IsEqualConverter

Article
03/01/2023

The IsEqualConverter is a one way converter that returns a bool indicating whether the binding value is equal to another specified value.

The Convert method returns true when the binding value is equal to the supplied ConverterParameter.

The ConvertBack method is not supported. For the opposite behavior see the IsNotEqualConverter.

BaseConverter Properties

The following properties are implemented in the base class, public abstract class BaseConverter:

Property	Description
`DefaultConvertReturnValue`	Default value to return when `IValueConverter.Convert(object?, Type, object?, CultureInfo?)` throws an `Exception`. This value is used when CommunityToolkit.Maui.Options`.ShouldSuppressExceptionsInConverters` is set to `true`.
`DefaultConvertBackReturnValue`	Default value to return when `IValueConverter.ConvertBack(object?, Type, object?, CultureInfo?)` throws an `Exception`. This value is used when CommunityToolkit.Maui.Options`.ShouldSuppressExceptionsInConverters` is set to `true`.

ICommunityToolkitValueConverter Properties

The following properties are implemented in the public interface ICommunityToolkitValueConverter:

Property	Type	Description
`DefaultConvertReturnValue`	`object?`	Default value to return when `IValueConverter.Convert(object?, Type, object?, CultureInfo?)` throws an `Exception`. This value is used when CommunityToolkit.Maui.Options`.ShouldSuppressExceptionsInConverters` is set to `true`.
`DefaultConvertBackReturnValue`	`object?`	Default value to return when `IValueConverter.ConvertBack(object?, Type, object?, CultureInfo?)` throws an `Exception`. This value is used when CommunityToolkit.Maui.Options`.ShouldSuppressExceptionsInConverters` is set to `true`.

Syntax

XAML

Including the XAML namespace

In order to use the toolkit in XAML the following xmlns needs to be added into your page or view:

xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"

Therefore the following:

<ContentPage
    x:Class="CommunityToolkit.Maui.Sample.Pages.MyPage"
    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml">

</ContentPage>

Would be modified to include the xmlns as follows:

<ContentPage
    x:Class="CommunityToolkit.Maui.Sample.Pages.MyPage"
    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit">

</ContentPage>

Using the IsEqualConverter

The IsEqualConverter can be used as follows in XAML:

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
             x:Class="CommunityToolkit.Maui.Sample.Pages.Converters.IsEqualConverterPage">

    <ContentPage.Resources>
        <ResourceDictionary>
            <toolkit:IsEqualConverter x:Key="IsEqualConverter" />
        </ResourceDictionary>
    </ContentPage.Resources>

    <Label Text="The value is equal to 100"
           IsVisible="{Binding MyValue, Converter={StaticResource IsEqualConverter}, ConverterParameter=100}" />

</ContentPage>

C#

The IsEqualConverter can be used as follows in C#:


class IsEqualConverterPage : ContentPage
{
    public IsEqualConverterPage()
    {
        var label = new Label { Text = "The value is equal to 100" };

		label.SetBinding(
			Label.IsVisibleProperty,
			new Binding(
				nameof(ViewModels.MyValue),
				converter: new IsEqualConverter(),
				converterParameter: 100));

		Content = label;
    }
}

C# Markup

Our CommunityToolkit.Maui.Markup package provides a much more concise way to use this converter in C#.

using CommunityToolkit.Maui.Markup;

class IsEqualConverterPage : ContentPage
{
    public IsEqualConverterPage()
    {
        Content = new Label { Text = "The value is equal to 100" }
            .Bind(
                Label.IsVisibleProperty,
                static (ViewModel vm) => vm.MyValue,
                converter: new IsEqualConverter(),
                converterParameter: 100);
    }
}

Examples

You can find an example of this converter in action in the .NET MAUI Community Toolkit Sample Application.

API

You can find the source code for IsEqualConverter over on the .NET MAUI Community Toolkit GitHub repository.

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