IBindingList Interface
Provides the features required to support both complex and simple scenarios when binding to a data source.
Assembly: System (in System.dll)
This interface is implemented by the DataView class. Implementation of a method should exhibit the same behavior as the implementation of that method in the DataView class.
When you call the ApplySort or RemoveSort methods, you should raise a ListChanged event with the Reset enumeration.
When you call the AddNew method, you should raise a ListChanged event with the ItemAdded enumeration carrying the appropriate index. The added row is in a state where pressing the ESC on a DataGridView control can remove the new row. Raising the ListChanged event with the ItemAdded enumeration a second time on this row indicates that the item is now a row not in the "new" state.
When you remove an item or call the CancelEdit method on a new row (if that row implements IEditableObject), you should raise a ListChanged event with the ItemDeleted enumeration carrying the appropriate index.
The following example provides a simple implementation of the IBindingList interface. The CustomerList class stores customer information in a list. This example assumes that you have used the Customer class that can be found in the example in the IEditableObject class.
Public Class CustomersList Inherits CollectionBase Implements IBindingList Private resetEvent As New ListChangedEventArgs(ListChangedType.Reset, -1) Private onListChanged1 As ListChangedEventHandler Public Sub LoadCustomers() Dim l As IList = CType(Me, IList) l.Add(ReadCustomer1()) l.Add(ReadCustomer2()) OnListChanged(resetEvent) End Sub Default Public Property Item(ByVal index As Integer) As Customer Get Return CType(List(index), Customer) End Get Set(ByVal Value As Customer) List(index) = Value End Set End Property Public Function Add(ByVal value As Customer) As Integer Return List.Add(value) End Function Public Function AddNew2() As Customer Return CType(CType(Me, IBindingList).AddNew(), Customer) End Function Public Sub Remove(ByVal value As Customer) List.Remove(value) End Sub Protected Overridable Sub OnListChanged(ByVal ev As ListChangedEventArgs) If (onListChanged1 IsNot Nothing) Then onListChanged1(Me, ev) End If End Sub Protected Overrides Sub OnClear() Dim c As Customer For Each c In List c.parent = Nothing Next c End Sub Protected Overrides Sub OnClearComplete() OnListChanged(resetEvent) End Sub Protected Overrides Sub OnInsertComplete(ByVal index As Integer, ByVal value As Object) Dim c As Customer = CType(value, Customer) c.parent = Me OnListChanged(New ListChangedEventArgs(ListChangedType.ItemAdded, index)) End Sub Protected Overrides Sub OnRemoveComplete(ByVal index As Integer, ByVal value As Object) Dim c As Customer = CType(value, Customer) c.parent = Me OnListChanged(New ListChangedEventArgs(ListChangedType.ItemDeleted, index)) End Sub Protected Overrides Sub OnSetComplete(ByVal index As Integer, ByVal oldValue As Object, ByVal newValue As Object) If oldValue <> newValue Then Dim oldcust As Customer = CType(oldValue, Customer) Dim newcust As Customer = CType(newValue, Customer) oldcust.parent = Nothing newcust.parent = Me OnListChanged(New ListChangedEventArgs(ListChangedType.ItemAdded, index)) End If End Sub ' Called by Customer when it changes. Friend Sub CustomerChanged(ByVal cust As Customer) Dim index As Integer = List.IndexOf(cust) OnListChanged(New ListChangedEventArgs(ListChangedType.ItemChanged, index)) End Sub ' Implements IBindingList. ReadOnly Property AllowEdit() As Boolean Implements IBindingList.AllowEdit Get Return True End Get End Property ReadOnly Property AllowNew() As Boolean Implements IBindingList.AllowNew Get Return True End Get End Property ReadOnly Property AllowRemove() As Boolean Implements IBindingList.AllowRemove Get Return True End Get End Property ReadOnly Property SupportsChangeNotification() As Boolean Implements IBindingList.SupportsChangeNotification Get Return True End Get End Property ReadOnly Property SupportsSearching() As Boolean Implements IBindingList.SupportsSearching Get Return False End Get End Property ReadOnly Property SupportsSorting() As Boolean Implements IBindingList.SupportsSorting Get Return False End Get End Property ' Events. Public Event ListChanged As ListChangedEventHandler Implements IBindingList.ListChanged ' Methods. Function AddNew() As Object Implements IBindingList.AddNew Dim c As New Customer(Me.Count.ToString()) List.Add(c) Return c End Function ' Unsupported properties. ReadOnly Property IsSorted() As Boolean Implements IBindingList.IsSorted Get Throw New NotSupportedException() End Get End Property ReadOnly Property SortDirection() As ListSortDirection Implements IBindingList.SortDirection Get Throw New NotSupportedException() End Get End Property ReadOnly Property SortProperty() As PropertyDescriptor Implements IBindingList.SortProperty Get Throw New NotSupportedException() End Get End Property ' Unsupported Methods. Sub AddIndex(ByVal prop As PropertyDescriptor) Implements IBindingList.AddIndex Throw New NotSupportedException() End Sub Sub ApplySort(ByVal prop As PropertyDescriptor, ByVal direction As ListSortDirection) Implements IBindingList.ApplySort Throw New NotSupportedException() End Sub Function Find(ByVal prop As PropertyDescriptor, ByVal key As Object) As Integer Implements IBindingList.Find Throw New NotSupportedException() End Function Sub RemoveIndex(ByVal prop As PropertyDescriptor) Implements IBindingList.RemoveIndex Throw New NotSupportedException() End Sub Sub RemoveSort() Implements IBindingList.RemoveSort Throw New NotSupportedException() End Sub ' Worker functions to populate the list with data. Private Shared Function ReadCustomer1() As Customer Dim cust As New Customer("536-45-1245") cust.FirstName = "Jo" cust.LastName = "Brown" Return cust End Function Private Shared Function ReadCustomer2() As Customer Dim cust As New Customer("246-12-5645") cust.FirstName = "Robert" cust.LastName = "Brown" Return cust End Function End Class
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
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.