IBindingList Interface

 

Provides the features required to support both complex and simple scenarios when binding to a data source.

Namespace:   System.ComponentModel
Assembly:  System (in System.dll)

Public Interface IBindingList
	Inherits IList, ICollection, IEnumerable

NameDescription
System_CAPS_pubpropertyAllowEdit

Gets whether you can update items in the list.

System_CAPS_pubpropertyAllowNew

Gets whether you can add items to the list using AddNew.

System_CAPS_pubpropertyAllowRemove

Gets whether you can remove items from the list, using Remove or RemoveAt.

System_CAPS_pubpropertyCount

Gets the number of elements contained in the ICollection.(Inherited from ICollection.)

System_CAPS_pubpropertyIsFixedSize

Gets a value indicating whether the IList has a fixed size.(Inherited from IList.)

System_CAPS_pubpropertyIsReadOnly

Gets a value indicating whether the IList is read-only.(Inherited from IList.)

System_CAPS_pubpropertyIsSorted

Gets whether the items in the list are sorted.

System_CAPS_pubpropertyIsSynchronized

Gets a value indicating whether access to the ICollection is synchronized (thread safe).(Inherited from ICollection.)

System_CAPS_pubpropertyItem(Int32)

Gets or sets the element at the specified index.(Inherited from IList.)

System_CAPS_pubpropertySortDirection

Gets the direction of the sort.

System_CAPS_pubpropertySortProperty

Gets the PropertyDescriptor that is being used for sorting.

System_CAPS_pubpropertySupportsChangeNotification

Gets whether a ListChanged event is raised when the list changes or an item in the list changes.

System_CAPS_pubpropertySupportsSearching

Gets whether the list supports searching using the Find method.

System_CAPS_pubpropertySupportsSorting

Gets whether the list supports sorting.

System_CAPS_pubpropertySyncRoot

Gets an object that can be used to synchronize access to the ICollection.(Inherited from ICollection.)

NameDescription
System_CAPS_pubmethodAdd(Object)

Adds an item to the IList.(Inherited from IList.)

System_CAPS_pubmethodAddIndex(PropertyDescriptor)

Adds the PropertyDescriptor to the indexes used for searching.

System_CAPS_pubmethodAddNew()

Adds a new item to the list.

System_CAPS_pubmethodApplySort(PropertyDescriptor, ListSortDirection)

Sorts the list based on a PropertyDescriptor and a ListSortDirection.

System_CAPS_pubmethodClear()

Removes all items from the IList.(Inherited from IList.)

System_CAPS_pubmethodContains(Object)

Determines whether the IList contains a specific value.(Inherited from IList.)

System_CAPS_pubmethodCopyTo(Array, Int32)

Copies the elements of the ICollection to an Array, starting at a particular Array index.(Inherited from ICollection.)

System_CAPS_pubmethodFind(PropertyDescriptor, Object)

Returns the index of the row that has the given PropertyDescriptor.

System_CAPS_pubmethodGetEnumerator()

Returns an enumerator that iterates through a collection.(Inherited from IEnumerable.)

System_CAPS_pubmethodIndexOf(Object)

Determines the index of a specific item in the IList.(Inherited from IList.)

System_CAPS_pubmethodInsert(Int32, Object)

Inserts an item to the IList at the specified index.(Inherited from IList.)

System_CAPS_pubmethodRemove(Object)

Removes the first occurrence of a specific object from the IList.(Inherited from IList.)

System_CAPS_pubmethodRemoveAt(Int32)

Removes the IList item at the specified index.(Inherited from IList.)

System_CAPS_pubmethodRemoveIndex(PropertyDescriptor)

Removes the PropertyDescriptor from the indexes used for searching.

System_CAPS_pubmethodRemoveSort()

Removes any sort applied using ApplySort.

NameDescription
System_CAPS_pubeventListChanged

Occurs when the list changes or an item in the list changes.

NameDescription
System_CAPS_pubmethodAsParallel()

Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)

System_CAPS_pubmethodAsQueryable()

Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)

System_CAPS_pubmethodCast(Of TResult)()

Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)

System_CAPS_pubmethodOfType(Of TResult)()

Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

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

.NET Framework
Available since 1.1
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