c# - WPF 数据网格 : Save cell changes immediately with MVVM

Question

我有一个简化的 DataGrid，如下所示:

<DataGrid AutoGenerateColumns="False" 
          ItemsSource="{Binding Parts}" 
          SelectedItem="{Binding SelectedPart}" >
    <DataGrid.Columns>
        <DataGridTextColumn Header="Name" Binding="{Binding Path=Name, Mode=TwoWay}" />
        <DataGridTemplateColumn Header="PartType" >
            <DataGridTemplateColumn.CellEditingTemplate>
                <DataTemplate>
                    <ComboBox ItemsSource="{Binding RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}, Path=DataContext.PartTypes}" 
                              SelectedItem="{Binding PartType, Mode=TwoWay, UpdateSourceTrigger=LostFocus}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellEditingTemplate>
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding PartType}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

我的 ViewModel 看起来像这样:

public class PartListViewModel
{
    private ObservableCollection<Part> _parts;
    public ObservableCollection<Part> Parts
    {
        get { return _parts; }
        set
        {
            _parts = value;
             OnPropertyChanged("Parts");
        }
    }

    private Part _selectedPart;
    public Part SelectedPart
    {
        get { return _selectedPart; }
        set
        {
            _selectedPart = value;
            OnPropertyChanged("SelectedPart");
        }
    }
}

现在我希望对数据网格单元格的更改立即存储到数据库中。如何在 MVVM 中做到这一点？

目前，我监听 DataGrid 的 OnCellEditEnding 事件并将记录保存在代码隐藏中。但这非常难看:

private void DataGrid_OnCellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
{
    var viewModel = (PartListViewModel) DataContext;
    viewModel.SavePart((Part) e.Row.Item);
}

Answer 1

你可以做这样的事情。(您需要添加对 System.Windows.Interactivity 的引用， you can download the assemblies from here )

然后在 XAML 中添加对命名空间的引用。xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"

<i:Interaction.Triggers>
  <i:EventTrigger EventName="CellEditEnding">
     <i:InvokeCommandAction Command="{Binding SomeCommand}"/>
  </i:EventTrigger>
</i:Interaction.Triggers>