Inverted bool to radio button from dataContext to userControl

Question

How can I bind an inverted value of a bool in my xaml?

I know, I know, there are a lot of q&a about this, but there aren't any about a specific case: when the converter is in a view model and the radio button in a user control.

how can I correctly refer to the main window view model data context? In other case I used the code I've posted, but in this case I don't get how to use it.

UPDATE CODE:

namespace ***.ViewModel
{
    [ValueConversion(typeof(bool), typeof(bool))]
    public class InverseBooleanConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter,
            System.Globalization.CultureInfo culture)
        {
            if (targetType != typeof(bool))
                throw new InvalidOperationException("The target must be a boolean");
            return !(bool)value;
        }
        public object ConvertBack(object value, Type targetType, object parameter,
            System.Globalization.CultureInfo culture)
        {
            throw new NotSupportedException();
        }
    }
        class MainWindowViewModel : MyClass.UtilityClasses.ViewModelBase
    {
        public MainWindowViewModel(){
            SaveCommand = new DelegateCommand(SaveData, CanSave );
            UndoCommand = new DelegateCommand(UndoActions, CanSave);
            [...]

    }
....
}

ANOTHER CODE UPDATE:

In my xaml, I have a devexpress GridControl where I list my observableCollection from db. When I click one element, a layout group is populated with the relative data.

In this layout group, I have:

<StackPanel Margin="0" Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Left">
    <RadioButton Content="{DynamicResource Locale}" Margin="10,0,0,0" x:Name="rd_LOCALE" VerticalAlignment="Center" IsChecked="{Binding Path=REMOTO, Converter={StaticResource InverseBooleanConverter}}" GroupName="Location" Panel.ZIndex="9" TabIndex="10" />
    <RadioButton Content="{DynamicResource Remoto}" Margin="10,0,6,0" x:Name="rd_REMOTO" VerticalAlignment="Center" IsChecked="{Binding REMOTO}" GroupName="Location" Panel.ZIndex="10" TabIndex="11" Tag="PRISMA" />
</StackPanel>

WhenI change from one record to another, the converter gives me error... why? It fails the "if (targetType != typeof(bool))" row. So I tried to change that like:

if (value.getType() != typeof(bool))

but in this way, without fails nothing in the code, it put the wrong value in the radiobutton!

Surely you could use a value converter to invert the boolean value? — Steven Wood, Sep 23 '14 at 14:48
D'oh just saw that sorry! is your converter defined in the controls resources section? — Steven Wood, Sep 23 '14 at 14:50
it is defined in the MainWindowViewModel.cs. The radio button is in a UserControl inclued in MainWindowView.xaml. I've copied the converter from other question. — Piero Alberto, Sep 23 '14 at 14:52

score 1 · Accepted Answer · answered Sep 23 '14 at 14:56

1

You need to make sure that the value converter is referenced in the XAML

<UserControl.Resources>
    <myproject:InverseBooleanConverter x:Key="InverseBooleanConverter" />
</UserControl.Resources>

where my project is the namespace in which the value converter class is defined

answered Sep 23 '14 at 14:56

Steven Wood

2,675
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51

in this way? and then? – Piero Alberto Sep 23 '14 at 14:59
1

is the InverseBooleanConverter a class that is defined within the MainWindowViewModel class? – Steven Wood Sep 23 '14 at 15:00
yes, like in this question (the accpeted answer); http://stackoverflow.com/questions/1039636/how-to-bind-inverse-boolean-properties-in-wpf – Piero Alberto Sep 23 '14 at 15:03
user control xaml: [..] IsChecked="{Binding Path=REMOTO, Converter={StaticResource InverseBooleanConverter}}" [..] – Piero Alberto Sep 23 '14 at 15:04
1

When you type in – Steven Wood Sep 23 '14 at 15:05
it says that nested properties are not supported. – Piero Alberto Sep 23 '14 at 15:08
2

create a new class file in the same namespace, then copy your value converter code into that class, (making sure you delete the existing public class Class1 code) then try it as – Steven Wood Sep 23 '14 at 15:10
Ok, I'll try! I've posted the code of converter, anyway! :) – Piero Alberto Sep 23 '14 at 15:11
I don't know why, but now it works, I can see it from xaml and it is called!! :D now the problem is that the converter throws error when I change the record to be detailed. It fails the if (targetType != typeof(bool)) – Piero Alberto Sep 24 '14 at 06:42
I have detailed my question with the new problem. – Piero Alberto Sep 24 '14 at 07:06
i have explained bad: it doesn't throw an error, it fails the if and go inside the if code. Like it wasn't a bool value. – Piero Alberto Sep 24 '14 at 08:27
1

put a break point on the line "if (targetType != typeof(bool))" and make sure that the target type is actually a boolean when passing to the conveter – Steven Wood Sep 24 '14 at 08:41
with a new converter (http://stackoverflow.com/questions/3361362/wpf-radiobutton-two-binding-to-boolean-value) and different groupname to the radiobuttons (why??) it seems to work! what do you think? – Piero Alberto Sep 24 '14 at 08:57
1

My huess would be the attributes [ValueConversion(typeof(bool), typeof(bool))] were messing things up, I have neve needed these attributes so not sure why they are necessary – Steven Wood Sep 24 '14 at 09:23
and about the different name group? with the same namegroup, it doesn't work well! bah... anyway, you are bery kind... thank you! =) – Piero Alberto Sep 24 '14 at 09:36

Inverted bool to radio button from dataContext to userControl

1 Answers1