StringToListConverter
The StringToListConverter
is a one way converter that returns a set of substrings by splitting the input string based on one or more separators.
The Convert
method returns a set of substrings by splitting the input string based on one or more separators.
Note
Note that the separators can be supplied in the following order of precedence:
- as the
ConverterParameter
in the converter binding; this supersedes bothSeparators
andSeparator
properties - as the
Separators
property on the converter; this supersedes theSeparator
property - as the
Separator
property on the converter.
The ConvertBack
method is not supported. For the opposite behavior see the ListToStringConverter
.
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 StringToListConverter
The StringToListConverter
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.StringToListConverterPage">
<ContentPage.Resources>
<ResourceDictionary>
<toolkit:StringToListConverter x:Key="StringToListConverter" SplitOptions="RemoveEmptyEntries">
<toolkit:StringToListConverter.Separators>
<x:String>,</x:String>
<x:String>.</x:String>
<x:String>;</x:String>
</toolkit:StringToListConverter.Separators>
</toolkit:StringToListConverter>
</ResourceDictionary>
</ContentPage.Resources>
<VerticalStackLayout>
<Entry
Placeholder="Enter some text separated by ',' or '.' or ';'"
Text="{Binding MyValue}" />
<CollectionView ItemsSource="{Binding MyValue, Converter={StaticResource StringToListConverter}}">
<CollectionView.ItemTemplate>
<DataTemplate>
<Label Text="{Binding .}" />
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
</VerticalStackLayout>
</ContentPage>
C#
The StringToListConverter
can be used as follows in C#:
class StringToListConverterPage : ContentPage
{
public StringToListConverterPage()
{
var entry = new Entry { Placeholder = "Enter some text separated by ',' or '.' or ';'" };
entry.SetBinding(Entry.TextProperty, new Binding(nameof(ViewModel.MyValue)));
var stringToListConverter = new StringToListConverter
{
SplitOptions = System.StringSplitOptions.RemoveEmptyEntries,
Separators = new [] { ",", ".", ";" }
};
var collectionView = new CollectionView
{
ItemTemplate = new DataTemplate(() =>
{
var itemLabel = new Label();
itemLabel.SetBinding(Label.TextProperty, path: ".");
return itemLabel;
})
};
collectionView.SetBinding(
CollectionView.ItemsSourceProperty,
new Binding(
nameof(ViewModel.MyValue),
converter: stringToListConverter));
Content = new VerticalStackLayout
{
Children =
{
entry,
collectionView
}
};
}
}
C# Markup
Our CommunityToolkit.Maui.Markup
package provides a much more concise way to use this converter in C#.
using CommunityToolkit.Maui.Markup;
class StringToListConverterPage : ContentPage
{
public StringToListConverterPage()
{
Content = new VerticalStackLayout
{
Children =
{
new Entry { Placeholder = "Enter some text separated by ',' or '.' or ';'" }
.Bind(
Entry.TextProperty,
static (ViewModel vm) => vm.MyValue),
new CollectionView
{
ItemTemplate = new DataTemplate(() => new Label().Bind(Label.TextProperty, path: Binding.SelfPath))
}.Bind(
CollectionView.ItemsSourceProperty,
static (ViewModel vm) => vm.MyValue,
converter: new StringToListConverter
{
SplitOptions = System.StringSplitOptions.RemoveEmptyEntries,
Separators = new [] { ",", ".", ";" }
})
}
};
}
}
Properties
Property | Type | Description |
---|---|---|
Separator | string |
The string that delimits the substrings in the incoming string. This value is superseded by both ConverterParameter and Separators . If ConverterParameter is null and Separators is empty, this value will be used. |
Separators | IList<string> |
The strings that delimits the substrings in the incoming string. This value is superseded by ConverterParameter . If ConverterParameter is null this value will be used. |
SplitOptions | StringSplitOptions |
A bitwise combination of the enumeration values that specifies whether to trim substrings and include empty substrings. |
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 StringToListConverter
over on the .NET MAUI Community Toolkit GitHub repository.
.NET MAUI Community Toolkit