How to open a WPF Popup when RadioButton checked? - wpf

Question

I have a RadioButton and a Popup. I want to open Popup when checked RadioButton and close Popup when LostFocus of it, without unchecked RadioButton.
I use this code.
<StackPanel>
<RadioButton x:Name="RadioButtonSave" IsChecked="{Binding IsSave}">Save</RadioButton>
<RadioButton x:Name="RadioButtonNotSave" LostFocus="RadioButtonNotSave_OnLostFocus" IsChecked="{Binding IsSave,Converter={StaticResource ToNegativeConverter}}">Not Save</RadioButton>
</StackPanel>
<Popup x:Name="Popup" IsOpen="{Binding IsChecked,ElementName=RadioButtonNotSave}" StaysOpen="True" Placement="Left" PlacementTarget="{Binding ElementName=RadioButtonNotSave}"></Popup>
private void RadioButtonNotSave_OnLostFocus(object sender, RoutedEventArgs e)
{
Popup.IsOpen = false;
}
It is open popup when checked but when lostfocuse unchecked radiobutton.
I set Mode=OneWay for IsOpen , it is open popup and don't unchecked radionButton in lost focuse, but it worked for one time.

Answer 1

Here is a way of doing it only in XAML:
<Window x:Class="RadioButtonAndPopup.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<StackPanel>
<StackPanel.Resources>
<Style TargetType="{x:Type RadioButton}">
<EventSetter Event="Click" Handler="EventSetter_OnHandler"/>
</Style>
</StackPanel.Resource>
<RadioButton x:Name="RadioBtn" Content="TestPopup"/>
<Popup x:Name="myPopup" IsOpen="{Binding IsChecked, ElementName=RadioBtn, Mode=OneWay}" Placement="Mouse" StaysOpen="False">
<Border Background="LightBlue">
<TextBlock>Popup</TextBlock>
</Border>
</Popup>
</StackPanel>
</Grid>
Setting StaysOpen false, you will be able to close the Popup by clicking anywhere outside it.
Update 1:
Add this in the StackPanel.Resources and name your Popup.
<Style TargetType="{x:Type RadioButton}">
<EventSetter Event="Click" Handler="EventSetter_OnHandler"/>
</Style>
And this will be added to codebehind:
private void EventSetter_OnHandler(object sender, RoutedEventArgs e)
{
myPopup.IsOpen = true;
}
So now the Popup will be opened on that Click event and not from the IsChecked binding.

Answer 2

Try this instead:
private void RadioButtonNotSave_OnLostFocus(object sender, RoutedEventArgs e)
{
IsChecked = false;
}