Port Local Notification Sample to .NET 7 (#341)

* New Button Sample port

* Made a few changes on MainActivity.cs

* Removed autogenerated files and a modification on MainActivity.cs

* Added Metadata.xml file

* Added string interpolation on MainActivity.cs and updated the screenshot

* Added string interpolation

* New Local Notifications sample port from legacy

* Modified a comment and removed an extra line on MainActivity.cs

* Added spacing at line 76 on MainActivity.cs

* Added additional null check on SecondActivity.cs

* Addded PendingIntentFlags.Immutable for API 31+ when creating PendingIntent

* Delete Metadata.xml

* Update to latest Xamarin.AndroidX.AppCompat

* Better use of C# features/null check

* Fix project namespaces

* Request appropriate permissions

* Update to .NET 7

Co-authored-by: Jonathan Peppers <jonathan.peppers@microsoft.com>

LocalNotifications/LocalNotifications.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.3.32519.111
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LocalNotifications", "LocalNotifications\LocalNotifications.csproj", "{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}.Debug|Any CPU.Deploy.0 = Debug|Any CPU
+		{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}.Release|Any CPU.Build.0 = Release|Any CPU
+		{4B2A0076-A973-4AC3-B762-4B889BEFC9C2}.Release|Any CPU.Deploy.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {5AFA1196-F555-4E40-8873-088B8649B8A4}
+	EndGlobalSection
+EndGlobal

LocalNotifications/LocalNotifications/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+  <application android:allowBackup="true" android:theme="@style/AppTheme" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true">
+  </application>
+  <uses-permission android:name="android.permission.INTERNET" />
+  <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+</manifest>

LocalNotifications/LocalNotifications/LocalNotifications.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net7.0-android</TargetFramework>
+    <SupportedOSPlatformVersion>23</SupportedOSPlatformVersion>
+    <OutputType>Exe</OutputType>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <ApplicationId>com.companyname.LocalNotifications</ApplicationId>
+    <ApplicationVersion>1</ApplicationVersion>
+    <ApplicationDisplayVersion>1.0</ApplicationDisplayVersion>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Xamarin.AndroidX.AppCompat" Version="1.5.1.1" />
+  </ItemGroup>
+</Project>

