长？不包含扩展方法的最佳扩展重载方法querable.conatains< long？ > [英] Long? Does not contains defintion for extension method best extension overload method querable.conatains<long? >

问题描述

错误：

多长？不包含扩展方法的定义最佳扩展重载方法Querable.conatains< long？>

Error:
long? does not contains defintion for extension method best extension overload method Querable.conatains<long?>

var _OrderResponse = (await _tagProvider.GetBaseOrderAsync(new GetBaseOrderRequest() { })).BaseObjects.Where(b => b.CustomerId.Contains(request.customerId)).ToList();

请帮帮我。

谢谢你



我的尝试：



错误：

多长？不包含扩展方法的定义最佳扩展重载方法Querable.conatains< long？>

Please help me.
Thank u

What I have tried:

Error:
long? does not contains defintion for extension method best extension overload method Querable.conatains<long?>

var _OrderResponse = (await _tagProvider.GetBaseOrderAsync(new GetBaseOrderRequest() { })).BaseObjects.Where(b => b.CustomerId.Contains(request.customerId)).ToList();

推荐答案

包含（）仅适用于字符串而非数字。



尝试 b => b.CustomerId == request.customerId

Contains() only applies to strings not numbers.

Try b => b.CustomerId == request.customerId

包含适用于集合和字符串（字符集合）。

A long不能直接通过 foreach 或使用Linq方法迭代，因为它不是集合并且不实现IEnumerable接口： Enumerable.Contains Method（System.Linq）| Microsoft Docs [ ^ ]

Contains applies to collections and strings (which are collections of characters).
A long cannot be iterated over either directly via a foreach or by using Linq methods as it is not a collection and does not implement the IEnumerable interface: Enumerable.Contains Method (System.Linq) | Microsoft Docs[^]

这篇关于长？不包含扩展方法的最佳扩展重载方法querable.conatains&lt; long？ &GT;的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！