Choice ObjectChoice = new Choice();
var content = await ObjectChoice .ShowAsync();

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <RadioButton Grid.Row="0" GroupName="one" Content="Yes" Checked="RadioButton_Checked" />
    <RadioButton Grid.Row="1" GroupName="one" Content="No" Checked="RadioButton_Checked_1" IsChecked="True"/>
</Grid>