Control.BindingContext Control.BindingContext Control.BindingContext Control.BindingContext Property

Определение

Возвращает или задает значение BindingContext для элемента управления.Gets or sets the BindingContext for the control.

public:
 virtual property System::Windows::Forms::BindingContext ^ BindingContext { System::Windows::Forms::BindingContext ^ get(); void set(System::Windows::Forms::BindingContext ^ value); };
[System.ComponentModel.Browsable(false)]
public virtual System.Windows.Forms.BindingContext BindingContext { get; set; }
member this.BindingContext : System.Windows.Forms.BindingContext with get, set
Public Overridable Property BindingContext As BindingContext

Значение свойства

Свойство BindingContext элемента управления.A BindingContext for the control.

Реализации

Примеры

В следующем примере кода создаются четыре Binding объекта для привязки пяти элементов управления DateTimePicker , а также TextBox четырех элементов управления к нескольким источникам данных.The following code example creates four Binding objects to bind five controls, a DateTimePicker and four TextBox controls, to several data sources. Затем используется для BindingManagerBase получения для каждого источника данных. BindingContextThe BindingContext is then used to get the BindingManagerBase for each data source.

void BindControls()
{
   /* Create two Binding objects for the first two TextBox 
         controls. The data-bound property for both controls 
         is the Text property. The data source is a DataSet 
         (ds). The data member is a navigation path in the form: 
         "TableName.ColumnName". */
   text1->DataBindings->Add( gcnew Binding( "Text",ds,"customers.custName" ) );
   text2->DataBindings->Add( gcnew Binding( "Text",ds,"customers.custID" ) );

   /* Bind the DateTimePicker control by adding a new Binding. 
         The data member of the DateTimePicker is a navigation path:
         TableName.RelationName.ColumnName string. */
   DateTimePicker1->DataBindings->Add( gcnew Binding( "Value",ds,"customers.CustToOrders.OrderDate" ) );

   /* Add event delegates for the Parse and Format events to a 
         new Binding object, and add the object to the third 
         TextBox control's BindingsCollection. The delegates 
         must be added before adding the Binding to the 
         collection; otherwise, no formatting occurs until 
         the Current object of the BindingManagerBase for 
         the data source changes. */
   Binding^ b = gcnew Binding( "Text",ds,"customers.custToOrders.OrderAmount" );
   b->Parse += gcnew ConvertEventHandler( this, &Form1::CurrencyStringToDecimal );
   b->Format += gcnew ConvertEventHandler( this, &Form1::DecimalToCurrencyString );
   text3->DataBindings->Add( b );

   // Get the BindingManagerBase for the Customers table. 
   bmCustomers = this->BindingContext[ ds,"Customers" ];

   /* Get the BindingManagerBase for the Orders table using the 
         RelationName. */
   bmOrders = this->BindingContext[ds, "customers.CustToOrders"];

   /* Bind the fourth TextBox control's Text property to the
      third control's Text property. */
   text4->DataBindings->Add( "Text", text3, "Text" );
}
protected void BindControls()
{
   /* Create two Binding objects for the first two TextBox 
      controls. The data-bound property for both controls 
      is the Text property. The data source is a DataSet 
      (ds). The data member is a navigation path in the form: 
      "TableName.ColumnName". */
   text1.DataBindings.Add(new Binding
   ("Text", ds, "customers.custName"));
   text2.DataBindings.Add(new Binding
   ("Text", ds, "customers.custID"));
   
   /* Bind the DateTimePicker control by adding a new Binding. 
      The data member of the DateTimePicker is a navigation path:
      TableName.RelationName.ColumnName string. */
   DateTimePicker1.DataBindings.Add(new 
   Binding("Value", ds, "customers.CustToOrders.OrderDate"));

   /* Add event delegates for the Parse and Format events to a 
      new Binding object, and add the object to the third 
      TextBox control's BindingsCollection. The delegates 
      must be added before adding the Binding to the 
      collection; otherwise, no formatting occurs until 
      the Current object of the BindingManagerBase for 
      the data source changes. */
      Binding b = new Binding
      ("Text", ds, "customers.custToOrders.OrderAmount");
   b.Parse+=new ConvertEventHandler(CurrencyStringToDecimal);
   b.Format+=new ConvertEventHandler(DecimalToCurrencyString);
   text3.DataBindings.Add(b);

