Write to a text file

Question

I am looking for a way to write to a text file in C#. I have created a form that has a textbox for firstname, lastname, phone number, date of birth. When a user hits the button I would like that info wrote out to a text file. The examples I have found don't really tell me how. So that's why I am asking on here.

Answer 1

The very simplest way is just to use File.WriteAllText. Build the text into a single string however you want to, then use

File.WriteAllText(filename, text);

Alternatively you can open a TextWriter on the file to do it bit by bit:

using (TextWriter writer = File.CreateText(filename)) // Or AppendText
{
    writer.WriteLine("First name: {0}", firstNameInput.Text);
    writer.WriteLine("Last name: {0}", lastNameInput.Text);
    writer.WriteLine("Phone number: {0}", phoneInput.Text);
    writer.WriteLine("Date of birth: {0}", birthInput.Text);
}

Note that you may want to be more cunning about the date of birth than just dumping the text directly from the user - you may want to validate it and write it in a standard format, for example.

Answer 2

Inside a ButtonClick or similar:

using (var writer = System.IO.File.CreateText(fileName))
{
    writer.WriteLine(firstNametextbox.Text);
    // other writes
}