Xceed DataGrid for WPF v7.2 Documentation
QueryItemsEventArgs Class
Members 


Xceed.Wpf.DataGrid Assembly > Xceed.Wpf.DataGrid Namespace : QueryItemsEventArgs Class
Provides information on the DataGridVirtualizingCollectionView to which the grid is bound including the items that have been fetched from the underlying data source.
Syntax
'Declaration
 
Public Class QueryItemsEventArgs 
   Inherits AsyncQueryEventArgs
'Usage
 
Dim instance As QueryItemsEventArgs
public class QueryItemsEventArgs : AsyncQueryEventArgs 
Remarks

The QueryItems event, which is raised whenever new records are required, allows the next batch of records to be fetched from the data source and provided to the grid. New items are provided to the grid by calling the EndQuery method, which is exposed by the AsyncQueryInfo instance received in the event arguments of the QueryItems event, with an array of items. The StartIndex property of the AsyncQueryInfo indicates the index in the data source at which to start retrieving the new items while its RequestedItemCount property represents the number of new items that should be returned. The current state of the collection view (e.g., sorting and filtering) must always be taken into consideration when returning new items. If the EndQuerymethod is called with an array that does not match the requested item count, the collection view will automatically refresh. If the array contains a null(Nothing in Visual Basic) value, an exception will be thrown.

The EndQuery method is considered thread-safe and can therefore be called from another thread in order to leave the main UI thread responsive when retrieving new items.

Inheritance Hierarchy

System.Object
   System.EventArgs
      Xceed.Wpf.DataGrid.AsyncQueryEventArgs
         Xceed.Wpf.DataGrid.QueryItemsEventArgs

Requirements

Target Platforms: Windows 11, Windows 10, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also

Reference

QueryItemsEventArgs Members
Xceed.Wpf.DataGrid Namespace