   // Get the BindingManagerBase for the Customers table. 
   bmCustomers = this.BindingContext [ds, "Customers"];

   /* Get the BindingManagerBase for the Orders table using the 
      RelationName. */ 
   bmOrders = this.BindingContext[ds, "customers.CustToOrders"];

   /* Bind the fourth TextBox control's Text property to the
   third control's Text property. */
   text4.DataBindings.Add("Text", text3, "Text");
}

Protected Sub BindControls()

   ' Create two Binding objects for the first two TextBox 
   '   controls. The data-bound property for both controls 
   '   is the Text property. The data source is a DataSet 
   '   (ds). The data member is the string 
   '   "TableName.ColumnName".
   text1.DataBindings.Add(New Binding _
      ("Text", ds, "customers.custName"))
   text2.DataBindings.Add(New Binding _
      ("Text", ds, "customers.custID"))
   
   ' Bind the DateTimePicker control by adding a new Binding. 
   '   The data member of the DateTimePicker is a 
   '   TableName.RelationName.ColumnName string.
   DateTimePicker1.DataBindings.Add(New Binding _
      ("Value", ds, "customers.CustToOrders.OrderDate"))

   ' Add event delegates for the Parse and Format events to a 
   '   new Binding object, and add the object to the third 
   '   TextBox control's BindingsCollection. The delegates 
   '   must be added before adding the Binding to the 
   '   collection; otherwise, no formatting occurs until 
   '   the Current object of the BindingManagerBase for 
   '   the data source changes.
   Dim b As Binding = New Binding _
      ("Text", ds, "customers.custToOrders.OrderAmount")
   AddHandler b.Parse,  New ConvertEventHandler(AddressOf CurrencyStringToDecimal)      
   AddHandler b.Format, New ConvertEventHandler(AddressOf DecimalToCurrencyString)
   text3.DataBindings.Add(b)

   ' Get the BindingManagerBase for the Customers table.
   bmCustomers = Me.BindingContext(ds, "Customers")

   ' Get the BindingManagerBase for the Orders table using the 
   '   RelationName.
   bmOrders = Me.BindingContext(ds, "customers.CustToOrders")

   ' Bind the fourth TextBox control's Text property to the
   ' third control's Text property.
   text4.DataBindings.Add("Text", text3, "Text")

End Sub

Комментарии

Объект BindingContext BindingManagerBase классаиспользуетсядлявозвратаControlодного объекта длявсехэлементовуправления,привязанныхкданным,содержащихсяв.ControlThe BindingContext of a Control is used to return a single BindingManagerBase for all data-bound controls contained by the Control. Объект BindingManagerBase поддерживает синхронизацию всех элементов управления, привязанных к одному источнику данных.The BindingManagerBase keeps all controls that are bound to the same data source synchronized. Например, задание Position свойства BindingManagerBase объекта определяет элемент в базовом списке, на который указывают все элементы управления с привязкой к данным.For example, setting the Position property of the BindingManagerBase specifies the item in the underlying list that all data-bound controls point to.

Дополнительные сведения о создании нового BindingContext и присвоении его BindingContext свойству см. в BindingContextразделе.For more information about creating a new BindingContext and assigning it to the BindingContext property, see the BindingContext.

Примечания для тех, кто наследует этот метод

При переопределении BindingContext свойства в производном классе используйте BindingContext свойство базового класса для расширения базовой реализации.When overriding the BindingContext property in a derived class, use the base class's BindingContext property to extend the base implementation. В противном случае необходимо предоставить всю реализацию.Otherwise, you must provide all the implementation. Переопределение get методов доступа и set для BindingContext свойства не требуется; при необходимости можно переопределить только одно из них.You are not required to override both the get and set accessors of the BindingContext property; you can override only one if needed.

Применяется к

Дополнительно