How to store text file line by line into temporary list after specific text

Question

I would like to store line by line from the text file after read it. However, the text that store into the temporary list must be after the ": ".

Below is the example of content in my text file:

Name: Johny
Age: 18
Favourite: Basketball, Food

I would like to store Johny as list[0], 18 as list[1], and etc. For the Favourite, it should be store separately such as Basketball as list[2] and Food as list[3] and etc. This is because I need to place it back to different textBox afterward.

Below is my example code:

private void storeDataList()
    {
        OpenFileDialog ofd = new OpenFileDialog();
        ofd.DefaultExt = ".txt";
        ofd.Filter = "Text Document (*.txt) | *.txt";
        string filename = ofd.FileName;
        string line = "";
        if (ofd.ShowDialog() == true)
        {
            StreamReader sr = new StreamReader(ofd.FileName);
            while (line != null)
            {
                for (int i = 0; i < 10; i++)
                {
                    List<string> elements = new List<string>();
                    string readText = File.ReadAllText(filename);
                    i = readText.LastIndexOf(": ");
                    elements.Add[i];
                }
            }
            sr.Close();
            detailsTextBox.Text = File.ReadAllText(filename);
        }
    }

Use `File.ReadAllLines` to read all lines from a text file. Use `string.Split` to split strings into substrings at specific separator characters. — Clemens, Dec 01 '20 at 09:42

score 1 · Answer 1 · answered Dec 01 '20 at 09:46

1

Here's a one liner with LINQ that reads the file into lines, split the lines on : and takes what's after, then splits that on , for further granularity:

var output = File.ReadAllLines(filename).SelectMany(l => l.Split(':')[1].Split(',').Select(s => s.Trim());

Which outputs a list of: Johny, 18, Basketball, Food.

answered Dec 01 '20 at 09:46

Haytam

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Just do `.ToList()` at the end, and it'll become a `List`. – Haytam Dec 01 '20 at 09:49

score 0 · Accepted Answer · answered Dec 01 '20 at 10:50

You can:

read it line by line
separate the fields and it's valued by splitting it with : delimiter
check the line every three-line
split the favorite value by comma delimiter ,

clean the value with trim to remove whitespaces

  private void storeDataList()
  {
      OpenFileDialog ofd = new OpenFileDialog();
      ofd.DefaultExt = ".txt";
      ofd.Filter = "Text Document (*.txt) | *.txt";
      string filename = ofd.FileName;
      string line = "";
      if (ofd.ShowDialog() == true)
      {
          List<string> elements = new List<string>();

          using (var reader = new StreamReader(ofd.FileName))
          {
              int rowNumber = 1;

              //Dynamically stop the loop until the end of the stream
              while (!reader.EndOfStream)
              {
                  //Split to separate field name and values
                  var textLine = reader.ReadLine().Split(':');

                  //Since favorite fields are in multiples of three, we re-split the value by comma every three line
                  if (rowNumber % 3 == 0)
                  {
                      var favouriteArr = textLine[1].Split(',');

                      for (int i = 0; i < favouriteArr.Length; i++)
                      {
                          //trim to clean whitespace
                          elements.Add(favouriteArr[i].Trim());
                      }
                  }
                  else
                  {
                      elements.Add(textLine[1].Trim());
                  }
                  rowNumber++;
              }
          }

          // # just a new delimiter to print the elements in a text box
          detailsTextBox.Text = string.Join('#', elements);
      }
  }

How to store text file line by line into temporary list after specific text

2 Answers2