使用linq在通用列表中进行部分搜索 [英] Partial search in generic list using linq

问题描述

大家好，我有一个字符串列表，其中包含我想在程序中跳过的文件夹名称，列表如下所示

Hi all, I have a string list containing folder names I want to skip in my program, the list is like the one shown below

List<String> IgnoreFolders = new List<String>();
IgnoreFolders.Add("SYNC ISSUES");
IgnoreFolders.Add("TRASH");
IgnoreFolders.Add("JUNK");

在我的程序中，我想检查我正在处理的文件夹名称是否是这个列表（或部分）我得到的是这个（它有效，但我确定有一个更清洁的方式）如果文件夹名称是SYNC ISSUES1或SYNC ISSUES2等我也想将它们排除在列表中的包含不起作用

In my program I want to check if a folder name that I'm processing is this list( or partially ) What I've got is this ( it works but I'm sure there's a cleaner way ) If the folder name is "SYNC ISSUES1" or "SYNC ISSUES2" etc I want to exclude them also so Contains on the List won't work

bool IgnoreFolder(Folder folder)
{
    String FolderName = folder.Name.ToUpper();
    bool RetVal = false;
       
    foreach(String s in IgnoreFolders)
    {
      if (FolderName.StartsWith(s.ToUpper()))
      {
          RetVal = true;
          break;
      }
    }
    return RetVal;
}

希望这是有道理的。



< b>我尝试了什么：



上面显示的代码使用Linq

Hope this makes sense.

What I have tried:

The code shown above Partial search in generic List using Linq

推荐答案

如果你的目标是获取一个列表（在这种情况下，是FileNames）并快速确定哪些项目（在这种情况下，字符串）可以根据某些标准排除（在这种情况下，一组中的匹配）字符串），考虑这样的事情：

If your goal is take a list (in this case, of FileNames) and quickly determine which items (in this case, strings) can be excluded based on some criterion (in this case, a match in a set of strings), consider something like this:

using System;
using System.Collections.Generic;
using System.Linq;

IgnoreFolders = new List<string>
{
    "SYNC ISSUES",
    "TRASH",
    "JUNK",
};

TestNames = new List<string>
{
    "SYNC ISSUES1",
    "SYNC ISSUES2",
    "sometrash", "trash more", "my trash is",
    "myJUNK", "junkYOUR", "JUNKJUNKJUNK",
    "good name 1", "june bug good name",
    "tras hot good name", "jun k tras h"
};

var FileNamesToIgnore = TestNames
    .Where(name => IgnoreFolders
        .Any(itm => name.ToUpper()
            .Contains(itm)));

var GoodToGoFileNames = TestNames.Except(FileNamesToIgnore);

您可以轻松地将此代码包装在一个函数中;为了重复使用，我建议在该函数中有一个布尔标志，用于确定是否应忽略letter-case（如示例中所示）。

You could easily wrap this code in a Function; for re-use, I'd suggest having a boolean flag in that function that determined whether letter-case should be ignored (as in the example, here).

bool IgnoreFolder(Folder folder)
{
    String folderName = folder.Name.ToLower();

    return IgnoreFolders.Any(x => folderName.Contains(x.ToLower()));
}

这将是LINQified版本：

This would be the LINQified version:

bool IgnoreFolder(Folder folder)
{
    String FolderName = folder.Name.ToUpper();

    return IgnoreFolders.Any(ign => FolderName.StartsWith(ign.ToUpper());
}

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