c# – 如何在MVVM中使用ApplicationCommands

我想使用ApplicationCommands.Cut,复制,粘贴,保存……由于命令路由,键绑定以及某些控件使用它们这一事实,它们看起来很有趣.我理解如何绑定到我的VM上的relay / delegate命令,但我似乎无法理解应用程序命令.我找到了几个旧的答案,但没有其他信息,我有点不愿意遵循这些路线.

这似乎是常见的,但信息似乎非常有限.这通常是如何实现的？ (使用或不使用PRISM,MVVM Light,……)

旧答案：

How to bind ApplicationCommands to a ViewModel但这对我来说使用行为来解决这个问题似乎很奇怪

WPF – Handle an ApplicationCommand in the ViewModel但我不认为MVVM在接受的答案中.

使用旧文章中的附加属性：CommandBindings with MVVM引用另一篇文章.

解决方法

我问了这个问题已经有一段时间了,但看起来很多人都在看它.我最终使用了一个将VM命令列表连接到FrameworkElement的行为.这似乎是最灵活和可重复使用的解决方案.

public class AttachCommandBindingsBehavior : Behavior<FrameworkElement>
{
    public ObservableCollection<CommandBinding> CommandBindings
    {
        get
        {
            return (ObservableCollection<CommandBinding>)GetValue(CommandBindingsProperty);
        }
        set
        {
            SetValue(CommandBindingsProperty,value);
        }
    }
    public static readonly DependencyProperty CommandBindingsProperty = DependencyProperty.Register("CommandBindings",typeof(ObservableCollection<CommandBinding>),typeof(AttachCommandBindingsBehavior),new PropertyMetadata(null,OnCommandBindingsChanged));

    private static void OnCommandBindingsChanged(DependencyObject sender,DependencyPropertyChangedEventArgs e)
    {
        AttachCommandBindingsBehavior attachCommandBindingsBehavior = (AttachCommandBindingsBehavior)sender;

        if (attachCommandBindingsBehavior == null)
            return;

        ObservableCollection<CommandBinding> commandBindings = (ObservableCollection<CommandBinding>)e.NewValue;

        if (commandBindings != null)
        {
            if (attachCommandBindingsBehavior.CommandBindings != null)
                attachCommandBindingsBehavior.CommandBindings.CollectionChanged -= attachCommandBindingsBehavior.CommandBindings_CollectionChanged;

            attachCommandBindingsBehavior.CommandBindings.CollectionChanged += attachCommandBindingsBehavior.CommandBindings_CollectionChanged;
        }
    }

    void CommandBindings_CollectionChanged(object sender,System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        ObservableCollection<CommandBinding> collection = (ObservableCollection<CommandBinding>)sender;

        if (collection != null)
        {
            foreach (CommandBinding commandBinding in collection)
                Associatedobject.CommandBindings.Add(commandBinding);
        }
    }
}

在xaml中,您可以这样做：

<i:Interaction.Behaviors>
    <localBehaviors:AttachCommandBindingsBehavior CommandBindings="{Binding CommandBindings}"/>
</i:Interaction.Behaviors>