IsInRangeConverter

Article
03/01/2023

The IsInRangeConverter is a one-way converter that takes an incoming value implementing IComparable, and returns the result of the value being between the minimum and maximum values. The result will default to a bool if no objects were specified through the TrueObject and/or FalseObject properties. If values are assigned to the TrueObject and FalseObject properties, the IsInRangeConverter returns the respective object assigned.

Note

Note that the either both the TrueObject and FalseObject should have a value defined or neither should.

The ConvertBack method is not supported.

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 IsInRangeConverter

The IsInRangeConverter 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.IsInRangeConverterPage">
        <ResourceDictionary>
            <x:String x:Key="MinValue">Hello</x:String>
            <x:String x:Key="MaxValue">World</x:String>
            <Color x:Key="TrueColor">Green</Color>
            <Color x:Key="FalseColor">Red</Color>
        </ResourceDictionary>

    <Label BackgroundColor="{Binding MyValue, Converter={toolkit:IsInRangeConverter TrueObject={StaticResource TrueColor}, FalseObject={StaticResource FalseColor}, MinValue={StaticResource MinValue}, MaxValue={StaticResource MaxValue}}}" Text="The background of this label will be green if MyValue is between 'Hello' and 'World', otherwise red." />

</ContentPage>

C#

The IsInRangeConverter can be used as follows in C#:


class IsInRangeConverterPage : ContentPage
{
    public IsInRangeConverterPage()
    {
        Content = new Label()
            .Text("The background of this label will be green if MyValue is between 'Hello' and 'World', otherwise red.")
            .Bind(
                Label.BackgroundColorProperty,
                static (ViewModel vm) => vm.MyValue,
                converter: new IsInRangeConverter
                {
                        TrueObject = Colors.Green,
                        FalseObject = Colors.Red,
                        MinValue = "Hello",
                        MaxValue = "World"
                });
    }
}

Properties

Property	Type	Description
MinValue	`IComparable`	The minimum value for the compare range.
MaxValue	`IComparable`	The maximum value for the compare range.
FalseObject	`object`	The result to return if the comparison results in a `false` comparison.
TrueObject	`object`	The result to return if the comparison results in a `true` comparison.

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

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