IBindingList 介面
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
提供繫結至資料來源時支援複雜和簡單案例所需的功能。
public interface class IBindingList : System::Collections::IList
public interface IBindingList : System.Collections.IList
type IBindingList = interface
interface ICollection
interface IEnumerable
interface IList
type IBindingList = interface
interface IList
interface ICollection
interface IEnumerable
Public Interface IBindingList
Implements IList
- 衍生
- 實作
範例
下列範例提供介面的 IBindingList 簡單實作。 類別會將 CustomerList
客戶資訊儲存在清單中。 此範例假設您已使用 Customer
類別中可在 類別的範例中找到的 IEditableObject 類別。
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
備註
這個介面是由類別實作 DataView 。 方法的實作應該與 類別中 DataView 該方法的實作相同行為。
當您呼叫 ApplySort 或 RemoveSort 方法時,應該使用 Reset 列舉引發ListChanged事件。
當您呼叫 AddNew 方法時,應該使用具有適當索引的ItemAdded列舉引發 ListChanged 事件。 新增的數據列處於按下控制件上的 DataGridView ESC 可移除新數據列的狀態。 ListChanged在這個數據列上,使用列舉引發事件ItemAdded,表示專案現在是不是處於「新」狀態的數據列。
當您移除專案或在新的數據列上呼叫 CancelEdit 方法 (時,如果該數據列實 IEditableObject 作) ,則應該引發 ListChanged 具有適當索引之 ItemDeleted 列舉的事件。
屬性
AllowEdit |
取得值,指出您是否可以更新清單中的項目。 |
AllowNew |
取得值,指出您是否可以使用 AddNew() 將項目加入清單。 |
AllowRemove |
取得值,指出您是否可以使用 Remove(Object) 或 RemoveAt(Int32) 從清單移除項目。 |
Count |
取得 ICollection 中所包含的項目數。 (繼承來源 ICollection) |
IsFixedSize |
取得值,指出 IList 是否有固定的大小。 (繼承來源 IList) |
IsReadOnly |
取得值,指出 IList 是否唯讀。 (繼承來源 IList) |
IsSorted |
取得值,指出清單中項目是否已排序。 |
IsSynchronized |
取得值,這個值表示對 ICollection 的存取是否同步 (安全執行緒)。 (繼承來源 ICollection) |
Item[Int32] |
在指定的索引位置上取得或設定項目。 (繼承來源 IList) |
SortDirection |
取得排序的方向。 |
SortProperty |
取得已經用來排序的 PropertyDescriptor。 |
SupportsChangeNotification |
取得值,指出當清單變更或清單項目變更時是否引發 ListChanged 事件。 |
SupportsSearching |
取得值,指出清單是否支援使用 Find(PropertyDescriptor, Object) 方法進行搜尋。 |
SupportsSorting |
取得值,指出清單是否支援排序。 |
SyncRoot |
取得可用以同步存取 ICollection 的物件。 (繼承來源 ICollection) |
方法
Add(Object) |
將項目加入至 IList。 (繼承來源 IList) |
AddIndex(PropertyDescriptor) |
將 PropertyDescriptor 加入用來搜尋的索引中。 |
AddNew() |
將新的項目加入至清單中。 |
ApplySort(PropertyDescriptor, ListSortDirection) |
根據 PropertyDescriptor 和 ListSortDirection 來排序清單。 |
Clear() |
從 IList 中移除所有項目。 (繼承來源 IList) |
Contains(Object) |
判斷 IList 是否包含特定值。 (繼承來源 IList) |
CopyTo(Array, Int32) |
從特定的 ICollection 索引開始,將 Array 的項目複製到 Array。 (繼承來源 ICollection) |
Find(PropertyDescriptor, Object) |
傳回具有指定 PropertyDescriptor 的列索引。 |
GetEnumerator() |
傳回逐一查看集合的列舉值。 (繼承來源 IEnumerable) |
IndexOf(Object) |
判斷 IList 中指定項目的索引。 (繼承來源 IList) |
Insert(Int32, Object) |
將項目插入位於指定索引的 IList。 (繼承來源 IList) |
Remove(Object) |
從 IList 移除特定物件之第一個符合的元素。 (繼承來源 IList) |
RemoveAt(Int32) |
移除在指定索引處的 IList 項目。 (繼承來源 IList) |
RemoveIndex(PropertyDescriptor) |
從用來搜尋的索引中移除 PropertyDescriptor。 |
RemoveSort() |
移除任何使用 ApplySort(PropertyDescriptor, ListSortDirection) 的套用排序。 |
事件
ListChanged |
發生於清單變更或清單項目變更時。 |
擴充方法
Cast<TResult>(IEnumerable) |
將 IEnumerable 的項目轉換成指定的型別。 |
OfType<TResult>(IEnumerable) |
根據指定的型別來篩選 IEnumerable 的項目。 |
AsParallel(IEnumerable) |
啟用查詢的平行化作業。 |
AsQueryable(IEnumerable) |
將 IEnumerable 轉換成 IQueryable。 |