LocalNotifications/LocalNotifications/MainActivity.cs

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+using Android.Content;
+using Android.Content.PM;
+using Android.Content.Res;
+using Android.Runtime;
+using AndroidX.AppCompat.App;
+using AndroidX.Core.App;
+using Java.Lang;
+using TaskStackBuilder = AndroidX.Core.App.TaskStackBuilder;
+
+namespace LocalNotifications;
+
+[Activity (Label = "Notifications", MainLauncher = true, Icon = "@drawable/Icon")]
+public class MainActivity : AppCompatActivity
+{
+    const string PERMISSION = "android.permission.POST_NOTIFICATIONS";
+    const int REQUEST_CODE = 1;
+    /// <summary>
+    /// Unique ID for our notification
+    /// </summary>
+    const int NOTIFICATION_ID = 1000;
+    const string CHANNEL_ID = "location_notification";
+    public const string COUNT_KEY = "count";
+
+    // Number of times the button is tapped (starts with first tap):
+    int count = 1;
+
+    protected override void OnCreate (Bundle? bundle)
+    {
+        base.OnCreate (bundle);
+        SetContentView (Resource.Layout.Main);
+
+        // Display the "Hello World, Click Me!" button and register its event handler:
+        var button = RequireViewById<Button> (Resource.Id.MyButton);
+        button.Click += (sender, e) =>
+        {
+            if (CheckSelfPermission(PERMISSION) == Permission.Denied)
+            {
+                ActivityCompat.RequestPermissions(this, new[] { PERMISSION }, REQUEST_CODE);
+            }
+            else
+            {
+                CreateNotification();
+            }
+        };
+
+        CreateNotificationChannel();
+    }
+
+    public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
+    {
+        if (requestCode == REQUEST_CODE)
+        {
+            if (permissions.Length > 0 && permissions[0] == PERMISSION &&
+                grantResults.Length > 0 && grantResults[0] == Permission.Granted)
+            {
+                CreateNotification();
+            }
+            else
+            {
+                Toast.MakeText(this, "Unable to request permissions!", ToastLength.Long)!.Show();
+            }
+        }
+    }
+
+    void CreateNotification()
+    {
+        // Pass the current button press count value to the next activity:
+        var valuesForActivity = new Bundle();
+        valuesForActivity.PutInt(COUNT_KEY, count);
+
+        // When the user clicks the notification, SecondActivity will start up.
+        var resultIntent = new Intent(this, typeof(SecondActivity));
+
+        // Pass some values to SecondActivity:
+        resultIntent.PutExtras(valuesForActivity);
+
+        // Construct a back stack for cross-task navigation:
+        var stackBuilder = TaskStackBuilder.Create(this);
+        ArgumentNullException.ThrowIfNull(stackBuilder);
+        stackBuilder.AddParentStack(Class.FromType(typeof(SecondActivity)));
+        stackBuilder.AddNextIntent(resultIntent);
+
+        // Create the PendingIntent with the back stack:            
+        var resultPendingIntent = stackBuilder.GetPendingIntent(0, (int)PendingIntentFlags.Immutable);
+
+        // Build the notification:
+        var builder = new NotificationCompat.Builder(this, CHANNEL_ID)
+                        .SetAutoCancel(true) // Dismiss the notification from the notification area when the user clicks on it
+                        .SetContentIntent(resultPendingIntent) // Start up this activity when the user clicks the intent.
+                        .SetContentTitle("Button Clicked") // Set the title
+                        .SetNumber(count) // Display the count in the Content Info
+                        .SetSmallIcon(Resource.Mipmap.ic_stat_button_click) // This is the icon to display
+                        .SetContentText($"The button has been clicked {count} times."); // the message to display.
+
+        // Finally, publish the notification:
+        var notificationManager = NotificationManagerCompat.From(this);
+        if (notificationManager.AreNotificationsEnabled())
+        {
+            notificationManager.Notify(NOTIFICATION_ID, builder.Build());
+        }
+        else
+        {
+            Toast.MakeText(this, "Notifications are not enabled!", ToastLength.Long)!.Show();
+        }
+
+        // Increment the button press count:
+        count++;
+    }
+
+    void CreateNotificationChannel ()
+    {
+        ArgumentNullException.ThrowIfNull (Resources);
+
+        // Creating a NotificationChannel is only needed in API 26+
+        if (OperatingSystem.IsAndroidVersionAtLeast (26))
+        {
+            var name = Resources.GetString (Resource.String.channel_name);
+            var description = GetString (Resource.String.channel_description);
+            var channel = new NotificationChannel (CHANNEL_ID, name, NotificationImportance.Default)
+            {
+                Description = description
+            };
+
+            if (GetSystemService(NotificationService) is NotificationManager manager)
+            {
+                manager.CreateNotificationChannel(channel);
+            }
+        }
+    }
+}

LocalNotifications/LocalNotifications/Resources/AboutResources.txt

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+Images, layout descriptions, binary blobs and string dictionaries can be included 
+in your application as resource files.  Various Android APIs are designed to 
+operate on the resource IDs instead of dealing with images, strings or binary blobs 
+directly.
+
+For example, a sample Android app that contains a user interface layout (main.xml),
+an internationalization string table (strings.xml) and some icons (drawable-XXX/icon.png) 
+would keep its resources in the "Resources" directory of the application:
+
+Resources/
+    drawable/
+        icon.png
+
+    layout/
+        main.xml
+
+    values/
+        strings.xml
+
+In order to get the build system to recognize Android resources, set the build action to
+"AndroidResource".  The native Android APIs do not operate directly with filenames, but 
+instead operate on resource IDs.  When you compile an Android application that uses resources, 
+the build system will package the resources for distribution and generate a class called "Resource" 
+(this is an Android convention) that contains the tokens for each one of the resources 
+included. For example, for the above Resources layout, this is what the Resource class would expose:
+
+public class Resource {
+    public class Drawable {
+        public const int icon = 0x123;
+    }
+
+    public class Layout {
+        public const int main = 0x456;
+    }
+
+    public class Strings {
+        public const int first_string = 0xabc;
+        public const int second_string = 0xbcd;
+    }
+}
+
+You would then use Resource.Drawable.icon to reference the drawable/icon.png file, or 
+Resource.Layout.main to reference the layout/main.xml file, or Resource.Strings.first_string 
+to reference the first string in the dictionary file values/strings.xml.

