在MVVM Light 5.2.0.37222中找不到GalaSoft.MvvvmLight.CommandWpf命名空

我刚刚尝试将我的一个WPF项目从MVVM Light 4.2.30更新到5.2。在那之后，我注意到我的RelayCommands不再激发他们的CanExecute方法。

经过快速搜索，我找到了几篇文章，解释了这个问题，并建议使用GalaSoft.MvvmLight.CommandWpf命名空间而不是GalaSoft.MvvmLight.Command。但是，我找不到GalaSoft.MvvmLight.CommandWpf命名空间。当我在Visual Studio的"对象浏览器"中查看GalaSoft.MvvVMAlaSoft.MvvmLight.dll时，我也找不到这个命名空间。

除了我，似乎没有其他人有这个问题——你知道我做错了什么吗？

更新：

我创建了一个小的示例项目，展示了我目前如何在MVVM light:的4.2.30版本中使用RelayCommands及其CanExecute方法

public class ViewModel : ViewModelBase
{
    private bool _isReadOnly = false;
    public ViewModel ()
    {
        this.DoSomethingCommand = new RelayCommand(DoSomething, CanDoSomething);
    }
    public bool IsReadOnly
    {
        get
        {
            return _isReadOnly;
        }
        set
        {
            _isReadOnly = value;
            this.RaisePropertyChanged("IsReadOnly");
            // With MVVMLight 4.2.30.23246 I did not need to call the RaiseCanExecuteChanged on any of my RelayCommands
            // DoSomethingCommand.RaiseCanExecuteChanged(); 
        }
    }
    public RelayCommand DoSomethingCommand { get; set; }
    private bool  CanDoSomething()
    {
        return !this.IsReadOnly;
    }
    private void DoSomething()
    {
        MessageBox.Show("Let's break the MVVM idea...");
    }
}

视图的XAML代码为：

<Window x:Class="MVVMLight5.2CanExecuteTest.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:MVVMLight5._2CanExecuteTest"
    mc:Ignorable="d"
    Title="Test" Height="150" Width="200">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <CheckBox HorizontalAlignment="Center" Grid.Row="0" Grid.Column="0" Content="Is read only" IsChecked="{Binding IsReadOnly, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
    <Button Grid.Row="1" Grid.Column="0" Content="Break me" Command="{Binding DoSomethingCommand}"/>
</Grid>

我的目标是，如果我在视图中有一个使用"DoSomethingCommand"作为命令的按钮，那么当我的IsReadOnly属性设置为false时，该按钮应该被禁用。当使用MVVM灯4.2.30时，到目前为止，这没有任何额外的功能，但在MVVM灯5.2中，我需要添加DoSomethingCommand.RiseCanExecuteChanged（）；以使该按钮在视图中禁用。

我能用新的MVVM轻框架以某种方式获得旧的行为吗？

namespace GalaSoft.MvvmLight.Command
{
    /// <omitted, see below>
    public class RelayCommand<T> : ICommand
    {
        private readonly WeakAction<T> _execute;
        private readonly WeakFunc<T, bool> _canExecute;
        /// <summary>
        /// Occurs when changes occur that affect whether the command should execute.
        /// 
        /// </summary>
        public event EventHandler CanExecuteChanged;

namespace GalaSoft.MvvmLight.Command
{
    /// <omitted, see below>
    public class RelayCommand<T> : ICommand
    {
        private readonly WeakAction<T> _execute;
        private readonly WeakFunc<T, bool> _canExecute;
        /// <summary>
        /// Occurs when changes occur that affect whether the command should execute.
        /// 
        /// </summary>
        public event EventHandler CanExecuteChanged
        {
            add
            {
                if (this._canExecute == null)
                    return;
                CommandManager.RequerySuggested += value;
            }
            remove
            {
                if (this._canExecute == null)
                    return;
                CommandManager.RequerySuggested -= value;
            }
        }