FileInfo的>二列表℃之间的差异; [英] Difference between two List<FileInfo>

问题描述

我可以用一个花哨的LINQ查询返回列表< FileInfo的> ，通过传递它的方法（列表< FileInfo的> oldList，清单< FileInfo的> newList ），看到有什么区别有两个列表之间

Can I use a fancy LINQ query to return a List<FileInfo>, by passing it in a method (List<FileInfo> oldList, List<FileInfo> newList), and seeing what differences there are between the two lists?

基本上，我想要得到的任何名单文件添加到newList，这是不是在oldList用。

Basically, I want to get a list of any files added to newList, that were not available in oldList.

推荐答案

给定一个的IEqualityComparer 为的FileInfo 如下图所示：

Given an IEqualityComparer for FileInfo shown below:

public class FileInfoEqualityComparer : IEqualityComparer<FileInfo>
{
    public bool Equals(FileInfo x, FileInfo y)
    {
        return x.FullName.Equals(y.FullName);
    }

    public int GetHashCode(FileInfo obj)
    {
        return obj.FullName.GetHashCode();
    }
}

您可以使用下面的代码来找到两者之间的区别列表：

You can use following code to find the difference between two lists:

var allItems = newList.Union(oldList);
var commonItems = newList.Intersect(oldList);
var difference = allItems.Except(commonItems, new FileInfoEqualityComparer());

要找到添加到 newList 列表项，使用下面的代码：

To find items added to newList list, use following code:

var addedItems = newList.Except(oldList, new FileInfoEqualityComparer());

这篇关于FileInfo的>二列表℃之间的差异;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！