EWS从所有文件夹中获取未读电子邮件的数量

Question

我正在尝试从特定用户那里获取Exchange的未读电子邮件数量.

我可以从收件箱中获得大量电子邮件,如下所示:

SearchFilter sf = new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false));
ItemView view = new ItemView(int.MaxValue);
FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, sf, view);
int unreadCount = 0;
foreach (EmailMessage i in findResults)
    {
        unreadCount++;
    }
label1.Text = unreadCount.ToString();

这非常有效.
我也可以让所有子文件夹都是收件箱:

FindFoldersResults findResults1 = service.FindFolders(
    WellKnownFolderName.Inbox,
    new FolderView(int.MaxValue) { Traversal = FolderTraversal.Deep });

foreach (Folder folder in findResults1.Folders)
{
    Console.WriteLine(folder.DisplayName);
}

问题是我无法将这两者结合在一起.
我知道我可以做嵌套的foreach循环,但我想避免这种情况.

我发现了这些问题:所有文件夹中的Exchange Web服务(EWS)FindItems,但它至少需要使用Outlook 2010才能创建AllItems文件夹.

我知道我可以创建SearchFilterCollection,但是如何添加规则以便它在Inbox和所有子文件夹中搜索未读的电子邮件？

编辑:

这是我到目前为止尝试做的事情:

private int getEmailCount()
{
    int unreadCount = 0;

    FolderView viewFolders = new FolderView(int.MaxValue) { Traversal = FolderTraversal.Deep, PropertySet = new PropertySet(BasePropertySet.IdOnly) };
    ItemView viewEmails = new ItemView(int.MaxValue) { PropertySet = new PropertySet(BasePropertySet.IdOnly) };
    SearchFilter unreadFilter = new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false));

    FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, unreadFilter, viewEmails);
    unreadCount += findResults.Count();

    FindFoldersResults inboxFolders = service.FindFolders(WellKnownFolderName.Inbox, viewFolders);

    foreach (Folder folder in inboxFolders.Folders)
    {
        findResults = service.FindItems(folder.Id, unreadFilter, viewEmails);
        unreadCount += findResults.Count();
    }

    return unreadCount;
    }

基本上这是有效的,但是当我创建了多个子文件夹时,它开始工作得很慢.
我可以用一个来获得相同的结果而不是多个查询吗？

Answer 1

我搜索了一下并创建了这个函数：

    public void getEmailCount(Action<int> callback)
    {
        int unreadCount = 0;

        FolderView viewFolders = new FolderView(int.MaxValue) { Traversal = FolderTraversal.Deep, PropertySet = new PropertySet(BasePropertySet.IdOnly) };
        ItemView viewEmails = new ItemView(int.MaxValue) { PropertySet = new PropertySet(BasePropertySet.IdOnly) };
        SearchFilter unreadFilter = new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false));
        SearchFilter folderFilter = new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(FolderSchema.DisplayName, "AllItems"));

        FindFoldersResults inboxFolders = service.FindFolders(WellKnownFolderName.Root, folderFilter, viewFolders);

        if (inboxFolders.Count() == 0)//if we don't have AllItems folder
        {
            //search all items in Inbox and subfolders
            FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, unreadFilter, viewEmails);
            unreadCount += findResults.Count();

            inboxFolders = service.FindFolders(WellKnownFolderName.Inbox, viewFolders);
            foreach (Folder folder in inboxFolders.Folders)
            {
                findResults = service.FindItems(folder.Id, unreadFilter, viewEmails);
                unreadCount += findResults.Count();
            }
        }
        else //AllItems is avilable
        {
            foreach (Folder folder in inboxFolders.Folders)
            {
                FindItemsResults<Item> findResults = service.FindItems(folder.Id, unreadFilter, viewEmails);
                unreadCount += findResults.Count();
            }
        }

        callback(unreadCount);
    }

基本上它会检查我们是否有AllItems可用的文件夹。
如果YES我们执行一个简单的查询，返回所有未读消息。
如果NO然后我们循环收件箱内的所有文件夹。这比较慢，并且取决于我们有多少个文件夹和级别。

欢迎任何修复和改进:)