我正在尝试创建一个可以执行许多操作的Web应用程序，但我目前关注的是收件箱数量。我想使用EWS StreamSubscription，以便我可以获取每个事件的通知并返回收件箱中的项目总数。我如何在MVC方面使用它？我确实找到了一些我将要测试的Microsoft教程中的代码，但我无法想象如何在MVC世界中使用它，即模型是什么，如果模型是计数，那么每次都会得到通知Exchange Server等中发生事件。
这是我从Microsoft下载的代码，但是我无法理解如何将计数转换为json并在新的更改事件发生时立即将其推送到客户端。注意：此代码未更改，因此它不会返回计数。
using System;
using System.Linq;
using System.Net;
using System.Threading;
using Microsoft.Exchange.WebServices.Data;
namespace StreamingNotificationsSample
{
internal class Program
{
private static AutoResetEvent _Signal;
private static ExchangeService _ExchangeService;
private static string _SynchronizationState;
private static Thread _BackroundSyncThread;
private static StreamingSubscriptionConnection CreateStreamingSubscription(ExchangeService service,
StreamingSubscription subscription)
{
var connection = new StreamingSubscriptionConnection(service, 30);
connection.AddSubscription(subscription);
connection.OnNotificationEvent += OnNotificationEvent;
connection.OnSubscriptionError += OnSubscriptionError;
connection.OnDisconnect += OnDisconnect;
connection.Open();
return connection;
}
private static void SynchronizeChangesPeriodically()
{
while (true)
{
try
{
// Get all changes from the server and process them according to the business
// rules.
SynchronizeChanges(new FolderId(WellKnownFolderName.Inbox));
}
catch (Exception ex)
{
Console.WriteLine("Failed to synchronize items. Error: {0}", ex);
}
// Since the SyncFolderItems operation is a
// rather expensive operation, only do this every 10 minutes
Thread.Sleep(TimeSpan.FromMinutes(10));
}
}
public static void SynchronizeChanges(FolderId folderId)
{
bool moreChangesAvailable;
do
{
Console.WriteLine("Synchronizing changes...");
// Get all changes since the last call. The synchronization cookie is stored in the _SynchronizationState field.
// Only the the ids are requested. Additional properties should be fetched via GetItem calls.
var changes = _ExchangeService.SyncFolderItems(folderId, PropertySet.IdOnly, null, 512,
SyncFolderItemsScope.NormalItems, _SynchronizationState);
// Update the synchronization cookie
_SynchronizationState = changes.SyncState;
// Process all changes
foreach (var itemChange in changes)
{
// This example just prints the ChangeType and ItemId to the console
// LOB application would apply business rules to each item.
Console.Out.WriteLine("ChangeType = {0}", itemChange.ChangeType);
Console.Out.WriteLine("ChangeType = {0}", itemChange.ItemId);
}
// If more changes are available, issue additional SyncFolderItems requests.
moreChangesAvailable = changes.MoreChangesAvailable;
} while (moreChangesAvailable);
}
public static void Main(string[] args)
{
// Create new exchange service binding
// Important point: Specify Exchange 2010 with SP1 as the requested version.
_ExchangeService = new ExchangeService(ExchangeVersion.Exchange2010_SP1)
{
Credentials = new NetworkCredential("user", "password"),
Url = new Uri("URL to the Exchange Web Services")
};
// Process all items in the folder on a background-thread.
// A real-world LOB application would retrieve the last synchronization state first
// and write it to the _SynchronizationState field.
_BackroundSyncThread = new Thread(SynchronizeChangesPeriodically);
_BackroundSyncThread.Start();
// Create a new subscription
var subscription = _ExchangeService.SubscribeToStreamingNotifications(new FolderId[] {WellKnownFolderName.Inbox},
EventType.NewMail);
// Create new streaming notification conection
var connection = CreateStreamingSubscription(_ExchangeService, subscription);
Console.Out.WriteLine("Subscription created.");
_Signal = new AutoResetEvent(false);
// Wait for the application to exit
_Signal.WaitOne();
// Finally, unsubscribe from the Exchange server
subscription.Unsubscribe();
// Close the connection
connection.Close();
}
private static void OnDisconnect(object sender, SubscriptionErrorEventArgs args)
{
// Cast the sender as a StreamingSubscriptionConnection object.
var connection = (StreamingSubscriptionConnection) sender;
// Ask the user if they want to reconnect or close the subscription.
Console.WriteLine("The connection has been aborted; probably because it timed out.");
Console.WriteLine("Do you want to reconnect to the subscription? Y/N");
while (true)
{
var keyInfo = Console.ReadKey(true);
{
switch (keyInfo.Key)
{
case ConsoleKey.Y:
// Reconnect the connection
connection.Open();
Console.WriteLine("Connection has been reopened.");
break;
case ConsoleKey.N:
// Signal the main thread to exit.
Console.WriteLine("Terminating.");
_Signal.Set();
break;
}
}
}
}
private static void OnNotificationEvent(object sender, NotificationEventArgs args)
{
// Extract the item ids for all NewMail Events in the list.
var newMails = from e in args.Events.OfType<ItemEvent>()
where e.EventType == EventType.NewMail
select e.ItemId;
// Note: For the sake of simplicity, error handling is ommited here.
// Just assume everything went fine
var response = _ExchangeService.BindToItems(newMails,
new PropertySet(BasePropertySet.IdOnly, ItemSchema.DateTimeReceived,
ItemSchema.Subject));
var items = response.Select(itemResponse => itemResponse.Item);
foreach (var item in items)
{
Console.Out.WriteLine("A new mail has been created. Received on {0}", item.DateTimeReceived);
Console.Out.WriteLine("Subject: {0}", item.Subject);
}
}
private static void OnSubscriptionError(object sender, SubscriptionErrorEventArgs args)
{
// Handle error conditions.
var e = args.Exception;
Console.Out.WriteLine("The following error occured:");
Console.Out.WriteLine(e.ToString());
Console.Out.WriteLine();
}
}
}
我只是想了解基本概念，因为什么是模型，我在哪里可以使用其他功能。
答案 0 :(得分：1)
您的问题是您将服务（EWS）与应用程序模型混淆。他们是两个不同的东西。您的模型完全由您控制，您可以随心所欲地执行任何操作。 EWS不受您的控制，只是您调用以获取数据的服务。
在您的控制器中，您呼叫EWS服务并获取计数。然后使用该计数填充模型，然后在视图中渲染该模型属性。它真的很简单。
网页没有状态。当事情发生变化时，它不会收到通知。您只需重新加载页面并获取当前状态（即，无论当前计数是什么）。
在更高级的应用程序中，例如使用Ajax的单页应用程序，您可以在后台定期查询服务。或者，您可能有一个特殊的通知服务，它使用SignalR之类的东西来通知您的SPA更改，但这些概念远比您目前更先进。您可能应该首先将您的应用程序开发为一个简单的无状态应用程序，然后改进它以添加ajax功能，或者一旦您更好地掌握了这些功能。
答案 1 :(得分：0)
这是一个非常广泛的问题，没有明确的答案。您的模型当然可以具有可以更新的“计数”属性。您找到的示例代码可能会被您的控制器使用。