title: Reading From a Text File in C#
body: <p>I have the following program that will send (output) information to a text file, but now I want to read (input) from the text file.  Any suggestions would be greatly appreciated. I have commented out a couple of things that "I think" I need to do; but I am not really certain how to proceed.</p>
  
  <pre><code>using System.Windows.Forms;
  using System.IO;
  
  namespace Input_Output
  {
      public partial class Grades : Form
      {
          private StreamWriter output;
  
          private StreamReader input;
  
  
          public Grades()
          {
              InitializeComponent();
          }
  
          private void label4_Click(object sender, EventArgs e)
          {
  
          }
  
          private void btnCreate_Click(object sender, EventArgs e)
          {
              btnEnter.Visible = true;
              btnClose.Visible = true;
              txtFirst.Visible = true;
              txtLast.Visible = true;
              lblFirst.Visible = true;
              lblLast.Visible = true;
              listBox1.Visible = true;
              lblStatus.Visible = true;
              lblGrade.Visible = true;
              lblCourse.Visible = true;
              cmbID.Visible = true;
              lblID.Visible = true;
              txtCourse.Visible = true;
              txtGrade.Visible = true;
              lblStatus.Visible = true;
  
              DialogResult result;
              string fileName;
              using (SaveFileDialog chooser = new SaveFileDialog())
              {
                  result = chooser.ShowDialog();
                  fileName = chooser.FileName;
              }
              output = new StreamWriter(fileName);
              btnCreate.Enabled = false;
              txtFirst.Visible = true;
              txtLast.Visible = true;
              lblFirst.Visible = true;
              lblLast.Visible = true;
              btnEnter.Visible = true;
              btnClose.Visible = true;
          }
  
  
          private void btnClose_Click(object sender, EventArgs e)
          {
              //Close button pushes information from the listbox in to the text file
  
              output.Close();
              lblStatus.ForeColor = Color.Red;
              lblStatus.Text = "Output File";
              btnCreate.Enabled = true;
              listBox1.Items.Clear();
              cmbID.Text = "";
          }
  
          private void btnEnter_Click(object sender, EventArgs e)
          {
              // Enter button sends information to the list box, a Message Box prompts user to check for accuracy.  
              //Close button pushes information to the Text file.
              string last = "";
              string first = "";
              string course = "";
              string grade = "";
  
              if (txtFirst.Text != "" &amp;&amp; txtLast.Text != "" &amp;&amp; txtCourse.Text != "")
              {
                  last = txtFirst.Text;
                  first = txtLast.Text;
                  course = txtCourse.Text;
                  grade = txtGrade.Text;
                  output.WriteLine (last + "\t"+ "\t" + first + ":"+ "\t" + cmbID.SelectedItem + "_" + course + "_" + grade );
  
                  listBox1.Items.Add(txtLast.Text + "," + txtFirst.Text + ":" + cmbID.SelectedItem + "-" + txtCourse.Text + "-" + txtGrade.Text);
                  lblStatus.ForeColor = Color.Navy;
                  lblStatus.Text = "Entry Saved";
                  txtFirst.Text = "";
                  txtLast.Text = "";
                  txtCourse.Text = "";
                  txtGrade.Text = "";
                  txtFirst.Focus();
              }
              else
              {     
                  lblStatus.ForeColor = Color.Red;
                  lblStatus.Text = "Empty text box or boxes";
              }
              MessageBox.Show("Please verify that the information is correct before proceeding");
          }
  
          private void btnExit_Click(object sender, EventArgs e)
          {
              Application.Exit();
          }
  
          private void Grades_Load(object sender, EventArgs e)
          {
  
          }
  
          private void button1_Click(object sender, EventArgs e)
          {
              DialogResult result;
              string fileName;
              using (OpenFileDialog chooser = new OpenFileDialog())
              {
                  result = chooser.ShowDialog();
                  fileName = chooser.FileName;
              }
              //while loop?
              //if variable is null, it's the end of the record
              //variable= !null 
              //txt read int variable TxtFile.Text += Rec + "\r\n";   while rec !=null;
          }
      }
  }
  </code></pre>