LocalNotifications/LocalNotifications/Resources/layout/Main.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent">
+    <Button
+        android:id="@+id/MyButton"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/Hello" />
+</LinearLayout>

LocalNotifications/LocalNotifications/Resources/layout/Second.axml

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+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:minWidth="25px"
+    android:minHeight="25px">
+    <TextView
+        android:text=""
+        android:textAppearance="?android:attr/textAppearanceLarge"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:id="@+id/textView1" />
+</LinearLayout>

LocalNotifications/LocalNotifications/Resources/mipmap-anydpi-v26/ic_launcher.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background"/>
+    <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+</adaptive-icon>

LocalNotifications/LocalNotifications/Resources/mipmap-anydpi-v26/ic_launcher_round.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background"/>
+    <foreground android:drawable="@mipmap/ic_launcher_foreground"/>
+</adaptive-icon>

LocalNotifications/LocalNotifications/Resources/values/colours.xml

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+<?xml version="1.0" encoding="utf-8"?>
+
+<resources>
+	<color name="colorPrimary">#3F51B5</color>
+	<color name="colorPrimaryDark">#303F9F</color>
+	<color name="colorAccent">#FF4081</color>
+	<color name="ic_launcher_background">#FFFFFF</color>
+</resources>

LocalNotifications/LocalNotifications/Resources/values/strings.xml

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+<resources>
+    <string name="app_name">LocalNotifications</string>
+	<string name="Hello">Hello World, Click Me!</string>
+
+	<string name="channel_name">Local Notifications</string>
+	<string name="channel_description">The count from MainActivity.</string>
+</resources>

LocalNotifications/LocalNotifications/Resources/values/styles.xml

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+<?xml version="1.0" encoding="utf-8"?>
+
+<resources>
+
+  <!-- Base application theme. -->
+  <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
+    <!-- Customize your theme here. -->
+    <item name="colorPrimary">@color/colorPrimary</item>
+    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
+    <item name="colorAccent">@color/colorAccent</item>
+  </style>
+
+</resources>

LocalNotifications/LocalNotifications/SecondActivity.cs

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+using AndroidX.AppCompat.App;
+
+namespace LocalNotifications;
+
+[Activity (Label = "Second Activity")]
+public class SecondActivity : AppCompatActivity
+{
+    protected override void OnCreate (Bundle? bundle)
+    {
+        base.OnCreate (bundle);
+
+        // Get the count value passed to us from MainActivity:
+        var count = Intent?.Extras?.GetInt (MainActivity.COUNT_KEY, -1);
+
+        // No count was passed? Then just return.
+        if (count is not null && count <= 0)
+            return;
+
+        // Display the count sent from the first activity:
+        SetContentView (Resource.Layout.Second);
+        var txtView = RequireViewById<TextView> (Resource.Id.textView1);
+        txtView.Text = $"You clicked the button {count} times in the previous activity.";
+    }
+}

LocalNotifications/README.md

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+---
+name: Xamarin.Android - Android Local Notifications Sample
+description: This sample app accompanies the article Using Local Notifications in Xamarin.Android.
+page_type: sample
+languages:
+- csharp
+products:
+- xamarin
+urlFragment: localnotifications
+---
+# Android Local Notifications Sample
+
+This sample app accompanies the article,
+[Walkthrough - Using Local Notifications in Xamarin.Android](https://docs.microsoft.com/xamarin/android/app-fundamentals/notifications/local-notifications-walkthrough).
+
+![Android app screenshot](Screenshots/screenshot-1.png)
+
+When you tap the button displayed in the MainActivity screen, a
+notification is created. When you tap the notification, it
+takes you to a SecondActivity screen.