How to use a custom font icon for header in .NET MAUI Expander (SfExpander)?

You can customize the expander header icon with font icons in .NET MAUI Expander. Please follow the steps below to use the font icons in the Expander Header element.

Step 1: Place the .ttf file in the project and set the Build action to MauiFont.

Step 2: Create a ResourceDictionary to define the custom font as a StaticResource.

<ContentPage.Resources>
    <ResourceDictionary>
        <OnPlatform x:TypeArguments="x:String" x:Key="ExpanderIcon">
            <On Platform="Android" Value="ExpanderIcons.ttf#ExpanderIcons" />
            <On Platform="WinUI" Value="ExpanderIcons.ttf#ExpanderIcons" />
            <On Platform="iOS" Value="ExpanderIcons" />
            <On Platform="MacCatalyst" Value="ExpanderIcons"/>
        </OnPlatform>
    </ResourceDictionary>
    <local:ExpanderIconConverter x:Key="ExpanderIconConverter"/>
</ContentPage.Resources>

Step 3: Bind the FontFamily for Label using resource key. Use converter to display icons based on IsExpanded. Set HeaderIconPosition as None to hide the default Header icon.

<ContentPage.Content>
    <ScrollView BackgroundColor="#EDF2F5">
        <StackLayout>
            <syncfusion:SfExpander x:Name="expander1" HeaderIconPosition="None">
                <syncfusion:SfExpander.Header>
                    <Grid HeightRequest="50">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="70"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <Label HorizontalOptions="Center" VerticalOptions="Center"
                         FontFamily="{StaticResource ExpanderIcon}"
                         Text="{Binding Path=IsExpanded,Source={x:Reference expander1}, Converter={StaticResource ExpanderIconConverter}}"/>
                        <Label Text="Veg Pizza" Grid.Column="1" TextColor="#495F6E"  VerticalTextAlignment="Center" />
                    </Grid>
                </syncfusion:SfExpander.Header>
                <syncfusion:SfExpander.Content>
                    <Grid Padding="10" BackgroundColor="#FFFFFF">
                        <Label BackgroundColor="#FFFFFF" HeightRequest="60" Text="Veg pizza is prepared with the items that meet vegetarian standards by not including any meat or animal tissue products." TextColor="#303030" VerticalTextAlignment="Center"/>
                    </Grid>
                </syncfusion:SfExpander.Content>
            </syncfusion:SfExpander>

            <syncfusion:SfExpander x:Name="expander2" HeaderIconPosition="None">
                <syncfusion:SfExpander.Header>
                    <Grid HeightRequest="50">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="70"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <Label HorizontalOptions="Center" VerticalOptions="Center"
                            FontFamily="{StaticResource ExpanderIcon}"
                            Text="{Binding Path=IsExpanded,Source={x:Reference expander2}, Converter={StaticResource ExpanderIconConverter}, ConverterParameter={x:Static Device.RuntimePlatform}}"/>
                        <Label Text="Non-veg Pizza" Grid.Column="1" TextColor="#495F6E"  VerticalTextAlignment="Center" />
                    </Grid>
                </syncfusion:SfExpander.Header>
                <syncfusion:SfExpander.Content>
                    <Grid Padding="10" BackgroundColor="#FFFFFF">
                        <Label Text="Non-veg pizza is prepared by including the meat and animal tissue products." HeightRequest="50" TextColor="#303030" VerticalTextAlignment="Center"/>
                    </Grid>
                </syncfusion:SfExpander.Content>
            </syncfusion:SfExpander>
        </StackLayout>
    </ScrollView>
</ContentPage.Content>

Step 4: Converter to display icon.

public class ExpanderIconConverter : IValueConverter
{
   public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
   {
       if ((bool)value)
       {
           return "\ue700";              
       }
       else
       {             
           return "\ue701";               
       }
   }

   public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
   {
       throw new NotImplementedException();
   }
}

Output

Download the complete sample on GitHub

Conclusion
I hope you enjoyed learning how to use a custom font icon for a header in .NET MAUI (SfExpander).
You can refer to our .NET MAUI Expander feature tour page to know about its other groundbreaking feature representations and documentation, and how to quickly get started with configuration specifications. Explore our .NET MAUI Expander example to understand how to create and manipulate data.
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