Maui pinch recogniser not working

Question

Hi All  

why this pinch gesture not work

I am trying to change font size
according to pinch event e.Scale

thanks for any help

             <ScrollView.GestureRecognizers>  
                   <PinchGestureRecognizer PinchUpdated="OnPinchUpdated" />  
             </ScrollView.GestureRecognizers>  




namespace MyFilePickerApp  
{  
  public partial class MainPage : ContentPage  
  {  
    string AppDataDirectoryPath = "";  
    int nnFontSize = 16;  
    double currentScale = 1;  
    int currentFont = 16;  
  
    public MainPage()  
    {  
      InitializeComponent();  
    }  
  
  
    //-----------------------------------------------------------------------------  
  
    void OnPinchUpdated(object sender, PinchGestureUpdatedEventArgs e)  
    {  
       // Handle the pinch  
       if(e.Scale > currentScale)  
       {  
          currentScale = e.Scale;  
          currentFont += 1;  
          OpenFileLabel.FontSize = currentFont;  
       }  
       else if(e.Scale < currentScale)  
       {  
          currentScale = e.Scale;  
          currentFont -= 1;  
          OpenFileLabel.FontSize = currentFont;  
       }  
    }  
  
    //-----------------------------------------------------------------------------  
  
  
  
  
  
  
<?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"  
             x:Class="MyFilePickerApp.MainPage"  
             xmlns:mct="clr-namespace:CommunityToolkit.Maui.Behaviors;assembly=CommunityToolkit.Maui"  
             FlowDirection="LeftToRight" BackgroundColor="#107e71" >  
  
    <Page.Behaviors>  
        <mct:StatusBarBehavior StatusBarColor="#107e71" StatusBarStyle="LightContent" />  
    </Page.Behaviors>  
   
    <Grid RowDefinitions="10,50,50,*,50,10" ColumnDefinitions="*"  
            BackgroundColor="#ECE5DD" Margin="10" >  
  
            <Label x:Name="SaveFileLabel" FlowDirection="LeftToRight" Grid.Row="1" Grid.Column="0"  
                Text="Save My File"  
                FontSize="18"  
                HorizontalOptions="Center" />  
  
            <Grid Grid.Row="2" ColumnDefinitions="2*, 4*, 4* ,4* ,2*" Padding="0,10" >  
                <Button x:Name="SaveFileBtn" Text="Save a File" BackgroundColor="BlueViolet"  
                    HorizontalOptions="Fill" VerticalOptions="Center"  
                    CornerRadius="20" BorderColor="Black" TextColor="White"  
                    BorderWidth="1"  
                    Clicked="OnSaveFileClicked" FontAttributes="Bold"  
                    Padding="0,0,0,0" Grid.Column="1" />  
  
                <Button x:Name="OpenFileBtn" Text="Pick a File" BackgroundColor="BlueViolet"  
                    HorizontalOptions="Fill" VerticalOptions="Center"  
                    CornerRadius="20" BorderColor="Black" TextColor="White"  
                    BorderWidth="1"  
                    Clicked="OnOpenFileClicked" FontAttributes="Bold"  
                    Padding="0,0,0,0" Grid.Column="3" />  
            </Grid>  
  
            <ScrollView x:Name="scroll" Orientation="Vertical" Grid.Row="3" Grid.Column="0"  
                        VerticalScrollBarVisibility="Always" >  
                <ScrollView.GestureRecognizers>  
                      <PinchGestureRecognizer PinchUpdated="OnPinchUpdated" />  
                </ScrollView.GestureRecognizers>  
  
            <ScrollView Orientation="Horizontal" HorizontalScrollBarVisibility="Always" >  
  
                <Label x:Name="OpenFileLabel" FlowDirection="LeftToRight"  
                    Text="Open By File Picker"  
                    FontSize="16"  
                    HorizontalOptions="Start" >  
                </Label>  
                </ScrollView>  
            </ScrollView>  
            
            <Grid Grid.Row="4" ColumnDefinitions="2*, 4*, 4* ,4* ,2*" Padding="0,10" >  
                <Button x:Name="PreviousSize" Text="Size  -" BackgroundColor="BlueViolet"  
                    HorizontalOptions="Fill" VerticalOptions="Center"  
                    CornerRadius="20" BorderColor="Black" TextColor="White"  
                    BorderWidth="1"  
                    Clicked="PreviousSize_Clicked" FontAttributes="Bold"  
                    Padding="0,0,0,0" Grid.Column="1" />  
  
                <Label x:Name="fontSize"  Text="Font 16" FontAttributes="Bold"  
                    HorizontalOptions="Center" VerticalOptions="Center"  
                    Grid.Column="2" />  
  
                <Button x:Name="NextSize" Text="Size  +" BackgroundColor="BlueViolet"  
                    HorizontalOptions="Fill" VerticalOptions="Center"  
                    CornerRadius="20" BorderColor="Black" TextColor="White"  
                    BorderWidth="1"  
                    Clicked="NextSize_Clicked" FontAttributes="Bold"  
                    Padding="0,0,0,0" Grid.Column="3" />  
            </Grid>  
       
   </Grid>  
  
</ContentPage>