共用方式為


CurrentChangingEventArgs 類別

定義

提供 CurrentChanging 事件的資料。

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class CurrentChangingEventArgs
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public class CurrentChangingEventArgs
Public Class CurrentChangingEventArgs
繼承
Object IInspectable CurrentChangingEventArgs
屬性

Windows 需求

裝置系列
Windows 10 (已於 10.0.10240.0 引進)
API contract
Windows.Foundation.UniversalApiContract (已於 v1.0 引進)

範例

下列程式碼範例示範如何處理 CurrentChanging 事件。 在此範例中,XAML 會顯示系結至CollectionViewSourceGridView頁面內容。 程式碼後置會顯示 CollectionViewSource 初始化,其中包括設定其 Source 並擷取其 View ,以附加 CurrentChanging 事件處理常式。

<Page.Resources>
  <CollectionViewSource x:Name="cvs" />
  <DataTemplate x:Key="myDataTemplate">
    <Border Background="#FF939598" Width="200" Height="200">
      <TextBlock Text="{Binding Path=Name}" />
    </Border>
  </DataTemplate>
</Page.Resources>

<Grid Background="{StaticResource ApplicationPageBackgroundBrush}">
  <GridView x:Name="PicturesGrid" 
    SelectionMode="Single" CanReorderItems="False" CanDragItems="False"
    ItemsSource="{Binding Source={StaticResource cvs}}"                
    ItemTemplate="{StaticResource myDataTemplate}" >
    <GridView.ItemsPanel>
      <ItemsPanelTemplate>
        <WrapGrid VerticalChildrenAlignment="Top" 
          HorizontalChildrenAlignment="Left" />
      </ItemsPanelTemplate>
    </GridView.ItemsPanel>
  </GridView>
</Grid>
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    var library = Windows.Storage.KnownFolders.PicturesLibrary;
    var queryOptions = new Windows.Storage.Search.QueryOptions();
    queryOptions.FolderDepth = Windows.Storage.Search.FolderDepth.Deep;
    queryOptions.IndexerOption = 
        Windows.Storage.Search.IndexerOption.UseIndexerWhenAvailable;

    var fileQuery = library.CreateFileQueryWithOptions(queryOptions);

    var fif = new Windows.Storage.BulkAccess.FileInformationFactory(
        fileQuery, 
        Windows.Storage.FileProperties.ThumbnailMode.PicturesView, 190, 
        Windows.Storage.FileProperties.ThumbnailOptions.UseCurrentScale, 
        false);

    var dataSource = fif.GetVirtualizedFilesVector();
    cvs.Source = dataSource;
    cvs.View.CurrentChanging += View_CurrentChanging;
}

private void View_CurrentChanging(object sender, CurrentChangingEventArgs e)
{
    Debug.WriteLine("Cancel = " + e.Cancel);
    Debug.WriteLine("IsCancelable = " + e.IsCancelable);
    if (e.IsCancelable == true)
    {
        // Cancel the change. The previously selected item remains selected.
        e.Cancel = true;
    }
}

備註

CurrentChanging事件發生于ICollectionView實作中的CurrentItem屬性值變更時。 ICollectionView 實作會使用 CurrentChangingEventArgs 建構函式來指定您是否可以在CurrentChanging事件處理常式中取消CurrentItem變更。 如果IsCancelable屬性值為true,您可以將Cancel屬性設定為true來取消CurrentItem變更。 否則,您無法取消 CurrentItem 變更。

建構函式

CurrentChangingEventArgs()

初始化 CurrentChangingEventArgs 類別的新實例。

CurrentChangingEventArgs(Boolean)

初始化 CurrentChangingEventArgs 類別的新實例。

屬性

Cancel

取得或設定值,這個值表示是否應該取消 CurrentItem 變更。

IsCancelable

取得值,這個值表示是否可以取消 CurrentItem 變更。

適用於

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