使用Exchange Web Server API收集電子郵件時引發System.OutOfMemoryException

Question

我的Windows服務源代碼中出現以下錯誤：

System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' 
was thrown.
at System.Collections.Generic.List`1.set_Capacity(Int32 value) at 
System.Collections.Generic.List`1.EnsureCapacity(Int32 min) at 
System.Collections.Generic.List`1.Add(T item)

當我嘗試使用Exchange Web Server API從收件箱中加載電子郵件時。 以下是用於身份驗證和從郵箱讀取的代碼：

ExchangeService service = new 
ExchangeService(ExchangeVersion.Exchange2013_SP1);
service.Credentials = new WebCredentials("name@domain.co.uk", "*****");
service.TraceEnabled = true;
service.TraceFlags = TraceFlags.All;
service.AutodiscoverUrl("name@domain.co.uk", RedirectionUrlValidationCallBack);

//retrieve first 50 emails
int offset = 0;
int pageSize = 50;
bool moreEmails = true;
ItemView view = new ItemView(pageSize, offset, OffsetBasePoint.Beginning);

view.PropertySet = PropertySet.IdOnly;
FindItemsResults<Item> findResults;
List<EmailMessage> emails = new List<EmailMessage>();
findResults = service.FindItems(WellKnownFolderName.Inbox, view);

while (moreEmails)
{
    foreach (var item in findResults.Items)
    {
        emails.Add((EmailMessage)item);
    }

    moreEmails = findResults.MoreAvailable;

    if (moreEmails)
    {
        view.Offset += pageSize;
    }
}

 PropertySet properties = (BasePropertySet.FirstClassProperties);
 service.LoadPropertiesForItems(emails, properties);

有人告訴我錯誤位於

emails.Add（（EmailMessage）項）;

但我不確定如何解決此錯誤。 任何幫助深表感謝。

Answer 1

將調用滑動到while循環內的FindItems上。 沒有它，您只是將相同的項目添加到集合中，直到內存用完。

while (moreEmails)
{
    findResults = service.FindItems(WellKnownFolderName.Inbox, view);

    foreach (var item in findResults.Items)
    {
        emails.Add((EmailMessage)item);
    }

    moreEmails = findResults.MoreAvailable;

    if (moreEmails)
    {
        view.Offset += pageSize;
    }
}