CODEWITHSUNDEEP
wpfdata-bindingcheckboxisenabled
SiN
SiN

Reputation: 3754

WPF element databinding for IsEnabled (but for false)

I'm a starter in WPF, and there's something I can't seem to figure out.

I have a CheckBox that I would like to disable when a RadioButton is not selected. My current syntax is:

<CheckBox IsEnabled="{Binding ElementName=rbBoth, Path=IsChecked}">Show all</CheckBox>

So basically, I want IsEnabled to take the opposite value than the binding expression I'm currently supplying.

How can I do this? Thanks.

Upvotes: 5

Views: 15744

Answers (4)

Amsakanna
Amsakanna

Reputation: 12934

Your current syntax already serves your need. It will disable the checkbox if the radiobutton is not checked.

If you really want to invert the scenario, all you need is a Converter. Take a look at this sample.

Upvotes: 0

Meysam Chegini
Meysam Chegini

Reputation: 999

<CheckBox>
                    <CheckBox.Style>
                        <Style TargetType="CheckBox">
                            <Setter Property="Visibility" Value="Visible" />
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding IsShowName }" Value="true">
                                    <Setter Property="Visibility" Value="Collapsed" />
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </CheckBox.Style>
  </CheckBox>

Upvotes: 3

Istu7
Istu7

Reputation: 1

How about this one:

Create a converter for booleans:

class BooleanValueInverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (!(parameter is IValueConverter))
        {
            if (value is bool)
                return !(bool)value;
            else
                return DependencyProperty.UnsetValue;
        }
        else
        {
            IValueConverter converter = (IValueConverter)parameter;
            if (value is bool)
            {
                bool input = !(bool)value;
                return converter.Convert(input, targetType, null, culture);
            }
            else
            {
                return DependencyProperty.UnsetValue;
            }
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

in the xaml import the namespace where the inverter class is implemented:

xmlns:util="clr-namespace:MyApp.Utilities"

In the resource section add reference the inverter class:

<util:BooleanValueInverter x:Key="Inverter" />

And then just simply use it like this:

<TextBox Text="{Binding Path=TextProperty}" IsEnabled="{Binding SomeBoolPropertyToInvert, Converter={StaticResource Inverter}}"/>

Upvotes: 0

Josh
Josh

Reputation: 69262

You need to use what's called a value converter (a class that implements IValueConverter.) A very basic example of such a class is shown below. (Watch for clipping...)

public class NegateConverter : IValueConverter
{

    public object Convert( object value, Type targetType, object parameter, CultureInfo culture )
    {
        if ( value is bool ) {
            return !(bool)value;
        }
        return value;
    }

    public object ConvertBack( object value, Type targetType, object parameter, CultureInfo culture )
    {
        if ( value is bool ) {
            return !(bool)value;
        }
        return value;
    }

}

Then to include it in your XAML you would do something like:

<UserControl xmlns:local="clr-namespace:MyNamespace">
    <UserControl.Resources>
        <local:NegateConverter x:Key="negate" />
    </UserControl.Resources>

    ...
    <CheckBox IsEnabled="{Binding IsChecked, ElementName=rbBoth, Converter={StaticResource negate}}"
              Content="Show all" />

</UserControl>

Upvotes: 20

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