Control.BindingContext Propiedad
Importante
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Obtiene o establece la plantilla BindingContext para el 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; }[System.ComponentModel.Browsable(false)]
public virtual System.Windows.Forms.BindingContext? BindingContext { get; set; }[<System.ComponentModel.Browsable(false)>]
member this.BindingContext : System.Windows.Forms.BindingContext with get, setPublic Overridable Property BindingContext As BindingContextBindingContext del control.
- Atributos
En el ejemplo de código siguiente se crean cuatro Binding objetos para enlazar cinco controles, uno DateTimePicker y cuatro TextBox controles, a varios orígenes de datos. BindingContext A continuación, se usa para obtener para BindingManagerBase cada origen de datos.
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
de BindingContext Control se usa para devolver un único BindingManagerBase para todos los controles enlazados a datos contenidos en .Control BindingManagerBase mantiene sincronizados todos los controles enlazados al mismo origen de datos. Por ejemplo, al establecer la Position propiedad de especifica BindingManagerBase el elemento de la lista subyacente a la que apuntan todos los controles enlazados a datos.
Para obtener más información sobre cómo crear un nuevo BindingContext y asignarlo a la BindingContext propiedad , vea .BindingContext
Al invalidar la BindingContext propiedad en una clase derivada, utilice la propiedad de BindingContext la clase base para extender la implementación base. De lo contrario, debe proporcionar toda la implementación. No es necesario invalidar los get descriptores de acceso y set de la BindingContext propiedad; solo se puede invalidar uno si es necesario.
| Producto | Versiones |
|---|---|
| .NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8 |
| Windows Desktop | 3.0, 3.1, 5, 6, 7 |