♦ Using Textbox with newline

This will explain the code sample  how to use "for loop" and print out text with newline.

Figure 1. Output result screen.

We can use Textbox display some text into Textbox with newline. the i value is any variable we can put into below command.

<code c#>
      textBoxMultiLine.Text += "" + i + Environment.NewLine;
</code c#>

Example Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace forloop2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

       
        private void button1Run_Click(object sender, EventArgs e)
        {

            //Check valid , Is start field empty ?
            if (textBoxStart.Text.Trim() !="" && textBoxEnd.Text.Trim() !="")
            {
                // get values from start and stop 
                int start = int.Parse(textBoxStart.Text);
                int stop = int.Parse(textBoxEnd.Text);
                
                //check valid, is in 1-100 range allowed.
                if (start >= 0 && stop <= 100)
                {
                    //Start calculation with for loop command
                    for (int i = start; i <= stop; i++)
                    {
                        //Note: you must use operator [+= ""]
                        textBoxMultiLine.Text += "" + i + Environment.NewLine;
                    }

                } else 
                {
                    textBoxMultiLine.Text = "Out of range, Check...\r\n";
                }
            }
            else
            {
                textBoxMultiLine.Text = "Start or end value is empty.\r\n";
            }
            
            
        }

        private void button2Clear_Click(object sender, EventArgs e)
        {
            textBoxMultiLine.Text ="";
        }

        private void textBoxMultiLine_TextChanged(object sender, EventArgs e)
        {

        }

        
    }
}

In Textbox properties you must change its to multiline.

Figure 2: Textbox properties

Some part of code .... ..Form1.Designer.cs

...
...
...
// textBoxMultiLine
// 
this.textBoxMultiLine.Location = new System.Drawing.Point(231, 12);
this.textBoxMultiLine.Multiline = true;
this.textBoxMultiLine.Name = "textBoxMultiLine";
this.textBoxMultiLine.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
this.textBoxMultiLine.Size = new System.Drawing.Size(160, 111);
this.textBoxMultiLine.TabIndex = 8;
this.textBoxMultiLine.TextChanged += new System.EventHandler(this.textBoxMultiLine_TextChanged);
// 
...
...
...