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CollectionView.IsCurrentBeforeFirst Property

Gets a value that indicates whether the CurrentItem of the view is before the beginning of the collection.

Namespace:  System.Windows.Data
Assembly:  PresentationFramework (in PresentationFramework.dll)

public virtual bool IsCurrentBeforeFirst { get; }
You cannot set this property in XAML.

Property Value

Type: System.Boolean
true if the CurrentItem of the view is before the beginning of the collection; otherwise, false.

Implements

ICollectionView.IsCurrentBeforeFirst

Collection views support the concept of a current record pointer. As you navigate through the objects in a collection view, you are moving a record pointer that allows you to retrieve the object that exists at that particular location in the collection.

Views allow the same data collection to be viewed in different ways, depending on sorting, filtering, or grouping. Views also provide a current record pointer concept and enable moving the pointer. This example shows how to get the current object as well as navigate through the objects in a data collection using the functionality provided in the CollectionView class.

In this example, myCollectionView is a CollectionView object that is a view over a bound collection.

In the following example, OnButton is an event handler for the Previous and Next buttons in an application, which are buttons that allow the user to navigate the data collection. Note that the IsCurrentBeforeFirst and IsCurrentAfterLast properties report whether the current record pointer has come to the beginning and the end of the list respectively so that MoveCurrentToFirst and MoveCurrentToLast can be called as appropriately.

The CurrentItem property of the view is cast as an Order to return the current order item in the collection.

//OnButton is called whenever the Next or Previous buttons 
//are clicked to change the currency 
  private void OnButton(Object sender, RoutedEventArgs args)
  {
      Button b = sender as Button;

      switch (b.Name)
      {
          case "Previous":
              myCollectionView.MoveCurrentToPrevious();

              if (myCollectionView.IsCurrentBeforeFirst)
              {
                  myCollectionView.MoveCurrentToLast();
              }
              break;

          case "Next":
              myCollectionView.MoveCurrentToNext();
              if (myCollectionView.IsCurrentAfterLast)
              {
                  myCollectionView.MoveCurrentToFirst();
              }
              break;

          o = myCollectionView.CurrentItem as Order;
          // TODO: do something with the current Order o 
      }
  }

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0

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