WPF | Expander Event - wpf

Question

In my console I'm using two Expanders say(x & y)
by default it has been set 'IsExpanded = False'
once I click x then y should not be Expanded vice-versa
so please reply me with a code

Answer 1

Even if it is possible doing it in plain markup, it would probably better to use an attached behavior. Here an example:
class Toggle
{
Expander target;
public Toggle(Expander src,Expander target)
{
this.target = target;
src.Collapsed += new RoutedEventHandler(src_Collapsed);
src.Expanded += new RoutedEventHandler(src_Expanded);
}
void src_Expanded(object sender, RoutedEventArgs e)
{
target.IsExpanded = false;
}
void src_Collapsed(object sender, RoutedEventArgs e)
{
target.IsExpanded = true;
}
}
public static class ToggleExpanderBehavior
{
static List<Toggle> toggler = new List<Toggle>();
public static Expander GetTargetExpander(DependencyObject obj)
{
return (Expander)obj.GetValue(TargetExpanderProperty);
}
public static void SetTargetExpander(DependencyObject obj, string value)
{
obj.SetValue(TargetExpanderProperty, value);
}
// Using a DependencyProperty as the backing store for TargetName. This enables animation, styling, binding, etc...
public static readonly DependencyProperty TargetExpanderProperty =
DependencyProperty.RegisterAttached("TargetExpander", typeof(Expander), typeof(ToggleExpanderBehavior), new UIPropertyMetadata(null,new PropertyChangedCallback(OnTargetChanged)));
static void OnTargetChanged(DependencyObject depo, DependencyPropertyChangedEventArgs depa)
{
if (depa.NewValue!=null)
{
if (depo is Expander)
{
var exp = depo as Expander;
toggler.Add(new Toggle(exp,depa.NewValue as Expander));
}
}
}
}
You van attach this behavior in xaml like this:
<Expander x:Name="X" IsExpanded="True" local:ToggleExpanderBehavior.TargetExpander="{Binding ElementName=Y}" >
<TextBlock>Content 1</TextBlock>
</Expander>
<Expander x:Name="Y" IsExpanded="False" local:ToggleExpanderBehavior.TargetExpander="{Binding ElementName=X}">
<TextBlock>Content 2</TextBlock>
</Expander>
</StackPanel>
and you have the toggle on.

Answer 2

This may help: Just register the expanded event for all your expander items (all the same event). If you open one, all others are closed:
private void expander_Expanded(object sender, RoutedEventArgs e)
{
SPExpander.Children.OfType<Expander>()
.All<Expander>(expander =>
{
if ((Expander)sender != expander)
expander.IsExpanded = false;
else
expander.IsExpanded = true;
return true;
});
}
Hope this solve you problem...

Answer 3

I would just Bind the IsExpanded property of one expander to the IsExpanded property on the other, then you just need to supply a value converter that inverts the value
public class BoolInverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var b = value as bool?;
return !b;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
var b = value as bool?;
return !b;
}
}