Unable to read values from csv file

Change this line:

richTextBox1.Text = "Name: " + values[1] + "\nSurname: " + values[2] + "\nJob Role: " + values[3] + "\nSalary: £" + values[4]; 

to

richTextBox1.Text += "Name: " + values[1] + "\nSurname: " + values[2] + "\nJob Role: " + values[3] + "\nSalary: £" + values[4]; 

Alternatively, build the whole text first using a StringBuilder and assign it to richTextBox1.Text in one go.

If you are in the middle of the file this:

!reader.EndOfStream will be true so you have:

while (true || answer == idStr) => while (true) 

And it will go to the end of the file of course.

I think you want the following check:

while (!reader.EndOfStream && answer != idStr) 

As I understand you need only values from the line with the specified ID. You need to break your loop as you reached the correct ID.

 while (!reader.EndOfStream ) { var line = reader.ReadLine(); var values = line.Split(','); idStr = values[0]; if (answer == idStr) { richTextBox1.Text = "Name: " + values[1] + "\nSurname: " + values[2] + "\nJob Role: " + values[3] + "\nSalary: £" + values[4]; break; } } 

Side notes:

1) Reading (or writing) CVS files is not simple task by itself as it might appear. It is better to use a libraries like CsvHelper and A Fast CSV Reader

2) your code misses error handling: you might get empty "line", not all values might be set in this like (so, values[4], for example, will throw out of range exception, and etc.

Why not using:

 string idYouSearched = "2"; var encoding = Encoding.GetEncoding("iso-8859-1"); var csvLines = File.ReadAllLines(fileName,encoding); foreach (var line in csvLines ) { var values = line.Split(','); if(values[0].Contains(idYouSearched)) { richTextBox1.Text += "Name: " + values[1] + "\nSurname: " + values[2] + "\nJob Role: " + values[3] + "\nSalary: £" + values[4]; } } It`s much simpler and you not holding open stream when working with the UI.