Open text file, loop through contents and check against

Question

So I have a generic number check that I am trying to implement:

    public static bool isNumberValid(string Number)
    {
    }

And I want to

Answer 1

You could try this to keep with the pattern you were initially following...

private void button1_Click(object sender, EventArgs e)
{
    DialogResult result = openFileDialog1.ShowDialog(); // Show the dialog.
    if (result == DialogResult.OK) // Test result.
    {
        string file = openFileDialog1.FileName;
        try
        {
            using (var reader = new StreamReader(file))
            {
                using (var writer = new StreamWriter("results.txt"))
                {
                    string currentNumber;
                    while ((currentNumber = reader.ReadLine()) != null)
                    {
                        if (IsNumberValid(currentNumber))
                            writer.WriteLine(String.Format("{0} true", currentNumber));
                    }
                }
            }
        }

        catch (IOException)
        {
        }
    }
}

public bool IsNumberValid(string number)
{
    //Whatever code you use to check your number
}