharp">public class ViewModelBase : INotifyPropertyChanged // 添加INotifyPropertyChanged接口
{
    public event PropertyChangedEventHandler PropertyChanged;

    private ICommand _clickCommand;
    public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), () => CanExecute));
        }
    }

    public bool CanExecute
    {
        get
        {
            // 检查命令是否可执行
            return true;
        }
    }

    public void MyAction()
    {
        // 按钮点击时执行的操作
        MessageBox.Show("Button Clicked!");
    }

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}</code>

<code class="language-csharp">public class CommandHandler : ICommand
{
    private Action _action;
    private Func<bool> _canExecute;

    public CommandHandler(Action action, Func<bool> canExecute)
    {
        _action = action;
        _canExecute = canExecute;
    }

    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    public bool CanExecute(object parameter)
    {
        return _canExecute?.Invoke() ?? false; //处理空值
    }

    public void Execute(object parameter)
    {
        _action?.Invoke(); //处理空值
    }
}</code>

<code class="language-csharp">public AttributeView()
{
    InitializeComponent(); // 添加初始化组件
    DataInitialization = new CommandHandler(DataInitializationAction, CanExecuteReinitialize);
}</code>