IBindingList Antarmuka
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Menyediakan fitur yang diperlukan untuk mendukung skenario kompleks dan sederhana saat mengikat ke sumber data.
public interface class IBindingList : System::Collections::IListpublic interface IBindingList : System.Collections.IListtype IBindingList = interface
interface ICollection
interface IEnumerable
interface IListtype IBindingList = interface
interface IList
interface ICollection
interface IEnumerablePublic Interface IBindingList
Implements IList- Turunan
- Penerapan
Contoh
Contoh berikut menyediakan implementasi sederhana antarmuka IBindingList . Kelas CustomerList menyimpan informasi pelanggan dalam daftar. Contoh ini mengasumsikan bahwa Anda telah menggunakan Customer kelas yang dapat ditemukan dalam contoh di IEditableObject kelas .
public ref class CustomersList: public CollectionBase, public IBindingList
{
private:
ListChangedEventArgs^ resetEvent;
ListChangedEventHandler^ onListChanged;
virtual event ListChangedEventHandler^ ListChanged;
public:
property bool AllowEdit
{
// Implements IBindingList.
virtual bool get() sealed
{
return true;
}
}
virtual property bool AllowNew
{
bool get()
{
return true;
}
}
property bool AllowRemove
{
virtual bool get()
{
return true;
}
}
property bool SupportsChangeNotification
{
virtual bool get()
{
return true;
}
}
property bool SupportsSearching
{
virtual bool get()
{
return true;
}
}
property bool SupportsSorting
{
virtual bool get()
{
return true;
}
}
// Methods.
virtual Object^ AddNew()
{
Customer^ c = gcnew Customer( this->Count->ToString() );
List->Add( c );
return c;
}
property bool IsSorted
{
// Unsupported properties.
virtual bool get()
{
throw gcnew NotSupportedException;
return false;
}
}
property ListSortDirection SortDirection
{
virtual ListSortDirection get()
{
throw gcnew NotSupportedException;
return ListSortDirection::Ascending;
}
}
property PropertyDescriptor^ SortProperty
{
virtual PropertyDescriptor^ get()
{
throw gcnew NotSupportedException;
return nullptr;
}
}
// Unsupported Methods.
virtual void AddIndex( PropertyDescriptor^ property )
{
throw gcnew NotSupportedException;
}
virtual void ApplySort( PropertyDescriptor^ property, ListSortDirection direction )
{
throw gcnew NotSupportedException;
}
virtual int Find( PropertyDescriptor^ property, Object^ key )
{
throw gcnew NotSupportedException;
return 0;
}
virtual void RemoveIndex( PropertyDescriptor^ property )
{
throw gcnew NotSupportedException;
}
virtual void RemoveSort()
{
throw gcnew NotSupportedException;
}
// Worker functions to populate the list with data.
static Customer^ ReadCustomer1()
{
Customer^ cust = gcnew Customer( "536-45-1245" );
cust->FirstName = "Jo";
cust->LastName = "Brown";
return cust;
}
static Customer^ ReadCustomer2()
{
Customer^ cust = gcnew Customer( "246-12-5645" );
cust->FirstName = "Robert";
cust->LastName = "Brown";
return cust;
}
protected:
virtual void OnListChanged( ListChangedEventArgs^ ev )
{
if ( onListChanged != nullptr )
{
onListChanged( this, ev );
}
}
virtual void OnClear() override
{
List->Clear();
}
virtual void OnClearComplete() override
{
OnListChanged( resetEvent );
}
virtual void OnInsertComplete( int index, Object^ value ) override
{
Customer^ c = safe_cast<Customer^>(value);
c->Parent = this;
OnListChanged( gcnew ListChangedEventArgs( ListChangedType::ItemAdded,index ) );
}
virtual void OnRemoveComplete( int index, Object^ value ) override
{
Customer^ c = safe_cast<Customer^>(value);
c->Parent = this;
OnListChanged( gcnew ListChangedEventArgs( ListChangedType::ItemDeleted,index ) );
}
virtual void OnSetComplete( int index, Object^ oldValue, Object^ newValue ) override
{
if ( oldValue != newValue )
{
Customer^ oldcust = safe_cast<Customer^>(oldValue);
Customer^ newcust = safe_cast<Customer^>(newValue);
oldcust->Parent = 0;
newcust->Parent = this;
OnListChanged( gcnew ListChangedEventArgs( ListChangedType::ItemAdded,index ) );
}
}
public:
// Constructor
CustomersList()
{
resetEvent = gcnew ListChangedEventArgs( ListChangedType::Reset,-1 );
}
void LoadCustomers()
{
IList^ l = static_cast<IList^>(this);
l->Add( ReadCustomer1() );
l->Add( ReadCustomer2() );
OnListChanged( resetEvent );
}
property Object^ Item [int]
{
Object^ get( int index )
{
return static_cast<Customer^>(List->Item[ index ]);
}
void set( int index, Object^ value )
{
List->Item[ index ] = value;
}
}
int Add( Customer^ value )
{
return List->Add( value );
}
Customer^ AddNew()
{
return safe_cast<Customer^>(static_cast<IBindingList^>(this)->AddNew());
}
void Remove( Customer^ value )
{
List->Remove( value );
}
internal:
// Called by Customer when it changes.
