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
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