在C#中的对象列表中使用RemoveAll#不删除项

我有一个邮件列表。我想浏览列表并执行以下操作：

如果SenderID=100，则将ShowInSenderInbox和ShowInSenderOutbox的值设置为零

如果ReceiverID=100，则将ShowInReceiverInbox值设置为零。 一旦满足上述两个条件，我想检查以下内容：

如果ShowInSenderInbox==0&&ShowInSenderOutbox==0&&ShowInReceiveInbox==0 然后从列表中删除此项

目前，我的代码将ShowInSenderInbox、ShowInSenderOutbox和ShowInReceiveInbox的值相应地设置为零。但是，它不会从列表中删除与条件3匹配的项

以下是完整的代码：

public class Message
{
   public int MessageID { get; set; }
   public int SenderID { get; set; }
   public int ReceiverID { get; set; }
   public int ShowInSenderInbox { get; set; }
   public int ShowInSenderOutbox { get; set; }
   public int ShowInReceiverInbox { get; set; }
}

public bool GetItem(Message I)
{           
   if (I.SenderID == 100)
   {
      I.ShowInSenderInbox = 0;
      I.ShowInSenderOutbox = 0;
   }
   else if (I.ReceiverID == 100)
   {
      I.ShowInReceiverInbox = 0;
   }

   if (I.ShowInSenderInbox == 0 && I.ShowInSenderOutbox == 0 && I.ShowInReceiverInbox == 0)
   {
      return true;
   }
   else
   {
      return false;
   }                             
}


List<Message> messages = new List<Message>() {
    new Message { MessageID=1, SenderID=100, ReceiverID=200, ShowInSenderInbox=1, ShowInSenderOutbox=1, ShowInReceiverInbox=1 },
    new Message { MessageID=2, SenderID=101, ReceiverID=300, ShowInSenderInbox=1, ShowInSenderOutbox=1, ShowInReceiverInbox=1 },
    new Message { MessageID=3, SenderID=102, ReceiverID=100, ShowInSenderInbox=1, ShowInSenderOutbox=0, ShowInReceiverInbox=0 },
    new Message { MessageID=4, SenderID=100, ReceiverID=101, ShowInSenderInbox=0, ShowInSenderOutbox=1, ShowInReceiverInbox=0 },
    new Message { MessageID=5, SenderID=200, ReceiverID=300, ShowInSenderInbox=1, ShowInSenderOutbox=0, ShowInReceiverInbox=0 },
    new Message { MessageID=9, SenderID=100, ReceiverID=400, ShowInSenderInbox=1, ShowInSenderOutbox=1, ShowInReceiverInbox=1 },
    new Message { MessageID=11, SenderID=400, ReceiverID=100, ShowInSenderInbox=1, ShowInSenderOutbox=1, ShowInReceiverInbox=0 },
    new Message { MessageID=21, SenderID=80, ReceiverID=150, ShowInSenderInbox=1, ShowInSenderOutbox=0, ShowInReceiverInbox=1 },
    new Message { MessageID=23, SenderID=100, ReceiverID=300, ShowInSenderInbox=1, ShowInSenderOutbox=1, ShowInReceiverInbox=0 },
    new Message { MessageID=28, SenderID=50, ReceiverID=90, ShowInSenderInbox=1, ShowInSenderOutbox=0, ShowInReceiverInbox=1 },
    new Message { MessageID=29, SenderID=100, ReceiverID=900, ShowInSenderInbox=1, ShowInSenderOutbox=1, ShowInReceiverInbox=1 },
    new Message { MessageID=22, SenderID=500, ReceiverID=900, ShowInSenderInbox=0, ShowInSenderOutbox=0, ShowInReceiverInbox=0 },
    new Message { MessageID=39, SenderID=409, ReceiverID=500, ShowInSenderInbox=0, ShowInSenderOutbox=0, ShowInReceiverInbox=0 },
    new Message { MessageID=41, SenderID=105, ReceiverID=900, ShowInSenderInbox=0, ShowInSenderOutbox=0, ShowInReceiverInbox=0 }
 };

