DoubleToIntConverter

Article
03/01/2023

The DoubleToIntConverter is a converter that allows users to convert an incoming double value to an int and vice-versa. Optionally the user can provide a multiplier to the conversion through the Ratio property.

The Convert method returns the supplied value converted to an int and multiplied by a ratio.

The ConvertBack method returns the supplied value converted to a double and divided by a ratio.

Note

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

as the ConverterParameter in the converter binding,
as the Ratio property on the converter.

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

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 DoubleToIntConverter

The DoubleToIntConverter 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.DoubleToIntConverterPage">

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

    <Label Text="{Binding MyValue, Converter={StaticResource DoubleToIntConverter}}" />

</ContentPage>

C#

The DoubleToIntConverter can be used as follows in C#:

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

        label.SetBinding(
            Label.TextProperty,
            new Binding(
                static (ViewModel vm) => vm.MyValue,
                converter: new DoubleToIntConverter()));

        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 DoubleToIntConverterPage : ContentPage
{
    public DoubleToIntConverterPage()
    {
        Content = new Label()
            .Bind(
                Label.TextProperty,
                static (ViewModel vm) => vm.MyValue,
                converter: new DoubleToIntConverter());
    }
}

Properties

Property	Type	Description
Ratio	`int`	The multiplier to apply during the conversion.

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

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