如何在C＃中的lambda表达式中应用多项条件以及更高的条件 [英] How to apply mulitple criteria in lambda expression in c# along with greater then criteria

问题描述

我在继续我的问题上一个问题。在我的最后一个问题中，@ p.s.w.g提供了我想要的确切解决方案。现在我想到另一种情况，假设我们需要先搜索个更大的字符，然后搜索4 ，然后再做什么。

I am Continuing my question Previous Question . In my last question @p.s.w.g gives exact solution as i want . Now another situation comes into my mind that suppose we need to search greater then 4 in a condition then what will we do .

详细信息

在我最后一个问题中，我说标准将达到 1-4 ，假设我们包含更多条件，并给用户一个选择 4 + 的选项，我们将返回所有数据其中卧室大于4。在这种情况下我们将做什么。

In my last question i said the criteria will goes up to 1-4 , Suppose we include more criteria and give user a option to select 4+ and we will return all data where Bedroom is greater then four . What we will do in this case .

假设我在我的过滤器变量 var filter = 1,4,4 +;

Suppose i got this in my filter variable var filter = "1,4,4+";

在这种情况下，我们应该向用户返回所有列表，其中卧室为 1 或 4 或大于4 。

In this condition we should return user all Listings where Bedrooms are either 1 or 4 or Greater then 4.

我尝试过的事情

var bedCriteria = "1,4,4+";
bedCriteria  = bedCriteria .Split(',').ToList();
bool isGreaterThenCriteria = bedCriteria.Contains("4+");
if (isGreaterThenCriteria)
{
     query = query.Where(l => l.Place.Bedroom > 4);
     bedCriteria.Remove("4+");
}

var minBeds = bedCriteria.Select(int.Parse);
query = query.Where(l => minBeds.Contains(l.Place.Bedroom.Value));

推荐答案

在我之前的回答中，假设您有以下内容：

Extending on my previous answer, suppose you have this:

var minBeds = "1,2,4".Split(',').Select(int.Parse);
query = query.Where(l => minBeds.Contains(l.Place.Bedroom));

您可以将其更改为...

You can change this to...

var minBedStrings = "1,4,4+".Split(',');
var has4plus = minBedStrings.Contains("4+");
var minBeds = minBedStrings.Where(x => x != "4+").Select(int.Parse);
query = query.Where(l => minBeds.Contains(l.Place.Bedroom) || 
                         (has4plus && l.Place.Bedroom > 4));

如果您要处理 5 + 或 6 + ...

If you want to handle something like "5+" or "6+" as well...

var minBedStrings = "1,4,4+".Split(',');
var nplus = minBedStrings.Where(x => x.Last() == '+')
                         .Select(x => (int?)int.Parse(x.Substring(0, x.Length - 1))
                         .OrderBy(x => x)
                         .FirstOrDefault();
var minBeds = minBedStrings.Where(x => x.Last() != '+')
                           .Select(int.Parse);
query = query.Where(l => minBeds.Contains(l.Place.Bedroom) || 
                         (nplus.HasValue && l.Place.Bedroom > nplus.Value));

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