This document provides code to write the text from a multiline textbox to a text file in C#. It includes code to split the textbox text into an array by line, loop through the array, write each line to the text file while removing whitespace, and close the file writer. The code uses StreamWriter to open a file for writing, WriteLine to write each array element on its own line, and Close to finish writing and close the file.

1. Write text file in C#
This article will guide you get line of multiline textbox and write to txt file.
1: using System;
2: using System.Collections.Generic;
3: using System.ComponentModel;
4: using System.Data;
5: using System.Drawing;
6: using System.Linq;
7: using System.Text;
8: using System.Windows.Forms;
9: using System.IO;
10:
11: namespace Write_text_file
12: {
13: public partial class Form1 : Form
14: {
15: public Form1()
16: {
17: InitializeComponent();
18: }
19:
20: private void button1_Click(object sender, EventArgs e)
21: {
22: TextWriter tw = new StreamWriter("C:test.txt");
23: string[] mystring = textBox1.Text.Split(new char[] { 'n' });
24: for (int i = 0; i < mystring.Length; i++)
25: {
26: tw.WriteLine(mystring[i].ToString().Trim());
27: }
28: tw.Close();
29: }
30: }
31: }
Download Source Code