ListToStringConverter

The ListToStringConverter is a one way converter that returns a concatenation of the members of a collection, using the specified separator between each member.

The Convert method returns a concatenation of the members of a collection, using the specified separator between each member.

Note

Note that the separators can be supplied in the following ways:

1. As the ConverterParameter in the converter binding
2. As the Separator property on the converter

Note that the ConverterParameter option will take precedence over the Separator property.

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

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 ListToStringConverter

The ListToStringConverter 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.ListToStringConverterPage">

    <ContentPage.Resources>
        <ResourceDictionary>
            <toolkit:ListToStringConverter x:Key="ListToStringConverter" Separator="," />
        </ResourceDictionary>
    </ContentPage.Resources>

    <Label Text="{Binding MyListValue, Converter={StaticResource ListToStringConverter}}" />

</ContentPage>

C#

The ListToStringConverter can be used as follows in C#:

class ListToStringConverterPage : ContentPage
{
    public ListToStringConverterPage()
    {
        var label = new Label();

		label.SetBinding(
			Label.TextProperty,
			new Binding(
				nameof(ViewModels.MyListValue),
				converter: new ListToStringConverter() { Separator = "," }));

		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 ListToStringConverterPage : ContentPage
{
    public ListToStringConverterPage()
    {
        Content = new Label()
            .Bind(
                Label.TextProperty,
                static (ViewModel vm) => vm.MyListValue,
                converter: new ListToStringConverter(),
                converterParameter: ",");
    }
}

Properties

Property	Type	Description
Separator	string	The value that separates each item in the collection. This value is superseded by the ConverterParameter, if provided. If ConverterParameter is null, this Separator property will be used.

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 ListToStringConverter over on the .NET MAUI Community Toolkit GitHub repository.