WPF IValueconverter is Not Firing When Click the radio button

Question

Here is my xaml below. The DisplayUnitConverter is not firing when I click the radio buttons. Can someone assist me to see what I am doing wrong? I have initialize the Element name in the SpinEdit control to the Radio Control name.

<Window x:Class="DisplayUnitClient.MainWindow"
xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
xmlns:dxn="http://schemas.devexpress.com/winfx/2008/xaml/navbar"
xmlns:dxlc="http://schemas.devexpress.com/winfx/2008/xaml/layoutcontrol"
xmlns:DisplayUnitClient ="clr-namespace:DisplayUnitClient"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<DisplayUnitClient:DisplayUnitConverter x:Key="DisplayUnitConverter" />
</Window.Resources>
<Grid>
<dxe:SpinEdit x:Name="spinEditMaxHatchSpeed" Height="{Binding ActualHeight, ElementName=label}" AllowDefaultButton="False" Value="{Binding Path=MaxHatchSpeed, Mode=TwoWay}" Margin="0,0,0,285">
<dxe:ButtonInfo IsLeft="True" Content="<" Command="{Binding SpinDownCommand, RelativeSource={RelativeSource AncestorType={x:Type dxe:SpinEdit}, Mode=FindAncestor}}"/>
<dxe:ButtonInfo Content=">" Command="{Binding SpinUpCommand, RelativeSource={RelativeSource AncestorType={x:Type dxe:SpinEdit}, Mode=FindAncestor}}"/>
</dxe:SpinEdit>
<GroupBox x:Name="groupBoxDisplaySettings" Header="Display Units" HorizontalAlignment="Stretch" VerticalAlignment="Top" FontSize="16" Margin="0,39,10,0">
<StackPanel x:Name="stackPanelDisplayUnit" HorizontalAlignment="Left" VerticalAlignment="Center" Orientation="Vertical" Width="349" >
<Label Content="Max Hatch Speed:" />
<RadioButton Margin="0,0,20,0" Content="Millimeters" Name="MillimeterDisplayUnitButton" GroupName="DisplayUnits" Click="DisplayUnitMode_Clicked" Tag="0" IsChecked="{Binding Path=MaxHatchSpeed, ElementName=spinEditMaxHatchSpeed, Converter={StaticResource DisplayUnitConverter}, Mode=TwoWay}"/>
<RadioButton Content="Inches" Name="InchesDisplayUnitButton" GroupName="DisplayUnits" Click="DisplayUnitMode_Clicked" Tag="1" IsChecked="{Binding Path=MaxHatchSpeed, ElementName=spinEditMaxHatchSpeed, Converter={StaticResource DisplayUnitConverter}, Mode=TwoWay}"/>
</StackPanel>
</GroupBox>
</Grid>
</Window>

Answer 1

Don't know how you input your XAML but in the forum it is unreadable and that stops us from helping.

Answer 2

Hi, you bind all CheckBoxes in GroupBox to the same property and use Click event. That can create unpredictable effects. Bind only one Checkbox (in GroupBox) and use setter in binded property instead of click event. Try following demo:

XAML:

<Window x:Class="Window005"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        xmlns:local="clr-namespace:WpfApp1.WpfApp005"
        mc:Ignorable="d"
        Title="Window005" Height="450" Width="800">
  <Window.DataContext>
    <local:ViewModel/>
  </Window.DataContext>
  <Window.Resources>
    <local:DisplayUnitConverter x:Key="DisplayUnitConverter" />
  </Window.Resources>
  <StackPanel>
    <GroupBox Header="Display Units" 
              HorizontalAlignment="Stretch" 
              VerticalAlignment="Top" 
              FontSize="16" Margin="0,39,10,0">
      <StackPanel HorizontalAlignment="Left" 
                  VerticalAlignment="Center" 
                  Orientation="Vertical" 
                  Width="349" >
        <Label Content="Max Hatch Speed:" />
        <RadioButton Content="Millimeters" 
                     GroupName="DisplayUnits" 
                     IsChecked="{Binding Path=MaxHatchSpeed, Converter={StaticResource DisplayUnitConverter}, Mode=TwoWay}"/>
        <RadioButton Content="Inches" 
                     GroupName="DisplayUnits"/>
      </StackPanel>
    </GroupBox>
    <StackPanel Orientation="Horizontal" Margin="5">
      <Label Content="MaxHatchSpeed: "/>
      <TextBlock Text="{Binding MaxHatchSpeed}" Margin="3"/>
    </StackPanel>
  </StackPanel>
</Window> 

Code:

Imports System.ComponentModel
Imports System.Globalization
Imports System.Runtime.CompilerServices

Public Class Window005

End Class

Namespace WpfApp005
  Public Class ViewModel
    Implements INotifyPropertyChanged

    Private _maxHatchSpeed As Double = 1
    Public Property MaxHatchSpeed As Double
      Get
        Return Me._maxHatchSpeed
      End Get
      Set(value As Double)
        If value >= 0 AndAlso value <= 100 Then
          Me._maxHatchSpeed = value
          OnPropertyChanged()
        End If
      End Set
    End Property

    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged
    Private Sub OnPropertyChanged(<CallerMemberName> Optional propName As String = "")
      RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propName))
    End Sub
  End Class

  Public Class DisplayUnitConverter
    Implements IValueConverter

    Public Function Convert(value As Object, targetType As Type, parameter As Object, culture As CultureInfo) As Object Implements IValueConverter.Convert
      If CType(value, Double) = 1 Then Return True
      Return False
    End Function

    Public Function ConvertBack(value As Object, targetType As Type, parameter As Object, culture As CultureInfo) As Object Implements IValueConverter.ConvertBack
      If CType(value, Boolean) Then Return 1
      Return 25.4
    End Function
  End Class
End Namespace