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Mobile Tutorial: Using Notifications (iOS and Android)

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Go Up to Mobile Tutorials: Mobile Application Development (iOS and Android)


This tutorial describes the basic steps to use notifications on your mobile device; for further details, see using notifications.

Three Basic Notification or Alert Styles

When users set notifications for apps on their mobile devices, notifications can be delivered from apps in the three basic styles shown here. The banner appears briefly, but the alert dialog box requires dismissal by the user.

Notification Banner on Mobile Devices

iOS

IOSNotificationBanner.PNG

Android

Android Notification.png


Alert Dialogs: iOS Badge Number and Android Notification Number

iOS Badge Number
iPad

Android Notification Number
Android

Notification Center on Mobile Devices

The following images show the notification center on an iPad (Notification Center) and Android (notification drawer), where the user can pull down the list of all recent notifications.

iOS

IOSNotificationCenter.PNG

Android

Android Notification Center.png

Access the Notification Service

RAD Studio provides the TNotificationCenter component that allows you to easily access the Notification Service.

To access the notification service, do the following:

  1. Create a new mobile application:
  2. Select the TNotificationCenter component in the Tool Palette, and drop it on the Form Designer.
  3. Check that the following unit has been automatically added to the project:
    • For Delphi applications, add the following unit to the uses clause if it is not present:
    uses
      System.Notification;
    • For C++ applications, add the following include operator to the project header file (.h file):
    #include <System.Notification.hpp>

The System.Notification.TNotificationCenter.CreateNotification method allows you to create an instance of the TNotification class object.

Add FMLocalNotificationPermission (iOS)

In order to use notifications on iOS 8+ devices, you need to ensure that the FMLocalNotificationPermission Key/Value pair is enabled on the Version Info page of Project Options.

  1. Choose Project > Options > Version Info.
  2. In the Target field, select Debug configuration - iOS device - 32-bit platform.
  3. Set the Value field for FMLocalNotificationPermission to true.
    The FMLocalNotificationPermission setting enables local notifications on iOS 8+ devices:
FMLocalNotificationPermission.png

Set the Icon Badge Number and Notification Number from Code

TNotification.Number defines the Icon Badge Number (for iOS devices) and the notification number (for Android devices).

To set the iOS icon badge number (for Delphi or C++) or the Android notification number (only for Delphi apps), you need to implement the corresponding method.

  1. Drop a TButton to the form.
  2. In the Object Inspector, change the Name property to SetNumber.
  3. Create the OnClick event of the SetNumber button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the SetNumber button by adding the following code:
    • For Delphi:
    procedure TForm1.SetNumberClick(Sender: TObject);
    var
      MyNotification: TNotification;
    begin
      // Create an instance of TNotification
      MyNotification := NotificationCenter1.CreateNotification;
      try
          // --- your code goes here ---
          // Set the icon or notification number
          MyNotification.Number :=18;
          // Set the alert message
          MyNotification.AlertBody := 'Delphi for your mobile device is here!';
          // Note: You must send the notification to the notification center for the Icon Badge Number to be displayed.
          NotificationCenter1.PresentNotification(MyNotification);
      finally
        MyNotification.DisposeOf;
      end;
    end;
    • For C++:
    void __fastcall TForm1::SetNumberClick(TObject *Sender)
    {
            if (NotificationCenter1->Supported()) {
                    TNotification *myNotification = NotificationCenter1->CreateNotification();
                    __try {
                            myNotification->Number = 18;
                            myNotification->AlertBody = "C++ for your mobile device is here!";
                            NotificationCenter1->PresentNotification(myNotification);
                    }
                    __finally {
                            myNotification->DisposeOf();
                    }
            }
     
    }

After running your application (press F9) and clicking the SetNumber button, you can see the following:

  • A badge on the application icon (on the iOS Home screen):
    IOSNotification.PNG

  • A number next to the notification message in the notification center (on Android):
    Android

Schedule Notification

You can also schedule Notification Messages using the ScheduleNotification method that the TNotificationCenter class inherits from TCustomNotificationCenter.

To show a Notification Message, you need to create an instance of the TNotification class, and then define the Name, AlertBody, and FireDate fields.

