How to: Create a Binding in Code


This example shows how to create and set a Binding in code.


The FrameworkElement class and the FrameworkContentElement class both expose a SetBinding method. If you are binding an element that inherits either of these classes, you can call the SetBinding method directly.

The following example creates a class named, MyData, which contains a property named MyDataProperty.

Public Class MyData
    Implements INotifyPropertyChanged

    ' Events
    Public Event PropertyChanged As PropertyChangedEventHandler _
        Implements INotifyPropertyChanged.PropertyChanged

    ' Methods
    Public Sub New()
    End Sub

    Public Sub New(ByVal dateTime As DateTime)
        Me.MyDataProperty = ("Last bound time was " & dateTime.ToLongTimeString)
    End Sub

    Private Sub OnPropertyChanged(ByVal info As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
    End Sub

    ' Properties
    Public Property MyDataProperty As String
            Return Me._myDataProperty
        End Get
        Set(ByVal value As String)
            Me._myDataProperty = value
        End Set
    End Property

    ' Fields
    Private _myDataProperty As String
End Class

The following example shows how to create a binding object to set the source of the binding. The example uses SetBinding to bind the Text property of myText, which is a TextBlock control, to MyDataProperty.

Dim data1 As New MyData(DateTime.Now)
Dim binding1 As New Binding("MyDataProperty")
binding1.Source = data1
Me.myText.SetBinding(TextBlock.TextProperty, binding1)

For the complete code sample, see Code-only Binding Sample.

Instead of calling SetBinding, you can use the SetBinding static method of the BindingOperations class. The following example, calls BindingOperations.SetBinding instead of FrameworkElement.SetBinding to bind myText to myDataProperty.

Dim myDataObject As New MyData(DateTime.Now)
Dim myBinding As New Binding("MyDataProperty")
myBinding.Source = myDataObject
BindingOperations.SetBinding(myText, TextBlock.TextProperty, myBinding)