Export (0) Print
Expand All
Expand Minimize

Control.BindingContext Property

Gets or sets the BindingContext for the control.

[Visual Basic]
Public Overridable Property BindingContext As BindingContext
[C#]
public virtual BindingContext BindingContext {get; set;}
[C++]
public: __property virtual BindingContext* get_BindingContext();
public: __property virtual void set_BindingContext(BindingContext*);
[JScript]
public function get BindingContext() : BindingContext;
public function set BindingContext(BindingContext);

Property Value

A BindingContext for the control.

Remarks

The BindingContext object of a Control is used to return a single BindingManagerBase object for all data-bound controls contained by the Control. The BindingManagerBase object keeps all controls that are bound to the same data source synchronized. For example, setting the Position property of the BindingManagerBase specifies the item in the underlying list that all data-bound controls point to.

For more information about creating a new BindingContext and assigning it to the BindingContext property, see the BindingContext.

Notes to Inheritors:  When overriding the BindingContext property in a derived class, use the base class's BindingContext property to extend the base implementation. Otherwise, you must provide all the implementation. You are not required to override both the get and set accessors of the BindingContext property; you can override only one if needed.

Example

[Visual Basic, C#, C++] The following example creates four Binding objects to bind five controls, a DateTimePicker and four TextBox controls, to several data sources. The BindingContext is then used to get the BindingManagerBase for each data source.

[Visual Basic] 
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


[C#] 
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");
}


[C++] 
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(S"Text", ds, S"customers.custName"));
    text2->DataBindings->Add(new Binding(S"Text", ds, S"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(S"Value", ds, S"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 __gc *b = new Binding (S"Text", ds, S"customers.custToOrders.OrderAmount");
    b->Parse += new ConvertEventHandler(this, &Form1::CurrencyStringToDecimal);
    b->Format += new ConvertEventHandler(this, &Form1::DecimalToCurrencyString);
    text3->DataBindings->Add(b);

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

   /* Get the BindingManagerBase for the Orders table using the 
  RelationName. */ 
    bmOrders = this->BindingContext->get_Item(ds, S"customers.CustToOrders");

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

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

See Also

Control Class | Control Members | System.Windows.Forms Namespace | BindingContextChanged | Binding | BindingManagerBase

Show:
© 2014 Microsoft