How do I add to calendar without user prompt UWP C#

Question

I am creating a Windows10 app, specifically for WindowsPhone.

The app needs to add an appointment to the users calendar. So far I have managed to do this but the user has to authorise each appointment.

Here is the code I have (pulled pretty much straight out of the UWP examples on GitHub):

private async void CreateTestCalendarEntry_Click(object sender, RoutedEventArgs e)
{
    string errorMessage = null;
    var appointment = new Windows.ApplicationModel.Appointments.Appointment();

    // StartTime
    var date = DateTime.Now;
    var timeZoneOffset = TimeZoneInfo.Local.GetUtcOffset(DateTime.Now);
    var startTime = new DateTimeOffset(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, timeZoneOffset);
    appointment.StartTime = startTime;

    // Subject
    appointment.Subject = "Test Calendar Entry " + date.ToString();

    if (appointment.Subject.Length > 255)
    {
        errorMessage = "The subject cannot be greater than 255 characters.";
    }

    // Location
    appointment.Location = "Japan";

    if (appointment.Location.Length > 32768)
    {
        errorMessage = "The location cannot be greater than 32,768 characters.";
    }

    // Details
    appointment.Details = "Details";

    if (appointment.Details.Length > 1073741823)
    {
        errorMessage = "The details cannot be greater than 1,073,741,823 characters.";
    }

    // Duration
    // All Day
    appointment.AllDay = true;

    // Reminder            
    appointment.Reminder = TimeSpan.FromDays(1);

    //Busy Status            
    appointment.BusyStatus = Windows.ApplicationModel.Appointments.AppointmentBusyStatus.WorkingElsewhere;

    // Sensitivity            
    appointment.Sensitivity = Windows.ApplicationModel.Appointments.AppointmentSensitivity.Public;

    var rect = new Rect(new Point(Window.Current.Bounds.Width / 2, Window.Current.Bounds.Height / 2), new Size());
    String appointmentId = await Windows.ApplicationModel.Appointments.AppointmentManager.ShowAddAppointmentAsync(appointment, rect, Windows.UI.Popups.Placement.Default);

}

Using this code, the await line opens the users calendar and displays the following, where the user can authorise or delete:

Hitting the save button, does as expected.

The problem - suppose I have 20 appointments to add to the users calendar, the user isn't going to want to authorise each one. How do I create an appointment without leaving my app and without the user needing to authorise it?

Answer 1

This can be done by writing to your own custom calendar. The required lines of code are these:

async private Task CreateCalenderEntry() 
    { 
        // 1. get access to appointmentstore 
        var appointmentStore = await AppointmentManager.RequestStoreAsync(AppointmentStoreAccessType.AppCalendarsReadWrite);

        // 2. get calendar 
        var appCustomApptCalendar = await appointmentStore.CreateAppointmentCalendarAsync("MyCalendar");

        // 3. create new Appointment 
        var appo = new Windows.ApplicationModel.Appointments.Appointment();

        // appointment properties 
        appo.AllDay = true; 
        appo.Subject = "Mein Termin";            
        appo.StartTime = DateTime.Now;

        //  4. add 
        await appCustomApptCalendar.SaveAppointmentAsync(appo); 
    }

I just tried it on Windows 10 Desktop and it worked. Should work on W10Mobile, too. However, it requires that the user shows the custom calendar. I think this should work for you.

I once wrote a blogpost (in German) covering this: https://blogs.msdn.microsoft.com/dmx/2014/07/24/termine-im-windows-phone-per-api-anlegen-ohne-broker/ It also explains that this even works from background. (to understand the text just use http://www.bing.com/translator if code alone is not sufficient, sorry for the inconvenience).