MessageQueue.BeginReceive()空引用错误-c#
具有侦听msmq的windows服务。在OnStart方法中,有以下内容MessageQueue.BeginReceive()空引用错误-c#,c#,msmq,C#,Msmq,具有侦听msmq的windows服务。在OnStart方法中,有以下内容 protected override void OnStart(string[] args) { try { _queue = new MessageQueue(_qPath);//this part works as i had logging before and afer this call //Add MSMQ Event _queue.Receiv
protected override void OnStart(string[] args)
{
try
{
_queue = new MessageQueue(_qPath);//this part works as i had logging before and afer this call
//Add MSMQ Event
_queue.ReceiveCompleted += new ReceiveCompletedEventHandler(queue_ReceiveCompleted);//this part works as i had logging before and afer this call
_queue.BeginReceive();//This is where it is failing - get a null reference exception
}
catch(Exception ex)
{
EventLogger.LogEvent(EventSource, EventLogType, "OnStart" + _lineFeed +
ex.InnerException.ToString() + _lineFeed + ex.Message.ToString());
}
}
在哪里
private MessageQueue _queue = null;
这可以在我的机器上运行,但当部署到windows 2003服务器并作为网络服务帐户运行时,它会失败
例外记录:
Service cannot be started. System.NullReferenceException: Object reference not set to an instance of an object.
at MYService.Service.OnStart(String[] args)
at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)
已解决:
事实证明,我设置的Q必须在安全选项卡下显式地将网络服务帐户添加到其中您看到了特定的异常,因为您正在调用ex.InnerException.ToString()
。InnerException
属性并不总是填充(事实上,它通常不是,也不应该填充)
您的根本问题可能是网络服务帐户没有访问队列的权限(在本例中,从队列中读取)
下面是一些代码,可以帮助您在事件日志中获取实际错误:
catch(Exception ex)
{
Exception e = ex;
StringBuilder message = new StringBuilder();
while(e != null)
{
if(message.Length > 0) message.AppendLine("\nInnerException:");
message.AppendLine(e.ToString());
e = e.InnerException;
}
EventLogger.LogEvent(EventSource, EventLogType, "OnStart" + _lineFeed +
message.ToString());
}
请发布
异常的内容,包括堆栈跟踪。