Question

I have one textbox and one button. The Button Command should change the property which is binded to the TextBox.

But I don’t see any visual changes after command execution.
I think it easy question related to wpf binding

Please help me with this issue

Source of app:

<UserControl.DataContext>
    <local:SampleViewModel />
</UserControl.DataContext>
<Grid>
    <StackPanel>
        <TextBox Height="23" Width="120" Text="{Binding MyName}"  />
        <Button Content="Click" Command="{Binding ButtonCommand}" />
    </StackPanel>
</Grid>

ViewModel:

Private _myName As String
Public Property MyName As String
  Get
    Return _myName
  End Get
  Set(value As String)
    _myName = value
      OnPropertyChanged("MyName")
  End Set
End Property

Public _buttonCommand As DelegateCommand
Public ReadOnly Property ButtonCommand As DelegateCommand
Get
  Return If(_buttonCommand IsNot Nothing, _buttonCommand, 
  New DelegateCommand(AddressOf Execute, AddressOf CanExecute))
End Get
End Property

Private Sub Execute()
  MyName = "Executed"
End Sub

Private Function CanExecute() As Boolean
  Return True
End Function

Public Event PropertyChanged As PropertyChangedEventHandler
Private Sub OnPropertyChanged(propertyName As String)
  RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
End Sub

Answer 1

Do the following:

1.
Class MainWindow
Implements INotifyPropertyChanged

2 . In Public Sub New() make sure you write Me.DataContext = Me to set the DataContext

Note: Ignore step 2 if you’re using a ViewModel and setting it in XAML

3 . Modify the ProperyChanged like this:
Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

Only after implementing INotifyPropertyChanged correctly will the Binding correctly refresh the MyName property after the PropertyChanged event