( from item in messages
  where item.SenderID == 100 || item.ReceiverID == 100
  select item )
               .ToList()
               .RemoveAll( I => GetItem(I) );

公共类消息
{
public int MessageID{get；set；}
public int SenderID{get；set；}
public int ReceiverID{get；set；}
public int ShowInSenderInbox{get；set；}
public int ShowInSenderOutbox{get；set；}
public int ShowInReceiverInbox{get；set；}
}
公共bool GetItem（消息一）
{           
如果（I.SenderID==100）
{
I.ShowInSenderInbox=0；
I.ShowInSenderOutbox=0；
}
否则，如果（I.接收方==100）
{
I.ShowInReceiverInbox=0；
}
如果（I.ShowInSenderInbox==0&&I.ShowInSenderOutbox==0&&I.ShowInReceiverInbox==0）
{
返回true；
}
其他的
{
返回false；
}                             
}
列表消息=新列表（）{
新邮件{MessageID=1，SenderID=100，ReceiverID=200，ShowInSenderInbox=1，ShowInSenderOutbox=1，ShowInReceiverInbox=1}，
新邮件{MessageID=2，SenderID=101，ReceiverID=300，ShowInSenderInbox=1，ShowInSenderOutbox=1，ShowInReceiverInbox=1}，
新邮件{MessageID=3，SenderID=102，ReceiverID=100，ShowInSenderInbox=1，ShowInSenderOutbox=0，ShowInReceiverInbox=0}，
新邮件{MessageID=4，SenderID=100，ReceiverID=101，ShowInSenderInbox=0，ShowInSenderOutbox=1，ShowInReceiverInbox=0}，
新邮件{MessageID=5，SenderID=200，ReceiverID=300，ShowInSenderInbox=1，ShowInSenderOutbox=0，ShowInReceiverInbox=0}，
新邮件{MessageID=9，SenderID=100，ReceiverID=400，ShowInSenderInbox=1，ShowInSenderOutbox=1，ShowInReceiverInbox=1}，
新邮件{MessageID=11，SenderID=400，ReceiverID=100，ShowInSenderInbox=1，ShowInSenderOutbox=1，ShowInReceiverInbox=0}，
新邮件{MessageID=21，SenderID=80，ReceiverID=150，ShowInSenderInbox=1，ShowInSenderOutbox=0，ShowInReceiverInbox=1}，
新邮件{MessageID=23，SenderID=100，ReceiverID=300，ShowInSenderInbox=1，ShowInSenderOutbox=1，ShowInReceiverInbox=0}，
新邮件{MessageID=28，SenderID=50，ReceiverID=90，ShowInSenderInbox=1，ShowInSenderOutbox=0，ShowInReceiverInbox=1}，
新邮件{MessageID=29，SenderID=100，ReceiverID=900，ShowInSenderInbox=1，ShowInSenderOutbox=1，ShowInReceiverInbox=1}，
新邮件{MessageID=22，SenderID=500，ReceiverID=900，ShowInSenderInbox=0，ShowInSenderOutbox=0，ShowInReceiverInbox=0}，
新邮件{MessageID=39，SenderID=409，ReceiverID=500，ShowInSenderInbox=0，ShowInSenderOutbox=0，ShowInReceiverInbox=0}，
新邮件{MessageID=41，SenderID=105，ReceiverID=900，ShowInSenderInbox=0，ShowInSenderOutbox=0，ShowInReceiverInbox=0}
};
（来自消息中的项目）
其中item.SenderID==100 | | item.ReceiverID==100
选择项目）
托利斯先生（）
.RemoveAll（I=>GetItem（I））；

---

只需再添加这一行：

messages.RemoveAll(i => i.ShowInSenderInbox == 0 && i.ShowInSenderOutbox == 0 && i.ShowInReceiverInbox == 0);

---

您不是在修改原始列表，而是（可能）在修改一个完全不同的列表。满足上述两个条件是什么意思？哪两个条件？谢谢杰夫和格兰特。谢谢@Koder101。我会的。