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BindingOperations.GetBindingExpression Method

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Definition

Namespace:
System.Windows.Data
Assembly:
PresentationFramework.dll

Returns the BindingExpression object associated with the specified binding target property on the specified object.

public:
 static System::Windows::Data::BindingExpression ^ GetBindingExpression(System::Windows::DependencyObject ^ target, System::Windows::DependencyProperty ^ dp);
public static System.Windows.Data.BindingExpression GetBindingExpression (System.Windows.DependencyObject target, System.Windows.DependencyProperty dp);
static member GetBindingExpression : System.Windows.DependencyObject * System.Windows.DependencyProperty -> System.Windows.Data.BindingExpression
Public Shared Function GetBindingExpression (target As DependencyObject, dp As DependencyProperty) As BindingExpression

Parameters

target
DependencyObject

The binding target object where dp is.

dp
DependencyProperty

The binding target property from which to retrieve the BindingExpression object.

Returns

BindingExpression

The BindingExpression object associated with the given property or null if none exists. If a PriorityBindingExpression object is set on the property, the ActiveBindingExpression is returned.

Exceptions

ArgumentNullException

The target and dp parameters cannot be null.

Examples

The following example shows the implementation of a Click event handler that uses the GetBindingExpression method to obtain the BindingExpression and then calls the DataItem property to access the binding source object.

The TextBlock SavingsText is the binding target object and Text is the binding target property.

private void OnRentRaise(Object sender, RoutedEventArgs args)
{
  // Update bills
  System.Random random = new System.Random();
  double i = random.Next(10);
  BindingExpression bindingExpression =
    BindingOperations.GetBindingExpression(SavingsText, TextBlock.TextProperty);
  SDKSample.NetIncome sourceData = (SDKSample.NetIncome) bindingExpression.DataItem;
  sourceData.Rent = (int)((1 + i / 100) * (double)sourceData.Rent);
}

Private Sub OnRentRaise(ByVal sender As Object, ByVal args As RoutedEventArgs)
    Dim _random As New System.Random()
    Dim num1 As Double = _random.Next(10)
    Dim expression1 As BindingExpression = BindingOperations.GetBindingExpression(Me.SavingsText, TextBlock.TextProperty)
    Dim income1 As NetIncome = DirectCast(expression1.DataItem, NetIncome)
    income1.Rent = CInt(((1 + (num1 / 100)) * income1.Rent))
End Sub

Remarks

The BindingExpression object maintains the connection between the binding source and the binding target. You can obtain the BindingExpression object by calling this static method or by calling the GetBindingExpression method on a data-bound FrameworkElement or FrameworkContentElement object.

Applies to

See also