过滤的LINQ除了在性能 [英] Filter Linq EXCEPT on properties

问题描述

这可能看起来很傻，但所有的例子，我发现在使用LINQ使用EXCEPT两个列表或仅字符串或整数数组和过滤他们根据比赛中，例如：

This may seem silly, but all the examples I've found for using EXCEPT in linq use two lists or arrays of only strings or integers and filters them based on the matches, for example:

VAR排除= users.Except（匹配）;

我想用排除让我的code简短，但似乎无法找出如何做到以下几点：

I want to use exclude to keep my code short and simple, but can't seem to find out how to do the following:

class AppMeta
{
  public int Id {get;set;}
}

var excludedAppIds = new List<int> {2, 3, 5, 6};
var unfilteredApps = new List<AppMeta>
                         {
                           new AppMeta {Id = 1}
                           new AppMeta {Id = 2}
                           new AppMeta {Id = 3}
                           new AppMeta {Id = 4}
                           new AppMeta {Id = 5}
                         }

我如何获得AppMeta的一个列表上excludedAppIds过滤器？

How do I get a list of AppMeta back that filters on excludedAppIds?

推荐答案

尝试一个简单的查询在哪里

Try a simple where query

var filtered = unfilteredApps.Where(i => !excludedAppIds.Contains(i.Id)); 

除了该方法采用平等，你的列表包含不同类型的对象，所以没有它们包含将相等的物品！

The except method uses equality, your lists contain objects of different types, so none of the items they contain will be equal!

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