  1. Drop a new TButton to the form.
  2. In the Object Inspector, change the Name property to ScheduleNotification.
  3. Create the OnClick event of the ScheduleNotification button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the ScheduleNotification button by adding the following code:
    • For Delphi:
    procedure TForm1.ScheduleNotificationClick(Sender: TObject);
    var
      MyNotification: TNotification;
    begin
      MyNotification := NotificationCenter1.CreateNotification;
      try
        MyNotification.Name := 'MyNotification';
        MyNotification.AlertBody := 'Delphi for your mobile device is here!';
        // Fired in 10 seconds
        MyNotification.FireDate := Now + EncodeTime(0, 0, 10, 0);
        // Send notification to the notification center
        NotificationCenter1.ScheduleNotification(MyNotification);
      finally
        MyNotification.DisposeOf;
      end;
    end;
    • For C++:
    void __fastcall TForm1::ScheduleNotificationClick(TObject *Sender)
    {
            if (NotificationCenter1->Supported()) {
                    TNotification *myNotification = NotificationCenter1->CreateNotification();
                    __try {
                            myNotification->Name = "MyNotification";
                            myNotification->AlertBody = "C++ for your mobile device is here!";
                            // Fire in 10 seconds
                            myNotification->FireDate = Now() + EncodeTime(0, 0, 10, 0);
                            // Send notification to the notification center
                            NotificationCenter1->ScheduleNotification(myNotification);
                    }
                    __finally {
                            myNotification->DisposeOf();
                    }
     
            }
    }

After running your application (press F9) and clicking the ScheduleNotification button, you can see the Notification Message (AlertBody) at the top of your device Home Screen. For iOS devices, this message is similar to the following screen:

IOS7NotificationBanner.png

Repeat a Notification Message

You can also repeat a Notification Message using the RepeatInterval property of the TNotification object.

To repeat a Notification Message, you need to create an instance of the TNotification class, and then define the Name, AlertBody, and FireDate fields.

Also you need to use the ScheduleNotification method and set the RepeatInterval property. In the following code, the repeated interval is set to a minute.

  1. Drop a new TButton to the form.
  2. In the Object Inspector, change the Name property to RepeatedNotification.
  3. Create the OnClick event of the RepeatedNotification button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the RepeatedNotification button by adding the following code:
    • For Delphi:
    procedure TForm1.RepeatedNotificationClick(Sender: TObject);
    var
      MyNotification: TNotification;
    begin
      MyNotification := NotificationCenter1.CreateNotification;
      try
        MyNotification.Title := 'MyNotification';
        MyNotification.AlertBody := 'Repeating notification each minute!';
        //Fired in 10 seconds
        MyNotification.FireDate := Now + EncodeTime(0, 0, 10, 0);
        //Repeated each minute
        MyNotification.RepeatInterval := TRepeatInterval.Minute;
        // Send notification to the notification center
        NotificationCenter1.ScheduleNotification(MyNotification);
      finally
        MyNotification.Free;
      end;
    end;
    • For C++:
    void __fastcall TForm1::RepeatedNotificationClick(TObject *Sender) {
        if (NotificationCenter1->Supported()) {
            TNotification *myNotification =
                NotificationCenter1->CreateNotification();
            __try {
                myNotification->Name = "MyNotification";
                myNotification->AlertBody = "Repeating notification each minute!";
                // Fire in 10 seconds
                myNotification->FireDate = Now() + EncodeTime(0, 0, 10, 0);
                // Repeated each minute
                myNotification->RepeatInterval = TRepeatInterval::Minute;
                // Send notification to the notification center
                NotificationCenter1->ScheduleNotification(myNotification);
            }
            __finally {
                myNotification->Free();
            }
     
        }
     
    }

After running your application (press F9) and clicking the RepeatedNotification button, you can see the Notification Message (AlertBody) at the top of your device Home Screen. For iOS devices, this message is similar to the following screen:

IOS7RepeatedNotificationBannerCpp.png

Update or Cancel a Scheduled or Repeated Notification Message

Each Scheduled Notification Message is identified through the Name property of the TNotification object.

Note: For the iOS platform, CancelNotification and ScheduleNotification can cancel or update those notifications that have not been presented yet.

To update a scheduled notification, simply call the ScheduleNotification method again with an instance of TNotification that has the same name (Name property).

To cancel a scheduled notification, you can simply call the CancelNotification method with the identifier you used.

  1. Drop a new TButton to the form.
  2. In the Object Inspector, change the Name property to CancelNotification.
  3. Create the OnClick event of the CancelNotification button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the CancelNotification button by adding the following code:
    • For Delphi:
    procedure TForm1.CancelNotificationClick(Sender: TObject);
     
    begin
       NotificationCenter1.CancelNotification('MyNotification');
    end;
    • For C++:
      void __fastcall TForm1::CancelNotificationClick(TObject *Sender)
    {
       NotificationCenter1->CancelNotification("MyNotification");
    }

Present the Notification Message Immediately

You can also show the notification message immediately through the PresentNotification function.

