Filter and display computed properties when enumerating items in a folder

This example shows how to filter and display computed properties when enumerating items in a folder.

Example

The Table object represents a set of item data from a Folder or Search object. The Row object represents rows of data in a Table. The Columns object represents properties of the Table. You can add certain properties to the Table object by using the Add(String) method of the Columns object. You can filter certain properties by using the Restrict(String) method of the Table object. However, some properties cannot be added to the Table object by using Columns.Add, nor can they be filtered by using the Restrict method. The following table describes whether properties are supported for the Table object when you use the Columns.Add or Restrict method.

The following table lists known invalid properties that cannot be added to the Table object by using Columns.Add. If you attempt to add a property from this list, Outlook will raise an error.

Although some computed properties cannot be added to the column set for a table, the following code example works around this limitation. GetToDoItems uses a DASL query to restrict the items that appear in the Table. If the computed property has a namespace representation, the namespace representation is used to create a DASL query that restricts the Table object to return rows for a specified value of the computed property. GetToDoItems gets items in the Inbox where the value of the IsMarkedAsTask property is equal to true, and then assigns values to certain task properties such as TaskSubject, TaskDueDate, TaskStartDate, and TaskCompletedDate. Finally, those properties are written to the trace listeners of the Listeners collection.

If you use Visual Studio to test this code example, you must first add a reference to the Microsoft Outlook 15.0 Object Library component and specify the Outlook variable when you import the Microsoft.Office.Interop.Outlook namespace. The using statement must not occur directly before the functions in the code example but must be added before the public Class declaration. The following line of code shows how to do the import and assignment in C#.

using Outlook = Microsoft.Office.Interop.Outlook;

private void GetToDoItems()
{
    // Obtain Inbox
    Outlook.Folder folder =
        Application.Session.GetDefaultFolder(
        Outlook.OlDefaultFolders.olFolderInbox)
        as Outlook.Folder;
    // DASL filter for IsMarkedAsTask
    string filter = "@SQL=" + "\"" +
        "http://schemas.microsoft.com/mapi/proptag/0x0E2B0003"
        + "\"" + " = 1";
    Outlook.Table table =
        folder.GetTable(filter,
        Outlook.OlTableContents.olUserItems);
    table.Columns.Add("TaskStartDate");
    table.Columns.Add("TaskDueDate");
    table.Columns.Add("TaskCompletedDate");
    // Use GUID/ID to represent TaskSubject
    table.Columns.Add(
        "http://schemas.microsoft.com/mapi/id/" +
        "{00062008-0000-0000-C000-000000000046}/85A4001E");
    while (!table.EndOfTable)
    {
        Outlook.Row nextRow = table.GetNextRow();
        StringBuilder sb = new StringBuilder();
        sb.AppendLine("Task Subject: " + nextRow[9]);
        sb.AppendLine("Start Date: "
            + nextRow["TaskStartDate"]);
        sb.AppendLine("Due Date: "
            + nextRow["TaskDueDate"]);
        sb.AppendLine("Completed Date: "
            + nextRow["TaskCompletedDate"]);
        sb.AppendLine();
        Debug.WriteLine(sb.ToString());
    }
}

See also

• Search and filter