How To: Retrieve Outlook calendar items using Find and FindNext methods

In my previous articles I described how to use the Find and FindNext methods of the Items class against mail and contact items. Today we will have a closer look at calendar items. For example, how can we collect all Outlook appointments the user has assigned for the rest of the day? The Find and FindNext methods can help us in this task. As you may remember, Microsoft suggests using these methods because they are faster than Restrict in case you have a small number of items in the collection.

In the sample code I am going to get all the appointments that are:

• currently in the process (were started earlier);
• going to begin and end at the specified time (in the middle of our timeline);
• start before the end border and end after the specified time (outside of the specified time).

Let’s take the current time as the start time and midnight as the end time, i.e. collect all the appointments assigned for the rest of the day.

Here is a sample code that collects the appointments and outputs the Subject, Organizer and Location properties to the Debug window. You can use the Output window in Visual Studio when debugging the code or the DebugView utility to see the results.

C# and Add-in Express:

using System.Text;
using System.Diagnostics;
// ...
private void FindActiveAppointments(Outlook.MAPIFolder folder)
{
    string dateTimeStart = DateTime.Now.ToString("MM/dd/yyyy hh:mm tt");
    DateTime dt = new DateTime(DateTime.Now.Year, DateTime.Now.Month,
                               DateTime.Now.Day, 23, 59, 00, 00);
    string dateTimeEnd = dt.ToString("MM/dd/yyyy hh:mm tt");
    string searchCriteria = "[Start]< =\"" + dateTimeEnd + "\"" + " AND [End]>=\""+
                                                              dateTimeStart +"\"";
    StringBuilder strBuilder = null;
    int counter = default(int);
    Outlook._AppointmentItem appItem = null;
    Outlook.Items folderItems = null;
    object resultItem = null;
    try
    {
        folderItems = folder.Items;
        folderItems.IncludeRecurrences = true;
        folderItems.Sort("[Start]");
        if (folderItems.Count > 0)
        {
            resultItem = folderItems.Find(searchCriteria);
            if (resultItem != null)
            {
                strBuilder = new StringBuilder();
                do
                {
                    if (resultItem is Outlook._AppointmentItem)
                    {
                        counter++;
                        appItem = resultItem as Outlook._AppointmentItem;
                        strBuilder.AppendLine("#" + counter.ToString() +
                                              "\tSubject: " + appItem.Subject +
                                              "\tOrganizer: " + appItem.Organizer +
                                              "\tLocation: " + appItem.Location);
                    }
                    Marshal.ReleaseComObject(resultItem);
                    resultItem = folderItems.FindNext();
               }
               while (resultItem != null);
           }
       }
       if (strBuilder != null)
           Debug.WriteLine(strBuilder.ToString());
       else
           Debug.WriteLine("There is no match in the " +
                              folder.Name + " folder.");
   }
   catch (Exception ex)
   {
       System.Windows.Forms.MessageBox.Show(ex.Message);
   }
   finally
   {
       if (folderItems != null) Marshal.ReleaseComObject(folderItems);
   }
}

VB.NET and Add-in Express:

Imports System.Text
Imports System.Diagnostics
' ...
Private Sub FindActiveAppointments(folder As Outlook.MAPIFolder)
    Dim dateTimeStart As String = DateTime.Now.ToString("MM/dd/yyyy hh:mm tt")
    Dim dt As DateTime = New DateTime(DateTime.Now.Year, DateTime.Now.Month, _
                                      DateTime.Now.Day, 23, 59, 0, 0)
    Dim dateTimeEnd As String = dt.ToString("MM/dd/yyyy hh:mm tt")
    Dim searchCriteria As String = "[Start]< =""" + dateTimeEnd + """ AND [End]>=""" + _
                                                                dateTimeStart + """"
    Dim strBuilder As StringBuilder = Nothing
    Dim counter As Integer = 0
    Dim appItem As Outlook._AppointmentItem = Nothing
    Dim folderItems As Outlook.Items = Nothing
    Dim resultItem As Object = Nothing
    Try
        folderItems = folder.Items
        folderItems.IncludeRecurrences = True
        folderItems.Sort("[Start]")
        If (folderItems.Count > 0) Then
            resultItem = folderItems.Find(searchCriteria)
            If Not IsNothing(resultItem) Then
                strBuilder = New StringBuilder()
                Do
                    If (TypeOf (resultItem) Is Outlook._AppointmentItem) Then
                        counter += 1
                        appItem = resultItem
                        strBuilder.AppendLine("#" + counter.ToString() + _
                                              " Subbject: " + appItem.Subject + _
                                              " Organizer: " + appItem.Organizer + _
                                              " Location: " + appItem.Location)
                    End If
                    Marshal.ReleaseComObject(resultItem)
                    resultItem = folderItems.FindNext()
                Loop Until IsNothing(resultItem)
            End If
        End If
        If Not IsNothing(strBuilder) Then
            Debug.WriteLine(strBuilder.ToString())
        Else
            Debug.WriteLine("There is no match in the " + _
                               folder.Name + " folder.")
        End If
    Catch ex As Exception
        System.Windows.Forms.MessageBox.Show(ex.Message)
    Finally
        If Not IsNothing(folderItems) Then
            Marshal.ReleaseComObject(folderItems)
        End If
    End Try
End Sub

The code for VSTO and Add-in Express based add-ins is the same. Just remember two simple things when switching between these 2 kinds of add-ins:

• To declare required namespaces at the beginning of the file.
• To use the Application property and OutlookApp property in VSTO and Add-in Express based add-ins respectively to get an instance of the Application.

C# and VSTO:

using System.Runtime.InteropServices;
using System.Diagnostics;
// ...
private void FindActiveAppointments(Outlook.MAPIFolder folder)
{
    string dateTimeStart = DateTime.Now.ToString("MM/dd/yyyy hh:mm tt");
    DateTime dt = new DateTime(DateTime.Now.Year, DateTime.Now.Month,
                               DateTime.Now.Day, 23, 59, 00, 00);
    string dateTimeEnd = dt.ToString("MM/dd/yyyy hh:mm tt");
    string searchCriteria = "[Start]< =\"" + dateTimeEnd + "\"" + " AND [End]>=\"" +
                                                                dateTimeStart + "\"";
    StringBuilder strBuilder = null;
    int counter = default(int);
    Outlook._AppointmentItem appItem = null;
    Outlook.Items folderItems = null;
    object resultItem = null;
    try
    {
        folderItems = folder.Items;
        folderItems.IncludeRecurrences = true;
        folderItems.Sort("[Start]");
        if (folderItems.Count > 0)
        {
            resultItem = folderItems.Find(searchCriteria);
            if (resultItem != null)
            {
                strBuilder = new StringBuilder();
                do
                {
                    if (resultItem is Outlook._AppointmentItem)
                    {
                        counter++;
                        appItem = resultItem as Outlook._AppointmentItem;
                        strBuilder.AppendLine("#" + counter.ToString() +
                                              "\tSubject: " + appItem.Subject +
                                              "\tOrganizer: " + appItem.Organizer +
                                              "\tLocation: " + appItem.Location);
                    }
                    Marshal.ReleaseComObject(resultItem);
                    resultItem = folderItems.FindNext();
                }
                while (resultItem != null);
            }
        }
        if (strBuilder != null)
            Debug.WriteLine(strBuilder.ToString());
        else
            Debug.WriteLine("There is no match in the " +
                               folder.Name + " folder.");
    }
    catch (Exception ex)
    {
        System.Windows.Forms.MessageBox.Show(ex.Message);
    }
    finally
    {
        if (folderItems != null) Marshal.ReleaseComObject(folderItems);
    }
}

VB.NET and VSTO:

Imports System.Runtime.InteropServices
Imports System.Diagnostics
' ...
Private Sub FindActiveAppointments(folder As Outlook.MAPIFolder)
    Dim dateTimeStart As String = DateTime.Now.ToString("MM/dd/yyyy hh:mm tt")
    Dim dt As DateTime = New DateTime(DateTime.Now.Year, DateTime.Now.Month, _
                                      DateTime.Now.Day, 23, 59, 0, 0)
    Dim dateTimeEnd As String = dt.ToString("MM/dd/yyyy hh:mm tt")
    Dim searchCriteria As String = "[Start]< =""" + dateTimeEnd + """ AND [End]>=""" + _
                                                                    dateTimeStart + """"
    Dim strBuilder As StringBuilder = Nothing
    Dim counter As Integer = 0
    Dim appItem As Outlook._AppointmentItem = Nothing
    Dim folderItems As Outlook.Items = Nothing
    Dim resultItem As Object = Nothing
    Try
        folderItems = folder.Items
        folderItems.IncludeRecurrences = True
        folderItems.Sort("[Start]")
        If (folderItems.Count > 0) Then
            resultItem = folderItems.Find(searchCriteria)
            If Not IsNothing(resultItem) Then
                strBuilder = New StringBuilder()
                Do
                    If (TypeOf (resultItem) Is Outlook._AppointmentItem) Then
                        counter += 1
                        appItem = resultItem
                        strBuilder.AppendLine("#" + counter.ToString() + _
                                              " Subbject: " + appItem.Subject + _
                                              " Organizer: " + appItem.Organizer + _
                                              " Location: " + appItem.Location)
                    End If
                    Marshal.ReleaseComObject(resultItem)
                    resultItem = folderItems.FindNext()
                Loop Until IsNothing(resultItem)
            End If
        End If
        If Not IsNothing(strBuilder) Then
            Debug.WriteLine(strBuilder.ToString())
        Else
            Debug.WriteLine("There is no match in the " + _
                           folder.Name + " folder.")
        End If
    Catch ex As Exception
        System.Windows.Forms.MessageBox.Show(ex.Message)
    Finally
        If Not IsNothing(folderItems) Then
        Marshal.ReleaseComObject(folderItems)
    End If
    End Try
End Sub

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