Apply a calculation on all lines from a file

Question

I'm stuck on a problem, I can not execute my calculation on all lines of my text file. The calculation only applies to the first line. I want to see my result in richTextBox2.

Here is my code :

using (StreamReader sr1 = new StreamReader(fileName))
{
    while ((line = sr1.ReadLine()) != null)
    {
        commands = line.Split(' ');
        if ((commands.Length > 1) && (commands[1].Contains('X')))
        {
            double X = Convert.ToDouble(commands[1].Substring(1, commands[1].Length - 1).Replace(".", ""));
            double Y = Convert.ToDouble(commands[2].Substring(1, commands[2].Length - 1).Replace(".", ""));
            Un = ((X * 100) / 1.57) / 1000;
            Deux = ((Y * 100) / 1.57) / 1000;

            richTextBox2.Text = "VM " + "M1=" + Un.ToString(".0") + " M2=" + Deux.ToString(".0");
        }
    }
}

Answer 1

You are assigning to your richTextBox new text in each iteration instead of appending it. Try this.

richTextBox2.Text += "VM " + "M1=" + Un.ToString(".0") + " M2=" + Deux.ToString(".0");

It is better to first read file and then assign it to rictTextBox. Like this.

string fileData = "";
using (StreamReader sr = new StreamReader(fileName))
{
     fileData  = sr.ReadToEnd();
}

StringBuilder sb = new StringBuilder();
if (!String.IsNullOrEmptry(fileData))
{
   string[] splitedData = fileData.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries); // Suppose file has delimited by newline

   foreach (string line in splitedData)
   {
       commands = line.Split(' ');
       if ((commands.Length > 1) && (commands[1].Contains('X')))
       {
           double X = Convert.ToDouble(commands[1].Substring(1, commands[1].Length - 1).Replace(".", ""));
           double Y = Convert.ToDouble(commands[2].Substring(1, commands[2].Length - 1).Replace(".", ""));
           Un = ((X * 100) / 1.57) / 1000;
           Deux = ((Y * 100) / 1.57) / 1000;

          sb.AppendLine("VM " + "M1=" + Un.ToString(".0") + " M2=" + Deux.ToString(".0"));
       }
   }

   richTextBox2.Text = sb.ToString();
}