阻止使用块内的调用并不会阻止范围对象被处置

Question

即使主叫线程没有离开使用范围，我的NetworkStream id也会被处理掉，我得到了：

  

＆＃34;无法访问已处置的对象。
对象名称：＆＃39; System.Net.Sockets.NetworkStream＆＃34;

我的印象是，如果我阻止启动事件订阅的调用方法，NetworkStream将保持活动状态，我做错了什么？

using (var tcpClient = server.AcceptTcpClient())
{

    using (var networkStream = tcpClient.GetStream())
    {
        //Edit: start of the code that was missing from my original question    
        using (var sr = new StreamReader(networkStream, Encoding.ASCII))
        {            
            var someVal = Login(sr, sw);
        }
        //Edit: end of the code that was missing from my original question    

        using (var sw = new StreamWriter(networkStream, Encoding.ASCII) { AutoFlush = true })
        {
            someObj.BlockingCall(sw); //calling some blocking call
        }                        
    }        
}


internal class SomeObj
{
    private StreamWriter _sw;
    private readonly ManualResetEvent _manualResetEvent;
    internal SomeObj()
    {   
        _manualResetEvent = new ManualResetEvent(false);            
    }
    internal void BlockingCall(StreamWriter sw)
    {
        try
        {
            _sw = sw;                
            dataProvider.OnHighFrequencyEvent += DataProvider_OnHighFrequencyEvent;

            _manualResetEvent.WaitOne(); // here it blocks
        }
        catch (Exception ex)
        {
            log.Error("Error subscribing to dataProvider", ex);
        }
    }

    private void DataProvider_OnHighFrequencyEvent(IData data)
    {            
            try
            {
                _sw.WriteLine(data.Payload); //here the exception occurs
            }
            catch (Exception ex)
            {
                // Cannot access a disposed object.\r\nObject name: 'System.Net.Sockets.NetworkStream                
            }
        }
    }
}

编辑：

正如彼得所说的那样，缺少了一些代码（以为我删除它时更容易阅读）我在上面添加了一条注释，显然这是导致问题的原因，你可以解释一下吗？为什么？它只处理StreamReader ......