运算符“||"不能应用于“lambda 表达式"和“lambda 表达式"类型的操作数 [英] Operator '||' cannot be applied to operands of type 'lambda expression' and 'lambda expression'

问题描述

如何构造包含 OR 的 LINQ WHERE 子句?

How do i construct a LINQ WHERE clause that contains OR?

我有一个对象列表，我想返回那些匹配搜索条件的对象.

i have a list of objects, and i want to return those that match a search criteria.

包含的对象有很多属性，只要any符合条件，我就想返回:

The contained objects have many properties, and as long as any match the criteria, i want to return it:

IEnumerable<Item> list;
String keyword; 
...

var results = list.Where(
      (item => item.Name.Contains(keyword, StringComparison.CurrentCultureIgnoreCase))
      ||
      (item => item.Description.Contains(keyword, StringComparison.CurrentCultureIgnoreCase))
      ||
      (item => item.Description.Contains(keyword, StringComparison.CurrentCultureIgnoreCase))
      ||
      (item => item.ItemType.Contains(keyword, StringComparison.CurrentCultureIgnoreCase))
      ||
      (item => item.ItemID.ToString().StartsWith(keyword, StringComparison.CurrentCultureIgnoreCase))
      ||
      (items => items.Value.ToString().StartsWith(keyword, StringComparison.CurrentCultureIgnoreCase))
);

但是编译失败:

运算符'||'不能应用于lambda 表达式"和lambda 表达式"类型的操作数

Operator '||' cannot be applied to operands of type 'lambda expression' and 'lambda expression'

如何构造包含 OR 的 LINQ WHERE 子句?

How do i construct a LINQ WHERE clause that contains OR?

• LINQ where or filter c#

推荐答案

只需在同一个 lambda 表达式中进行所有测试...

Just do all your tests in the same lambda expression...

IEnumerable<Item> list;
String keyword; 
...

var results = list.Where(
      item => item.Name.Contains(keyword, StringComparison.CurrentCultureIgnoreCase)
      || item.Description.Contains(keyword, StringComparison.CurrentCultureIgnoreCase)
      || item.Description.Contains(keyword, StringComparison.CurrentCultureIgnoreCase)
      || item.ItemType.Contains(keyword, StringComparison.CurrentCultureIgnoreCase)
      || item.ItemID.ToString().StartsWith(keyword, StringComparison.CurrentCultureIgnoreCase)
      || items.Value.ToString().StartsWith(keyword, StringComparison.CurrentCultureIgnoreCase)
);

这篇关于运算符“||"不能应用于“lambda 表达式"和“lambda 表达式"类型的操作数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！