Linq-Where发生短路

问题描述

我在Linq-Where方法中遇到问题.我在where子句中得到了NullReferenceException，这不会发生，因为C#应该使用短路功能，并且第二个操作不能执行:

I have a problem in a Linq-Where method. I get a NullReferenceException in a where clause, which should not happen because C# should use short-circuiting and the second operations hould not be executed:

如果Item为null，则不应调用Item.State == ...，因为条件已经为真(短路).

If Item is null, Item.State == ... should not be called, because the condition is already true (short-circuiting).

但是，在这种情况下，短路似乎不起作用.

But it seems, that short-circuiting does not working in this case.

其他人有没有解决过这个问题?谢谢！

Does anyone else had and solved this problem? Thank you!

修改:最后，connectionList不应包含任何空值和断开的连接.

Edit:In the end, the connectionList should not contains any null-values and no broken connections.

推荐答案

在查询数据库时，这是常见问题.即，将短路行为转换为数据库，不会像您期望的那样工作.您可以阅读有关这种行为的更多信息: (或)使用C#

This is common problem, when querying against databases. Namely, translating short-circuiting behavior against databases, don't work the way as you would expect. You can read more about such behavior: The || (or) Operator in Linq with C#

您可以尝试以下方法:

connectionList.RemoveRange(connectionList.Where(x => x==null));
connectionList.SaveChanges();
connectionList.RemoveRange(connectionList.Where(x => x.Item==BrokenState));

只是看看它是否有效.

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