void CustomerChanged( Customer^ cust )
{
int index = List->IndexOf( cust );
OnListChanged( gcnew ListChangedEventArgs( ListChangedType::ItemChanged,index ) );
}
};
public class CustomersList : CollectionBase, IBindingList
{
private ListChangedEventArgs resetEvent = new ListChangedEventArgs(ListChangedType.Reset, -1);
private ListChangedEventHandler onListChanged;
public void LoadCustomers()
{
IList l = (IList)this;
l.Add(ReadCustomer1());
l.Add(ReadCustomer2());
OnListChanged(resetEvent);
}
public Customer this[int index]
{
get
{
return (Customer)(List[index]);
}
set
{
List[index] = value;
}
}
public int Add (Customer value)
{
return List.Add(value);
}
public Customer AddNew()
{
return (Customer)((IBindingList)this).AddNew();
}
public void Remove (Customer value)
{
List.Remove(value);
}
protected virtual void OnListChanged(ListChangedEventArgs ev)
{
if (onListChanged != null)
{
onListChanged(this, ev);
}
}
protected override void OnClear()
{
foreach (Customer c in List)
{
c.Parent = null;
}
}
protected override void OnClearComplete()
{
OnListChanged(resetEvent);
}
protected override void OnInsertComplete(int index, object value)
{
Customer c = (Customer)value;
c.Parent = this;
OnListChanged(new ListChangedEventArgs(ListChangedType.ItemAdded, index));
}
protected override void OnRemoveComplete(int index, object value)
{
Customer c = (Customer)value;
c.Parent = this;
OnListChanged(new ListChangedEventArgs(ListChangedType.ItemDeleted, index));
}
protected override void OnSetComplete(int index, object oldValue, object newValue)
{
if (oldValue != newValue)
{
Customer oldcust = (Customer)oldValue;
Customer newcust = (Customer)newValue;
oldcust.Parent = null;
newcust.Parent = this;
OnListChanged(new ListChangedEventArgs(ListChangedType.ItemAdded, index));
}
}
// Called by Customer when it changes.
internal void CustomerChanged(Customer cust)
{
int index = List.IndexOf(cust);
OnListChanged(new ListChangedEventArgs(ListChangedType.ItemChanged, index));
}
// Implements IBindingList.
bool IBindingList.AllowEdit
{
get { return true ; }
}
bool IBindingList.AllowNew
{
get { return true ; }
}
bool IBindingList.AllowRemove
{
get { return true ; }
}
bool IBindingList.SupportsChangeNotification
{
get { return true ; }
}
bool IBindingList.SupportsSearching
{
get { return false ; }
}
bool IBindingList.SupportsSorting
{
get { return false ; }
}
// Events.
public event ListChangedEventHandler ListChanged
{
add
{
onListChanged += value;
}
remove
{
onListChanged -= value;
}
}
// Methods.
object IBindingList.AddNew()
{
Customer c = new Customer(this.Count.ToString());
List.Add(c);
return c;
}
// Unsupported properties.
bool IBindingList.IsSorted
{
get { throw new NotSupportedException(); }
}
ListSortDirection IBindingList.SortDirection
{
get { throw new NotSupportedException(); }
}
PropertyDescriptor IBindingList.SortProperty
{
get { throw new NotSupportedException(); }
}
// Unsupported Methods.
void IBindingList.AddIndex(PropertyDescriptor property)
{
throw new NotSupportedException();
}
void IBindingList.ApplySort(PropertyDescriptor property, ListSortDirection direction)
{
throw new NotSupportedException();
}
int IBindingList.Find(PropertyDescriptor property, object key)
{
throw new NotSupportedException();
}
void IBindingList.RemoveIndex(PropertyDescriptor property)
{
throw new NotSupportedException();
}
void IBindingList.RemoveSort()
{
throw new NotSupportedException();
}
// Worker functions to populate the list with data.
private static Customer ReadCustomer1()
{
Customer cust = new Customer("536-45-1245");
cust.FirstName = "Jo";
cust.LastName = "Brown";
return cust;
}
private static Customer ReadCustomer2()
{
Customer cust = new Customer("246-12-5645");
cust.FirstName = "Robert";
cust.LastName = "Brown";
return cust;
}
}
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
Keterangan
Antarmuka ini diimplementasikan oleh DataView kelas . Implementasi metode harus menunjukkan perilaku yang sama dengan implementasi metode tersebut di DataView kelas .
Ketika Anda memanggil ApplySort metode atau RemoveSort , Anda harus menaikkan ListChanged peristiwa dengan Reset enumerasi.
