好的，到目前为止，我获得的有关该主题的最佳信息是在这个线程上：EWS-API-创建日历并与审阅者共享权限 https://stackoverflow.com/questions/7503613/ews-api-create-calendar-and-share-with-reviewer-permissions?answertab=oldest#tab-top。我尝试在该线程上问这个问题，但实际上我将其作为答案发布，因此它被管理员删除（我的错！）
免责声明：我是一名系统管理员，从事行业和兼职开发工作……所以请原谅任何术语的误用或措辞上的混乱。
另外，我在这里用 C# 工作，仅供参考。
我已阅读微软的消息协议规范，并了解需要在消息项目上创建某些扩展属性才能正确创建共享邀请对象我从上面提到的帖子中了解到，我可以创建具有扩展属性的消息对象（SetExtendedProperty(extprop,value)准确地说）。我知道我必须手动创建我正在设置的扩展属性new ExtendedProperty()并在每个属性上填充正确的父 GUID、十六进制 ID 和数据类型。据我所知，这或多或少是一种“解决方法”，因为 API 中没有内置的固有共享对象管理功能......
但我遇到了一个障碍，需要一些澄清......
我想手动创建共享邀请（通过客户端，“用户”方式），然后附加到发送邀请的用户的“已发送邮件”框中的消息。我想枚举与构建类似对象所需的所有可能属性，以便我可以将其用作模板并将我的对象属性与原始邀请进行比较。我可以很好地获取消息并找到许多属性，但找不到任何“特殊”属性。我能发现的唯一区分消息项目的事实是它是IPM.Sharing项目类别及其附件sharing_metadata.xml.
但是我现在假设我们可以通过使用扩展属性通过 API 创建共享邀请，这并不一定意味着我们可以通过 API 读取这些属性，这是正确的吗？
我尝试枚举扩展属性的所有内容似乎都不起作用，并且总是返回任何内容而不是扩展属性数组。也许我做得不对，但我想在花费无数时间尝试实现不可能的事情之前先问这个问题。
因此，如果我无法正确枚举扩展属性，是否有可能使用类似的东西ExFolders or MFCMAPI或获得这些属性的东西？？？
有什么想法/建议/批评吗？
Thanks!
UPDATE:
这是我正在尝试为用户日历文件夹创建共享邀请的功能...我已经评论了我遇到的困难以及我没有完全理解的内容：
public void CreateCalendarSharingRequest(string folderID, string owner, string sharedToUser)
{
// LOAD OUR CUSTOM PROPERTIES
Guid PropertySetSharing = new Guid("{00062040-0000-0000-C000-000000000046}");
Guid PropertySetInternetHeaders = new Guid("{00020386-0000-0000-C000-000000000046}");
// Sharing Properties
ExtendedPropertyDefinition PidLidSharingProviderGuid = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A01, MapiPropertyType.CLSID);
ExtendedPropertyDefinition PidLidSharingProvidorName = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A02, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingFlavor = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A18, MapiPropertyType.Integer);
ExtendedPropertyDefinition PidLidSharingRemoteStoreUid = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A48, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingRemoteUid = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A06, MapiPropertyType.String);
ExtendedPropertyDefinition PidTagMessageClass = new ExtendedPropertyDefinition(0x001A, MapiPropertyType.String);
ExtendedPropertyDefinition PidTagNormalizedSubject = new ExtendedPropertyDefinition(0x0E1D, MapiPropertyType.String);
ExtendedPropertyDefinition PidTagSubjectPrefix = new ExtendedPropertyDefinition(0x003D, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingCapabilities = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A17, MapiPropertyType.Integer);
ExtendedPropertyDefinition PidLidSharingInitiatorEntryId = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A09, MapiPropertyType.Binary);
ExtendedPropertyDefinition PidLidSharingConfigurationUrl = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A24, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingInitiatorName = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A07, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingInitiatorSMTP = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A08, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingLocalType = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A14, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingRemoteType = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A1D, MapiPropertyType.String);
ExtendedPropertyDefinition PidLidSharingRemoteName = new ExtendedPropertyDefinition(PropertySetSharing, 0x8A05, MapiPropertyType.String);
// Internet Header Properties
ExtendedPropertyDefinition PidNameContentClass = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "Content-Class", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingCapabilities = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Capabilities", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingConfigUrl = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Config-Url", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingFlavor = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Flavor", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingLocalType = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Local-Type", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingRemoteName = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Remote-Name", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingRemoteStoreUid = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Remote-Store-Uid", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingRemoteType = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Remote-Type", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingRemoteUid = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Remote-Uid", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingProviderGuid = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Provider-Guid", MapiPropertyType.String);
ExtendedPropertyDefinition PidNameXSharingProviderName = new ExtendedPropertyDefinition(PropertySetInternetHeaders, "X-Sharing-Provider-Name", MapiPropertyType.String);
// Bind to the web services and currently selected folder
// Get the current list of delegates for this folder
ExchangeService service = GetExchangeService();
// Create a new message
EmailMessage invitationRequest = new EmailMessage(service);
invitationRequest.Subject = "I'd like to share my calendar with you";
invitationRequest.Body = "Send by Exchange Administrator on behalf of user";
invitationRequest.From = GetSMTPAddress(owner);
invitationRequest.ItemClass = "IPM.Sharing";
invitationRequest.SetExtendedProperty(PidNameContentClass, "Sharing");
invitationRequest.SetExtendedProperty(PidTagMessageClass, "IPM.Sharing");
invitationRequest.SetExtendedProperty(PidLidSharingFlavor,0x20310); /* Indicates Invitation for a special folder */
invitationRequest.SetExtendedProperty(PidNameXSharingFlavor, "20310"); /* Text representation of SharingFlavor value */
invitationRequest.SetExtendedProperty(PidLidSharingProviderGuid, PropertySetSharing.ToString());
invitationRequest.SetExtendedProperty(PidNameXSharingProviderGuid, PropertySetSharing.ToString());
invitationRequest.SetExtendedProperty(PidLidSharingCapabilities, 0x40290); /* value for Special Folders */
invitationRequest.SetExtendedProperty(PidNameXSharingCapabilities, "40290"); /* Test representation of SharingCapabilities value */
// THIS IS WHERE IM STUCK - I understand how to set some of the properties like above, but then
// it starts needing the entryID properties for the folder being shared, etc...and I'm not entirely
// sure which properties I have to set and how many can/will be autopopulated by the transport provider
// All i wanna do is send an invite message for sharing the calendar folder from one user to another!
// Add recipient info
//invitationRequest.ToRecipients.Add(sharedToUser);
//invitationRequest.SendAndSaveCopy();
}
