据我所知，有些动作会根据行被禁用或启用，所以在单个 ContextMenu 用于 DataGrid.

As far as I know, some of the actions will be disabled or enabled depending on the row, so there is no point in a single ContextMenu for a DataGrid.

我有一个行级上下文菜单的示例.

I have an example of the row-level context menu.

<UserControl.Resources>
    <ContextMenu  x:Key="RowMenu" DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
        <MenuItem Header="Edit" Command="{Binding EditCommand}"/>
    </ContextMenu>
    <Style x:Key="DefaultRowStyle" TargetType="{x:Type DataGridRow}">
        <Setter Property="ContextMenu" Value="{StaticResource RowMenu}" />
    </Style>
</UserControl.Resources>

<DataGrid RowStyle="{StaticResource DefaultRowStyle}"/>

DataGrid 必须使用命令绑定到视图模型列表:

The DataGrid must have a binding to a list of view models with commands:

public class ItemModel
{
    public ItemModel()
    {
        this.EditCommand = new SimpleCommand 
        { 
            ExecuteDelegate = _ => MessageBox.Show("Execute"), 
            CanExecuteDelegate = _ => this.Id == 1 
        };
    }
    public int Id { get; set; }
    public string Title { get; set; }
    public ICommand EditCommand { get; set; }
}

上下文菜单是在 UserControl 的资源集合中创建的，我认为只有一个对象通过引用而不是通过值与数据网格行连接.

The context menu is created in the resources collection of the UserControl and I think there is only one object which is connected with datagrid rows by reference, not by value.

这是 MainViewModel 中 Command 的另一个 ContextMenu 示例.我想 DataGrid 有一个正确的视图模型作为 DataContext，CommandParameter 属性也必须放在 Command 属性之前:

Here is another example of ContextMenu for a Command inside a MainViewModel. I suppose that DataGrid has a correct view model as the DataContext, also the CommandParameter attribute must be placed before the Command attribute:

    <ContextMenu  x:Key="RowMenu" DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
        <MenuItem Header="Edit" CommandParameter="{Binding}"
                  Command="{Binding DataContext.DataGridActionCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=DataGrid}}" />
    </ContextMenu>

型号:

public class MainViewModel
{
    public MainViewModel()
    {
        this.DataGridActionCommand = new DelegateCommand<ItemModel>(m => MessageBox.Show(m.Title), m => m != null && m.Id != 2);
    }

    public DelegateCommand<ItemModel> DataGridActionCommand { get; set; }
    public List<ItemModel> Items { get; set; }
}

public class ItemModel
{
    public int Id { get; set; }
    public string Title { get; set; }
}

但是存在一个问题，如果 CanExecute 返回 false，MenuItem 不会显示为禁用项.可能的解决方法是在 ItemModel 中使用 ParentModel 属性，但它与第一​​个解决方案没有太大区别.以下是上述解决方案的示例:

But there is a problem that MenuItem isn't displayed as a disabled item if CanExecute returns false. The possible workaround is using a ParentModel property inside the ItemModel, but it doesn't differ much from the first solution. Here is example of above-described solution:

public class ItemModel
{
    public int Id { get; set; }
    public string Title { get; set; }
    public MainViewModel ParentViewModel { get; set; }
}

//Somewhere in the code-behind, create the main view model 
//and force child items to use this model as a parent model
var mainModel = new MainViewModel { Items = items.Select(item => new ItemViewModel(item, mainModel)).ToList()};

XAML 中的 MenuItem 会更简单:

And MenuItem in XAML will be simplier:

<MenuItem Header="Edit" CommandParameter="{Binding}"
              Command="{Binding ParentViewModel.DataGridActionCommand}" />