c# - 有没有办法简化这个 linq

Question

我有 2 个 bool 标志，需要相应地过滤我的集合。必须有一种更清洁的方法来做到这一点。如果有人能指出我正确的方向，我将不胜感激。谢谢。

var _filteredEvents = from ev in _events 
                      select ev;
if (!queueEmail) // don't queue email
{
    if (!queueTextMessaging) // don't queue textmessaging
    {
        _filteredEvents = from ev in _events
                              where ev.QueueTypeEnumText != QueueType.TextMessage.ToString() 
                                && ev.QueueTypeEnumText !=QueueType.Email.ToString()
                              select ev;
    }
    else
    {
         _filteredEvents = from ev in _events
                              where ev.QueueTypeEnumText != QueueType.Email.ToString()
                              select ev;
    }
}
else //queue email
{
    if (!queueTextMessaging) //don't queue textmessaging
    {
        _filteredEvents = from ev in _events
                          where ev.QueueTypeEnumText != QueueType.TextMessage.ToString()
                          select ev;
    }
}

Answer 1

由于 LINQ 使用延迟执行，您只需将 Where() 扩展更改为您的对象，并在您进行时重新分配它:

var _filteredEvents = _events; 
if (!queueEmail)
     _filteredEvents =  _filteredEvents.Where(ev => ev.QueueTypeEnumText != QueueType.Email.ToString());
if (!queueTextMessaging)
     _filteredEvents =  _filteredEvents.Where(ev => ev.QueueTypeEnumText != QueueType.TextMessage.ToString());