To show a notification message, you need to create an instance of the TNotification class, and then define the Name and AlertBody fields.

  1. Drop a new TButton to the form.
  2. In the Object Inspector, change the Name property to PresentNotification.
  3. Create the OnClick event of the PresentNotification button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the PresentNotification button by adding the following code:
    • For Delphi:
    procedure TForm1.PresentNotificationClick(Sender: TObject);
    var
      MyNotification: TNotification;
    begin
      MyNotification := NotificationCenter1.CreateNotification;
      try
        MyNotification.Name := 'MyNotification';
        MyNotification.AlertBody := 'Delphi for your mobile device is here!';
        // Set Icon Badge Number (for iOS) or message number (for Android) as well
        MyNotification.Number := 18;
        MyNotification.EnableSound := False;
        // Send message to the notification center
        NotificationCenter1.PresentNotification(MyNotification);
      finally
        MyNotification.DisposeOf;
      end;
    end;
    • For C++:
    void __fastcall TForm1::PresentNotificationClick(TObject *Sender)
    {
      if (NotificationCenter1->Supported()) {
               TNotification *myNotification = NotificationCenter1->CreateNotification();
               __try { 
                       myNotification->Name = "MyNotification";
                       myNotification->AlertBody = "C++ for your mobile device is here!";
                       // Set Icon Badge Number (for iOS) or message number (for Android) as well
                       myNotification->Number = 18;
                       myNotification->EnableSound = False;
                       // Send notification to the notification center
                       NotificationCenter1->PresentNotification(myNotification);
              }
              __finally {  
                       myNotification->DisposeOf();
              }
     }
     
    }

Customizing the Notification Sound

You can use a customized sound for the notification message immediately through the SoundName property of the TNotification object.

You need to create an instance of the TNotification class, define the EnableSound and the SoundName properties. You also need to indicate the full path to the file sound and the file extension.

  1. Drop a new TButton to the form.
  2. In the Object Inspector, change the Name property to SoundNotification.
  3. Create the OnClick event of the SoundNotification button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the SoundNotification button by adding the following code:
    • For Delphi:
    procedure TForm1.SoundNotificationClick(Sender: TObject);
    var
      MyNotification: TNotification;
    begin
      MyNotification := NotificationCenter1.CreateNotification;
      try
        MyNotification.Name := 'MyNotification';
        MyNotification.AlertBody := 'Delphi for your mobile device is here!';
        MyNotification.EnableSound := True;
        MyNotification.SoundName := GetSoundName;
        MyNotification.FireDate := Now + EncodeTime(0, 0, 10, 0);
        // Send message to the notification center
        NotificationCenter1.ScheduleNotification(MyNotification);
      finally
        MyNotification.Free;
      end;
    end;
    • For C++:
      • In the .cpp file, add the following code:
    void __fastcall TForm1::SoundNotificationClick(TObject *Sender)
    {
    TNotification *myNotification = NotificationCenter1->CreateNotification();
            __try {
                myNotification->Name = "MyNotification";
                myNotification->AlertBody = "C++ for your mobile device is here!";
                myNotification->EnableSound = true;
                myNotification->SoundName = GetSoundName();
                myNotification->FireDate = Now() + EncodeTime(0, 0, 10, 0);
                // Send notification to the notification center
               NotificationCenter1->ScheduleNotification(myNotification);
            }
            __finally {
                myNotification->Free();
            }
    }
  5. Declare the GetSoundName function.
    • For Delphi:
      • Set the GetSoundName declaration in the private section of the unit.
      • Add the System.IOUtils to the project uses clauses.
    uses
      System.IOUtils;
    private
        function GetSoundName: string;
    • For C++:
      • In the header file (.h file), add the following declaration:
      • Set the GetSoundName declaration in the private section of the unit.
      • Include the System.IOUtils.hpp to the project uses clauses.
    #include <System.IOUtils.hpp>
    private:    // User declarations
         __fastcall  UnicodeString GetSoundName ();
  6. Implement the GetSoundName function.
    Note: Depending on the target operating system, the sound data should be a different file extension.
    • For Delphi:
    {$R *.fmx}
    function TForm1.GetSoundName: string;
    begin
    {$IFDEF IOS}
      Result := 'myiOSSound.caf';
    {$ENDIF}
    {$IFDEF ANDROID}
      Result := TPath.Combine(TPath.GetSharedDocumentsPath, 'myAndroidSound.mp3');
    {$ENDIF}
    end;
    • For C++:
      • In the .cpp file, add the following code:
    UnicodeString __fastcall TForm1::GetSoundName ()
    {
        UnicodeString result;
    #if defined(_PLAT_IOS)
        result = "myiOSSound.caf";
    #endif
    #if defined(__ANDROID__)
        result = System::Ioutils::TPath::Combine(System::Ioutils::TPath::GetSharedDocumentsPath(), "myAndroidSound.mp3");
    #endif
        return result;
      //
    }
  7. Add the sound files to your project:
    • Find the myAndroidSound.mp3 and myiOSSound.caf files in the Windows Explorer, and drag them to the Project Manager. Drop them on the name of your project.
      Note: The sound files myAndroidSound.mp3 and myiOSSound.caf are not included in the RAD Studio installation. You can use any MP3 and CAF files that you have, but remember to change the name in the code snippet above to the name of your files. See this link for more information on how to convert MP3 files to CAF format: How to convert MP3 to CAF
    • In the Confirm dialog, click Yes to add the sound files to your project.
  8. Open the Deployment Manager to ensure that the sound files are deployed with your application. You can see the corresponding entries in the remote path column:
  9. Change the remote path of the added files in the Deployment Manager:
    • For iOS: .\
    • For Android: assets\

