Binding IsChecked property of RadioButton inside ItemsControl - wpf

Question

I have ItemsControls with items binded from CollectionViewSource.
<ItemsControl ItemsSource="{Binding Source={StaticResource VisibleFlagsImageSourcePathView}}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<r:RibbonRadioButton SmallImageSource="{Binding}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
And another control outsite:
<TextBox Text="{Binding Path=SelectedCountryCode" />
What I am trying to accomplish is whenever I change the value of the TextBox I want the corresponding RibbonRadioButton property IsChecked set to true or false.

Answer 1

What you need to do is create a ViewModel with two properties.
class MyViewModel
{
// Bind this to TextBox
public String SelectedCountryCode { get; set; }
// Bind this to ItemsControl
public ObservableCollection<Object> VisibleFlagsImageSourcePath { get; set; }
}
// Note I have omitted implementation of `INotifyPropertyChanged`. But, you will need to implement it.
And monitor the SelectedCountryCode, and whenever it changes, change appropriate value in VisibleFlagsImageSourcePath collection.

Answer 2

Radio buttons represent enumerated values. A text box in this case would represent an open value. What you seem to want is a set of open values as well as a pre-set selection of enumerated values. The control that best represents this is a combo box.
If you decide to continue with the radio button/text box approach, you can adapt the method people use to bind radio buttons to an enumerated value, except use a string field/string field type converter instead of an enum field/enum field type converter.
See this answer for how to bind to enums: How to bind RadioButtons to an enum?
To adapt this to strings, simply make a class called KnownStringToBooleanConverter (note that this is an identical implementation to EnumToBooleanConverter):
public class KnownStringToBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value.Equals(parameter);
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value.Equals(true) ? parameter : Binding.DoNothing;
}
}
Also create a type with your known strings (similar to how you would create an enum):
public static class KnownCountryCodes
{
// Note: I'm guessing at these codes...
public const string England = "EN";
public const string Japan = "JP";
}
Then bind to this in a similar way:
<RadioButton IsChecked="{Binding Path=SelectedCountryCode, Converter={StaticResource KnownStringToBooleanConverter}, ConverterParameter={x:Static local:KnownCountryCodes.England}}" />
<RadioButton IsChecked="{Binding Path=SelectedCountryCode, Converter={StaticResource KnownStringToBooleanConverter}, ConverterParameter={x:Static local:KnownCountryCodes.Japan}}" />
If you want all your controls to cross-populate, then you'll need to implement INotifyPropertyChanged in your view model:
public class MyViewModel : INotifyPropertyChanged
{
// Bind this to TextBox and radio buttons. Populate the radio buttons manually
public string SelectedCountryCode
{
get
{
return selectedCountryCode;
}
set
{
selectedCountryCode = value;
RaiseNotifyPropertyChanged("SelectedCountryCode");
}
}
/* Todo: Implement NotifyPropertyChanged and RaiseNotifyPropertyChanged here */
private string selectedCountryCode;
}
When a custom value (that isn't in the list) is entered, the radio buttons will all dim. When you type in a value that is from the list, the corresponding radio button will light up. When you select a correct radio button, the value will be changed in the text box.
This View/ViewModel stuff is called MVVM.
See: http://msdn.microsoft.com/en-us/magazine/dd419663.aspx