How to: Create a Binding in Code
This example shows how to create and set a Binding in code.
Example
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
Get
Return Me._myDataProperty
End Get
Set(ByVal value As String)
Me._myDataProperty = value
Me.OnPropertyChanged("MyDataProperty")
End Set
End Property
' Fields
Private _myDataProperty As String
End Class
public class MyData : INotifyPropertyChanged
{
private string myDataProperty;
public MyData() { }
public MyData(DateTime dateTime)
{
myDataProperty = "Last bound time was " + dateTime.ToLongTimeString();
}
public String MyDataProperty
{
get { return myDataProperty; }
set
{
myDataProperty = value;
OnPropertyChanged("MyDataProperty");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string info)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(info));
}
}
}
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)
//make a new source
MyData myDataObject = new MyData(DateTime.Now);
Binding myBinding = new Binding("MyDataProperty");
myBinding.Source = myDataObject;
myText.SetBinding(TextBlock.TextProperty, myBinding);
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)
//make a new source
MyData myDataObject = new MyData(DateTime.Now);
Binding myBinding = new Binding("MyDataProperty");
myBinding.Source = myDataObject;
BindingOperations.SetBinding(myText, TextBlock.TextProperty, myBinding);