C# 并排合并两个或多个文本文件 [英] C# Merging Two or more Text Files side by side

问题描述

using (StreamWriter writer = File.CreateText(FinishedFile))
{
    int lineNum = 0;
    while (lineNum < FilesLineCount.Min())
    {
        for (int i = 0; i <= FilesToMerge.Count() - 1; i++)
        {
            if (i != FilesToMerge.Count() - 1)
            {
                var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1);
                string CurrentLine = string.Join("", CurrentFile);
                writer.Write(CurrentLine + ",");
            }
            else
            {
                var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1);
                string CurrentLine = string.Join("", CurrentFile);
                writer.Write(CurrentLine + "\n");
            }
        }
        lineNum++;
    }
}

我目前这样做的方式太慢了.我正在合并每行超过 50k 行的文件，其中包含不同数量的数据.

The current way i am doing this is just too slow. I am merging files that are each 50k+ lines long with various amounts of data.

例如:档案1
1
2
3
4

for ex: File 1
1
2
3
4

文件 2
4
3
2
1

File 2
4
3
2
1

我需要这个合并成第三个文件
文件3
1,4
2,3
3,2
4,1

P.S.用户可以从任何位置选择任意数量的文件.
感谢您的帮助.

i need this to merge into being a third file
File 3
1,4
2,3
3,2
4,1

P.S. The user can pick as many files as they want from any locations.
Thanks for the help.

推荐答案

你的方法很慢，因为 Skip 和 Take 在循环中.

You approach is slow because of the Skip and Take in the loops.

您可以使用字典来收集所有行索引的行:

You could use a dictionary to collect all line-index' lines:

string[] allFileLocationsToMerge = { "filepath1", "filepath2", "..." };
var mergedLists = new Dictionary<int, List<string>>();
foreach (string file in allFileLocationsToMerge)
{
    string[] allLines = File.ReadAllLines(file);
    for (int lineIndex = 0; lineIndex < allLines.Length; lineIndex++)
    {
        bool indexKnown = mergedLists.TryGetValue(lineIndex, out List<string> allLinesAtIndex);
        if (!indexKnown)
            allLinesAtIndex = new List<string>();
        allLinesAtIndex.Add(allLines[lineIndex]);
        mergedLists[lineIndex] = allLinesAtIndex;
    }
}

IEnumerable<string> mergeLines = mergedLists.Values.Select(list => string.Join(",", list));
File.WriteAllLines("targetPath", mergeLines);

这篇关于C# 并排合并两个或多个文本文件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！