ArgumentNullException: 值不能为 null。
参数名: source
StackTrace:
   在 System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   在 Ci3RULiH5a8Cgg0fIS5.UIy1pYiDsLcf2l4joSP.Y2cvgdXgXh5(Point  )
   在 Ci3RULiH5a8Cgg0fIS5.UIy1pYiDsLcf2l4joSP.rNhvgDojDlE()
   在 Ci3RULiH5a8Cgg0fIS5.UIy1pYiDsLcf2l4joSP.zk9vg5W6Gtb()
   在 System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   在 System.Threading.ThreadHelper.ThreadStart()