自动展开RadGridView新增行的RowDetails

本文关键字：新增行 RowDetails RadGridView | 更新日期: 2023-09-27 17:51:02

我想解决的问题:当向RadGridView添加新项时，将相应地创建新行。我希望这些新行自动扩展RowDetails。

我试过了:我尝试从代码后端访问RadGridView，并注册一个监听新项目的事件处理程序。它会将新条目标记为selected，从而展开RowDetails (RowDetailsVisibilityMode是VisibleWhenSelected)。

我所面临的问题:RadGridView位于另一个控件资源的数据模板中。如果我为数据模板设置了显式的x:Key，我可以通过代码访问数据模板;但是，如果仅为数据模板设置DataType，则资源中的每个字典条目都具有空值。

问题是，如果我确实为数据模板设置了显式的x:Key，我就不能再让我的控件根据数据类型动态决定使用哪个数据模板(没有选择数据模板，我只看到一个大空白)。我如何获得数据模板内的控件?

下面是我的代码:

XAML: 

<telerik:RadTabControl x:Name="radTabControl">
    <telerik:RadTabControl.Resources>
        <DataTemplate x:Key="TabControlTemplate">
            <ContentControl Content="{Binding}">
                <ContentControl.Resources>
                    <!-- Wrapper1 (inherits from Wrapper) -->
                    <DataTemplate DataType="local:Wrapper1Collection">
                        <telerik:RadGridView ItemsSource="{Binding}">
                        ....
                        </telerik:RadGridView>
                    </DataTemplate>
                    <!-- Wrapper2 (inherits from Wrapper) -->
                    <DataTemplate DataType="local:Wrapper2Collection">
                        <telerik:RadGridView ItemsSource="{Binding}">
                        ....
                        </telerik:RadGridView>
                    </DataTemplate>
                    <!-- Fallback to displaying nothing for unknown wrapper types -->
                    <DataTemplate DataType="local:WrapperCollection" />
                </ContentControl.Resources>
            </ContentControl>
        </DataTemplate>
    </telerik:RadTabControl.Resources>
    <telerik:RadTabItem Content="{Binding Path=Wrappers}"
                        ContentTemplate="{StaticResource TabControlTemplate}" />
    <telerik:RadTabItem Content="{Binding Path=Wrappers}"
                        ContentTemplate="{StaticResource TabControlTemplate}" />
</telerik:RadTabControl>
c#后台代码:

public ContentUpdateView()
{
    InitializeComponent();
    DataTemplate tabControlTemplate =
        (DataTemplate)(radTabControl.Resources["TabControlTemplate"]);
    FrameworkElement radGridViewContentControl =
        (FrameworkElement)(tabControlTemplate.LoadContent());
    foreach (DictionaryEntry resourceEntry in radGridViewContentControl.Resources)
    {
        if (resourceEntry.Value != null)
        {
            DataTemplate radGridViewDataTemplate = (DataTemplate)(resourceEntry.Value);
            RadGridView radGridView = (RadGridView)(radGridViewDataTemplate.LoadContent());
            radGridView.Items.CollectionChanged += (s, e) =>
            {
                if (e.Action == NotifyCollectionChangedAction.Add)
                {
                    foreach (Wrapper wrapper in e.NewItems)
                    {
                        radGridView.SelectedItems.Add(wrapper);
                    }
                }
            };
        }
    }
}

请注意，Wrapper类是Wrapper1和Wrapper2继承的抽象类，并且我的视图模型上的Wrappers路径是WrapperCollection，这是一个继承自ObservableCollection<Wrapper>的抽象类，Wrapper1Collection和Wrapper2Collection继承自。

自动展开RadGridView新增行的RowDetails

好吧，根据你的评论，我不会回答"如何访问[…][…]?"，但试图给出一个答案，"如何自动展开RowDetails的新添加行的RadGridView?"。

我推荐为您的RadGridView定制Behavior，它侦听新添加的行并执行RowDetail扩展。

<RadGridView>
    <Interaction.Behaviors>
        <ExpandDetailsOfNewRowsBehavior/>
    </Interaction.Behaviors>
</RadGridView>

和代码:

public class ExpandDetailsOfNewRowsBehavior : Behavior<RadGridView>
{
    protected override void OnAttached()
    {
        base.OnAttached();
        INotifyCollectionChanged items = AssociatedObject.Items;
        items.CollectionChanged += OnItemsChanged;
        AssociatedObject.RowLoaded += CheckLoadedRowIfShouldExpand;
    }
    private void CheckLoadedRowIfShouldExpand()
    {
        var iterationCopy = m_shouldBeExpanded.ToArray();
        foreach(var item in iterationCopy)
        {
            GridViewRow row = AssociatedObject.GetRowForItem( item );
            if ( row != null )
            {
                row.DetailsVisibility = Visibility.Visible;
                m_shouldBeExpanded.Remove(item);
            }
        }
    }
    private List<object> m_shouldBeExpanded = new List<object>();
    private void OnItemsChanged(object sender, NotifyCollectionChangedEventArgs eventArgs)
    {
        if (eventArgs.Action == NotifyCollectionChangedAction.Add)
        {
            foreach (var item in eventArgs.NewItems)
            {
              GridViewRow row = AssociatedObject.GetRowForItem( item );
              if ( row == null )
              {
                // row is not loaded yet
                m_shouldBeExpanded.Add(item);
              }
              else
              {
                row.DetailsVisibility = Visibility.Visible;
                // see http://docs.telerik.com/devtools/silverlight/
                //                  controls/radgridview/row-details/programming
                // "To manually change the visibility of a row - set its
                // DetailsVisibility property to either Visibility.Collapsed
                // or Visibility.Visible"
              }
            }
        }
    }
    protected override void OnDetaching()
    {
        INotifyCollectionChanged items = AssociatedObject.Items;
        items.CollectionChanged -= OnItemsChanged;
        AssociatedObject.RowLoaded -= CheckLoadedRowIfShouldExpand;
        base.OnDetaching();
    }
}

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