Notification Banner or Notification Alert

By default, your application shows the notification banner:

  • Notification Banner on iPad
    IOSNotificationBanner.PNG
  • Notification Banner on Android devices
    Android
  • Notification Alert (only for iOS devices)
    IOSNotificationAlert.PNG

To use a notification alert instead of a notification banner (only for iOS devices), the end user needs to change the Alert style to Alerts through the configuration page of Notification Center, available in the device Settings:

IOSNotificationCenterOption.PNG

Add Action to the Notification Alert (iOS Only)

You can also customize an alert by adding an Action button that opens the application.

To customize an Alert Action, you need to set the AlertAction field to the Action button name, and then set the HasAction field to True, as follows.

  1. Drop a new TButton to the form.
  2. In the Object Inspector, change the Name property to ActionNotification.
  3. Create the OnClick event of the ActionNotification button by double-clicking the button.
  4. Implement the event handler for the OnClick event of the ActionNotification button by adding the following code:
    • For Delphi:
    procedure TForm1.ActionNotificationClick(Sender: TObject);
    var
      MyNotification: TNotification;
    begin
       MyNotification := NotificationCenter1.CreateNotification;
      try
        MyNotification.Name := 'MyNotification';
        MyNotification.AlertBody := 'Delphi for iOS is here! ';
        MyNotification.Number := 2;
        MyNotification.AlertAction := 'Launch';
        MyNotification.HasAction := True;
        MyNotification.FireDate := Now + EncodeTime(0, 0, 20, 0);
        NotificationCenter1.ScheduleNotification(MyNotification);
      finally
        MyNotification.DisposeOf;
      end;
    end;
    • For C++:
    void __fastcall TForm1::ActionNotificationClick(TObject *Sender)
    {
       if (NotificationCenter1->Supported()) {
               TNotification *myNotification = NotificationCenter1->CreateNotification();
               __try {
                       myNotification->Name = "MyNotification";
                       myNotification->AlertBody = "C++ for iOS is here!";
                       myNotification->Number = 2;
                       myNotification->AlertAction = "Launch";
                       myNotification->HasAction = True;
                       myNotification->FireDate = Now() + EncodeTime(0,0,20,0);
                       NotificationCenter1->ScheduleNotification(myNotification);
               }
               __finally {
                       myNotification->DisposeOf();
               }
       }
     }
Note: Only iOS devices support the notification alert feature.

The notification alert opens at the time that was specified through the FireDate field.

IOSNotificationAlert.PNG

Add Action to Notifications

The TNotificationCenter class provides the onReceiveLocalNotification event handler that allows you to write a response when the user clicks the notification message in the notification center. To write the response, double-click the TNotificationCenter component on the Form Designer, and then implement the OnReceiveLocalNotification event handler.

The following code snippet implements a response to show a message box that says "The <Notification name>" notification clicked."

  • For Delphi:
 procedure TForm1.NotificationCenter1ReceiveLocalNotification(Sender: TObject; ANotification: TNotification);
   begin
     ShowMessage('The ' + ANotification.Name + ' notification clicked.' );
   end;
  • For C++:
void __fastcall TForm1::NotificationCenter1ReceiveLocalNotification(TObject *Sender, TNotification *ANotification)
{
       ShowMessage("The " + ANotification->Name + " notification clicked.");
}



MyNotification iOS.png

Running the Application

To run the application, either choose Run > Run or press F9. Click the different buttons to schedule or present notifications in your device.

See Also

Samples

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