Question

我有一个.Net Webservice，有以下两种方法：

[WebMethod(EnableSession = true)]
public void A()
{
   HttpSessionState session = Session;

   Thread thread = new Thread(B);
   thread.Start();
}

[WebMethod(EnableSession = true)]
public void B()
{
   HttpSessionState session = Session;
}

方案1）当我直接调用 B 方法时，会话不为空

方案2）但是当我打电话给 A 时，在 B 中，会话和HttpContext.Current都为空。

为什么呢？如何在第二种情况下在 B 中启用会话？如何在A中访问会话？我应该把它的会话传递给B吗？如果是的话怎么样？

方法B不应将会话作为参数。

谢谢，

Answer 1

这是因为你在一个新线程中开始了B.

参见http://forums.asp.net/t/1276840.aspx 要么 http://forums.asp.net/t/1630651.aspx/1

Answer 2

[WebMethod(EnableSession = true)]
public void A()
{
   HttpSessionState session = Session;

   Action action = () => B_Core(session);
   Thread thread = new Thread(action);
   thread.Start();
}

[WebMethod(EnableSession = true)]
public void B()
{
   HttpSessionState session = Session;
   B_Core(session);
}
private void B_Core(HttpSessionState session)
{
    // todo
}

Answer 3

我必须使用全局字段：

/// <summary>
/// Holds the current session for using in threads.
/// </summary>
private HttpSessionState CurrentSession;

[WebMethod(EnableSession = true)]
public void A()
{
   CurrentSession = Session;

   Thread thread = new Thread(B);
   thread.Start();
}

[WebMethod(EnableSession = true)]
public void B()
{
  //for times that method is not called as a thread
  CurrentSession = CurrentSession == null ? Session : CurrentSession;

   HttpSessionState session = CurrentSession;
}

如何在Threaded .Net Webservice中启用会话？

3 个答案: