c# - 从两个不同的 View 绑定(bind)到数据源。 MVVM、WPF

Question

所以这里是设置。我有两个不同的 WPF View 。 StandardEngineeredView 和 StandardEngineeredPrintView。我的 StandardEngineeredViewModel 中有一个名为 ModelRevisionList 的 ObservableCollection。

我正在做的是尝试从两个不同的 View 绑定(bind)到 ModelRevisionList 数据源。我将 View 的数据上下文设置为相同的 View 模型。我的 StandardEngineeredView 中有一个按钮可将我导航到 StandardEngineeredPrintView。第二个 View 本质上只是用于允许某人打印数据。请注意，我将在两个 View 的 View 模型中绑定(bind)到其他几个属性。我只是还没有尝试这样做，因为在尝试绑定(bind)到修订列表时，我收到以下错误:

System.Windows.Markup.XamlParseException HResult=0x80131501 Message='Add value to collection of type 'System.Windows.Controls.ItemCollection' threw an exception.' Line number '204' and line position '55'. Source=PresentationFramework StackTrace: at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri) at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri) at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream) at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator) at LabelPrinting.Views.EngineeringViews.StandardEngineeredPrintView.InitializeComponent() in C:\Users\eric_obermuller\source\repos\LabelPrinting\LabelPrinting\Views\EngineeringViews\StandardEngineeredPrintView.xaml:line 1

Inner Exception 1: InvalidOperationException: Operation is not valid while ItemsSource is in use. Access and modify elements with ItemsControl.ItemsSource instead.

相关信息

我正在使用 MVVM Light。

我的第一个 View 最初绑定(bind)到可观察集合，并且数据在 View 中显示得很好。

两个 View 使用相同的数据上下文。

当我从 View 模型中获取可观察集合时，会引发错误。

StandardEngineeredViewModel 修订列表

private ObservableCollection<Revision> _ModelRevisionList = new ObservableCollection<Revision>();
public ObservableCollection<Revision> ModelRevisionList
{
    get { return _ModelRevisionList; } //Error thrown here upon get
    set { Set(ref _ModelRevisionList, value); }
}

绑定(bind)的StandarEngineeredView列表框

<ListBox
   BorderBrush="{StaticResource BackgroundBlueBrush}" 
   ItemsSource="{Binding ModelRevisionList}" 
   SelectedItem="{Binding SelectedRevision}"
   DisplayMemberPath="Date" 
   Margin="70 10" 
   MinHeight="150"
   MaxHeight="150"
   ItemStringFormat="{}{0:MM/dd/yyyy}"/>

StandardEngineeredPrintView 绑定(bind)的gridview

<Border Grid.Column="1" MaxHeight="250" MaxWidth="400" MinWidth="400">
    <DataGrid ItemsSource="{Binding ModelRevisionList}" AutoGenerateColumns="False">
        <DataGridTextColumn Header="Date" Binding="{Binding Date}"/>
        <DataGridTextColumn Header="Edited By" Binding="{Binding EditedBy}"/>
        <DataGridTextColumn Header="Description" Binding="{Binding Description}"/>
    </DataGrid>
</Border>

在两个 View 中设置的数据上下文

DataContext="{Binding StandardEngineeredViewInstance, Source={StaticResource Locator}}"

查看模型定位器

 public class ViewModelLocator
{
    /// <summary>
    /// Initializes a new instance of the ViewModelLocator class.
    /// </summary>
    public ViewModelLocator()
    {
        ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default);
        SetupNavigation();

        if (ViewModelBase.IsInDesignModeStatic)
        {
            // Create design time view services and models
            SimpleIoc.Default.Register<IDataAccessService, DataAccessService>();
        }
        else
        {
            // Create run time view services and models

            SimpleIoc.Default.Register<IDataAccessService, DataAccessService>();
        }
    }

    public StandardEngineeredViewModel StandardEngineeredViewInstance
    {
        get
        {
            SimpleIoc.Default.Register<StandardEngineeredViewModel>();
            return ServiceLocator.Current.GetInstance<StandardEngineeredViewModel>();
        }
    }

    public static void Cleanup()
    {
        // TODO Clear the ViewModels
    }
    private static void SetupNavigation()
    {
        SimpleIoc.Default.Unregister<IFrameNavigationService>();
        var navigationService = new FrameNavigationService();
        navigationService.Configure("StandardEngineeredPrintView", new Uri("/Views/EngineeringViews/StandardEngineeredPrintView.xaml", UriKind.Relative));
        SimpleIoc.Default.Register<IFrameNavigationService>(() => navigationService);
    }
}

现在由于错误，我认为这与我在导航到 StandardEngineeredPrintView 之前在我的 StandardEngineeredView 中使用可观察集合的事实有关。您能否将两个 View 绑定(bind)到同一个数据源？我做错了什么我只是不知道吗？

我很感激任何建议，如果您想了解更多信息/代码，请说出来。

谢谢!

Answer 1

好的，解决方案非常简单。我的数据网格设置不正确。我不得不将其更改为:

<DataGrid ItemsSource="{Binding ModelRevisionList}" AutoGenerateColumns="False">
     <DataGrid.Columns>
          <DataGridTextColumn Header="Date" Binding="{Binding Date}"/>
          <DataGridTextColumn Header="Edited By" Binding="{Binding EditedBy}"/>
          <DataGridTextColumn Header="Description" Binding="{Binding Description}"/>
     </DataGrid.Columns>
</DataGrid>

忘记了 DataGrid.Columns