Ketika Anda memanggil AddNew metode , Anda harus menaikkan ListChanged peristiwa dengan ItemAdded enumerasi yang membawa indeks yang sesuai. Baris yang ditambahkan berada dalam status di mana menekan ESC pada DataGridView kontrol dapat menghapus baris baru. Menaikkan ListChanged peristiwa dengan ItemAdded enumerasi untuk kedua kalinya pada baris ini menunjukkan bahwa item sekarang menjadi baris yang tidak dalam status "baru".
Saat Anda menghapus item atau memanggil CancelEdit metode pada baris baru (jika baris tersebut mengimplementasikan IEditableObject), Anda harus menaikkan ListChanged peristiwa dengan ItemDeleted enumerasi yang membawa indeks yang sesuai.
Properti
| AllowEdit |
Mendapatkan apakah Anda bisa memperbarui item dalam daftar. |
| AllowNew |
Mendapatkan apakah Anda dapat menambahkan item ke daftar menggunakan AddNew(). |
| AllowRemove |
Mendapatkan apakah Anda dapat menghapus item dari daftar, menggunakan Remove(Object) atau RemoveAt(Int32). |
| Count |
Mendapatkan jumlah elemen yang terkandung dalam ICollection. (Diperoleh dari ICollection) |
| IsFixedSize |
Mendapatkan nilai yang menunjukkan apakah IList memiliki ukuran tetap. (Diperoleh dari IList) |
| IsReadOnly |
Mendapatkan nilai yang menunjukkan apakah IList bersifat baca-saja. (Diperoleh dari IList) |
| IsSorted |
Mendapatkan apakah item dalam daftar diurutkan. |
| IsSynchronized |
Mendapatkan nilai yang menunjukkan apakah akses ke disinkronkan ICollection (utas aman). (Diperoleh dari ICollection) |
| Item[Int32] |
Mendapatkan atau mengatur elemen pada indeks yang ditentukan. (Diperoleh dari IList) |
| SortDirection |
Mendapatkan arah semacam itu. |
| SortProperty |
PropertyDescriptor Mendapatkan yang sedang digunakan untuk pengurutan. |
| SupportsChangeNotification |
Mendapatkan apakah ListChanged peristiwa dimunculkan saat daftar berubah atau item dalam daftar berubah. |
| SupportsSearching |
Mendapatkan apakah daftar mendukung pencarian menggunakan Find(PropertyDescriptor, Object) metode . |
| SupportsSorting |
Mendapatkan apakah daftar mendukung pengurutan. |
| SyncRoot |
Mendapatkan objek yang dapat digunakan untuk menyinkronkan akses ke ICollection. (Diperoleh dari ICollection) |
Metode
| Add(Object) |
Menambahkan item ke IList. (Diperoleh dari IList) |
| AddIndex(PropertyDescriptor) |
Menambahkan ke PropertyDescriptor indeks yang digunakan untuk pencarian. |
| AddNew() |
Menambahkan item baru ke daftar. |
| ApplySort(PropertyDescriptor, ListSortDirection) |
Mengurutkan daftar berdasarkan PropertyDescriptor dan ListSortDirection. |
| Clear() |
Menghapus semua item dari IList. (Diperoleh dari IList) |
| Contains(Object) |
Menentukan apakah IList berisi nilai tertentu. (Diperoleh dari IList) |
| CopyTo(Array, Int32) |
Menyalin elemen ICollection ke Array, dimulai dari indeks tertentu Array . (Diperoleh dari ICollection) |
| Find(PropertyDescriptor, Object) |
Mengembalikan indeks baris yang memiliki .PropertyDescriptor |
| GetEnumerator() |
Mengembalikan enumerator yang berulang melalui koleksi. (Diperoleh dari IEnumerable) |
| IndexOf(Object) |
Menentukan indeks item tertentu di IList. (Diperoleh dari IList) |
| Insert(Int32, Object) |
Sisipkan item ke pada IList indeks yang ditentukan. (Diperoleh dari IList) |
| Remove(Object) |
Menghapus kemunculan pertama objek tertentu dari IList. (Diperoleh dari IList) |
| RemoveAt(Int32) |
IList Menghapus item pada indeks yang ditentukan. (Diperoleh dari IList) |
| RemoveIndex(PropertyDescriptor) |
PropertyDescriptor Menghapus dari indeks yang digunakan untuk pencarian. |
| RemoveSort() |
Menghapus pengurutan apa pun yang diterapkan menggunakan ApplySort(PropertyDescriptor, ListSortDirection). |
Acara
| ListChanged |
Terjadi ketika daftar berubah atau item dalam daftar berubah. |
Metode Ekstensi
| Cast<TResult>(IEnumerable) |
Mentransmisikan elemen dari ke IEnumerable jenis yang ditentukan. |
| OfType<TResult>(IEnumerable) |
Memfilter elemen berdasarkan IEnumerable jenis yang ditentukan. |
| AsParallel(IEnumerable) |
Mengaktifkan paralelisasi kueri. |
| AsQueryable(IEnumerable) |
Mengonversi menjadi IEnumerableIQueryable. |
