C# How to Use Notification Listener

Question

I'm trying to code a form for show notifications in my form from Notification Center but there is some error I did not understand errors.

Errors:

*Severity Code Description Project File Line Suppression State
Error CS4036 'IAsyncOperation<UserNotificationListenerAccessStatus>' does not contain a definition for 'GetAwaiter' and no extension method 'GetAwaiter' accepting a first argument of type 'IAsyncOperation<UserNotificationListenerAccessStatus>' could be found (are you missing a using directive for 'System'?) WindowsFormsApp7 C:\Users\stock\source\repos\WindowsFormsApp7\WindowsFormsApp7\Class1.cs 12 Active
*
*Severity Code Description Project File Line Suppression State
Error CS1061 'UserNotificationListener' does not contain a definition for 'GetNotifications' and no accessible extension method 'GetNotifications' accepting a first argument of type 'UserNotificationListener' could be found (are you missing a using directive or an assembly reference?) WindowsFormsApp7 C:\Users\stock\source\repos\WindowsFormsApp7\WindowsFormsApp7\Class1.cs 17 Active
*
*Severity Code Description Project File Line Suppression State
Error CS1061 'UserNotificationChangedEventArgs' does not contain a definition for 'Notification' and no accessible extension method 'Notification' accepting a first argument of type 'UserNotificationChangedEventArgs' could be found (are you missing a using directive or an assembly reference?) WindowsFormsApp7 C:\Users\stock\source\repos\WindowsFormsApp7\WindowsFormsApp7\Class1.cs 33 Active
*
*Severity Code Description Project File Line Suppression State
Error CS4036 'IAsyncOperation<UserNotificationListenerAccessStatus>' does not contain a definition for 'GetAwaiter' and no extension method 'GetAwaiter' accepting a first argument of type 'IAsyncOperation<UserNotificationListenerAccessStatus>' could be found (are you missing a using directive for 'System'?) WindowsFormsApp7 C:\Users\stock\source\repos\WindowsFormsApp7\WindowsFormsApp7\Form2.cs 29 Active
*
*Severity Code Description Project File Line Suppression State
Error CS1061 'UserNotificationListener' does not contain a definition for 'GetNotifications' and no accessible extension method 'GetNotifications' accepting a first argument of type 'UserNotificationListener' could be found (are you missing a using directive or an assembly reference?) WindowsFormsApp7 C:\Users\stock\source\repos\WindowsFormsApp7\WindowsFormsApp7\Form2.cs 34 Active
*
*Severity Code Description Project File Line Suppression State
Error CS1061 'UserNotificationChangedEventArgs' does not contain a definition for 'Notification' and no accessible extension method 'Notification' accepting a first argument of type 'UserNotificationChangedEventArgs' could be found (are you missing a using directive or an assembly reference?) WindowsFormsApp7 C:\Users\stock\source\repos\WindowsFormsApp7\WindowsFormsApp7\Form2.cs 50 Active
*

using System;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Data;  
using System.Drawing;  
using System.Linq;  
using System.Runtime.CompilerServices;  
using System.Text;  
using System.Threading.Tasks;  
using System.Windows.Forms;  
using Windows.UI.Notifications;  
using Windows.UI.Notifications.Management;  
  
namespace WindowsFormsApp7  
{  
    public partial class Form2 : Form  
    {  
        public Form2()  
        {  
            InitializeComponent();  
        }  
  
        public async Task StartListeningAsync()  
        {  
            // Request access to the user's notifications  
            var accessStatus = await UserNotificationListener.Current.RequestAccessAsync();  
  
            if (accessStatus == UserNotificationListenerAccessStatus.Allowed)  
            {  
                // Get the user's notifications  
                var notifications = UserNotificationListener.Current.GetNotifications(NotificationKinds.Toast);  
  
                foreach (var notification in notifications)  
                {  
                    // Process the notification  
                    ProcessNotification(notification);  
                }  
  
                // Register for notifications when they are updated  
                UserNotificationListener.Current.NotificationChanged += OnNotificationChanged;  
            }  
        }  
  
        private void OnNotificationChanged(UserNotificationListener sender, UserNotificationChangedEventArgs args)  
        {  
            // Process the updated notification  
            ProcessNotification(args.Notification);  
        }  
  
        private void ProcessNotification(UserNotification notification)  
        {  
            // Do something with the notification  
        }  
    }  
}  
  

Answer 1

Same question as C# Get Current Notification Details | UserNotification
I posted the 2 DLLs to be referenced and it works fine for me with a .NET Framework project

Answer 2

"C:\Program Files (x86)\Windows Kits\10\UnionMetadata[version]\Windows.winmd"
and
"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETCore\v4.5\System.Runtime.WindowsRuntime.dll"

There are no dlls like they. How to donwload it? I'm on my school computer.

And there was an error says "You have to add a package for it." But I never understood it.

Answer 3

I did and everything working fine now. I removed codes which one using AppInfo as you said and It's working fine now.