Getting Item

To get an existing item is necessary to know the key that is passed to the method as a parameter. Use methods StiItem.GetByKey() and StiItem.GetByKeyAsync():

.NET API

...
public void GetCalendarItem()
{
    var connection = new Stimulsoft.Server.Connect.StiServerConnection("localhost:40010");
    connection.Accounts.Users.Login("UserName@example.com", "Password");

    var item = connection.Items.GetByKey("CalendarItemKey");
    if (item != null)
    {
        var calendarItem = item as StiCalendarItem;
        if (calendarItem != null)
        {
            var calendarItemDescription = calendarItem.Description;
        }
    }
}
...

Asynchronous method:

.NET API

...
public async void GetCalendarItemAsync()
{
    var connection = new Stimulsoft.Server.Connect.StiServerConnection("localhost:40010");
    await connection.Accounts.Users.LoginAsync("UserName@example.com", "Password");

    var item = await connection.Items.GetByKeyAsync("CalendarItemKey");
    if (item != null)
    {
        var calendarItem = item as StiCalendarItem;
        if (calendarItem != null)
        {
            var calendarItemDescription = calendarItem.Description;
        }
    }
}
...