test/CircleViewerMaui/MainPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:pdfViewer="http://schemas.syncfusion.com/maui"
             x:Class="CircleViewerMaui.MainPage">

    <ContentPage.Content>
        <Grid x:Name="mainGrid">
            <Grid.RowDefinitions>
                <RowDefinition Height="50" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <AbsoluteLayout>
                <Grid x:Name="toolbar" Grid.Row="0" BackgroundColor="#E9E9E9" HorizontalOptions="Fill" VerticalOptions="Fill">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="1*" />
                        <ColumnDefinition Width="0.4*" />
                        <ColumnDefinition Width="1*" />
                        <ColumnDefinition Width="1*" />
                        <ColumnDefinition Width="1*" />
                    </Grid.ColumnDefinitions>
                    <Button x:Name="openButton"  Grid.Column="3" BackgroundColor="Yellow" TextColor="Black" Text="Open" HorizontalOptions="Center" VerticalOptions="Center" Clicked="onOpenClicked"/>
                </Grid>
            </AbsoluteLayout>
            <Grid x:Name="pdfViewGrid" Grid.Row="1">
                <pdfViewer:SfPdfViewer x:Name="PdfViewer" VerticalOptions="Fill">
                </pdfViewer:SfPdfViewer>
            </Grid>
        </Grid>
    </ContentPage.Content>
</ContentPage>