Question

我有一个文本文件，其格式如下

Number,Name,Age

我想在此文本文件的第一列读取“数字”到数组中以查找重复项。这是我尝试在文件中阅读的两种方式。

 string[]  account = File.ReadAllLines(path);
 string readtext = File.ReadAllText(path);

但是每当我尝试将数组拆分为刚刚得到第一个逗号左边的什么时，我就失败了。有什么想法吗？谢谢。

Answer 1

您需要明确拆分数据以访问其各个部分。您的程序如何能够决定用逗号分隔它？

访问我想到的数字的最简单方法是这样的：

var lines = File.ReadAllLines(path);
var firstLine = lines[0];
var fields = firstLine.Split(',');
var number = fields[0]; // Voilla!

您可以通过将数字解析为int或其他数字类型（如果它确实是数字）来进一步发展。另一方面，如果您只是想测试唯一性，那么这不是必需的。

Answer 2

如果您想要根据Number：

的所有重复行

var numDuplicates = File.ReadLines(path)
    .Select(l => l.Trim().Split(','))
    .Where(arr => arr.Length >= 3)
    .Select(arr => new { 
        Number = arr[0].Trim(),
        Name   = arr[1].Trim(),
        Age    = arr[2].Trim()
    })
    .GroupBy(x => x.Number)
    .Where(g => g.Count() > 1);

foreach(var dupNumGroup in numDuplicates)
    Console.WriteLine("Number:{0} Names:{1} Ages:{2}"
        , dupNumGroup.Key
        , string.Join(",", dupNumGroup.Select(x => x.Name))
        , string.Join(",", dupNumGroup.Select(x => x.Age)));

Answer 3

如果您正在寻找专门针对string.split解决方案，这是一个非常简单的方法来完成您所寻找的工作：

List<int> importedNumbers = new List<int>();
// Read our file in to an array of strings
var fileContents = System.IO.File.ReadAllLines(path);
// Iterate over the strings and split them in to their respective columns
foreach (string line in fileContents)
{
      var fields = line.Split(',');
      if (fields.Count() < 3)
          throw new Exception("We need at least 3 fields per line."); // You would REALLY do something else here...
      // You would probably want to be more careful about your int parsing... (use TryParse)
      var number = int.Parse(fields[0]);
      var name = fields[1];
      var age = int.Parse(fields[2]);
      // if we already imported this number, continue on to the next record
      if (importedNumbers.Contains(number))
          continue;  // You might also update the existing record at this point instead of just skipping...
      importedNumbers.Add(number); // Keep track of numbers we have imported
}

读取文本文件并在c＃中用逗号分割

3 个答案: