INotifyPropertyChanged.PropertyChanged Event
Occurs when a property value changes.
Assembly: System (in System.dll)
The PropertyChanged event can indicate all properties on the object have changed by using either Nothing or String.Empty as the property name in the PropertyChangedEventArgs.
The following code example demonstrates how to implement the PropertyChanged event of the INotifyPropertyChanged interface.
' This class implements a simple customer type ' that implements the IPropertyChange interface. Public Class DemoCustomer Implements INotifyPropertyChanged ' These fields hold the values for the public properties. Private idValue As Guid = Guid.NewGuid() Private customerNameValue As String = String.Empty Private phoneNumberValue As String = String.Empty Public Event PropertyChanged As PropertyChangedEventHandler _ Implements INotifyPropertyChanged.PropertyChanged Private Sub NotifyPropertyChanged(ByVal info As String) RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info)) End Sub ' The constructor is private to enforce the factory pattern. Private Sub New() customerNameValue = "Customer" phoneNumberValue = "(555)555-5555" End Sub ' This is the public factory method. Public Shared Function CreateNewCustomer() As DemoCustomer Return New DemoCustomer() End Function ' This property represents an ID, suitable ' for use as a primary key in a database. Public ReadOnly Property ID() As Guid Get Return Me.idValue End Get End Property Public Property CustomerName() As String Get Return Me.customerNameValue End Get Set(ByVal value As String) If Not (value = customerNameValue) Then Me.customerNameValue = value NotifyPropertyChanged("CustomerName") End If End Set End Property Public Property PhoneNumber() As String Get Return Me.phoneNumberValue End Get Set(ByVal value As String) If Not (value = phoneNumberValue) Then Me.phoneNumberValue = value NotifyPropertyChanged("PhoneNumber") End If End Set End Property End Class
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.