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 WindowsFormsApplication1

{

public partial class Form1 : Form

{

private List<TextBox> inputTextBoxes;

public Form1()

{

InitializeComponent();

this.AutoSizeMode = AutoSizeMode.GrowAndShrink;

this.AutoSize = true;

this.Padding = new Padding(0, 0, 20, 20);

this.StartPosition = FormStartPosition.CenterScreen;

}

private void button1_Click(object sender, EventArgs e)

{

//Get the number of input text boxes to generate

int inputNumber = Int32.Parse(textBoxInput.Text);

//Initialize list of input text boxes

inputTextBoxes = new List<TextBox>();

//Generate labels and text boxes

for (int i = 1; i <= inputNumber; i++)

{

//Create a new label and text box

Label labelInput = new Label();

TextBox textBoxNewInput = new TextBox();

//Initialize label's property

labelInput.Text = "Input " + i;

labelInput.Location = new Point(30, textBoxInput.Bottom + (i * 30));

labelInput.AutoSize = true;

//Initialize textBoxes Property

textBoxNewInput.Location = new Point(labelInput.Width, labelInput.Top - 3);

//Add the newly created text box to the list of input text boxes

inputTextBoxes.Add(textBoxNewInput);

//Add the labels and text box to the form

this.Controls.Add(labelInput);

this.Controls.Add(textBoxNewInput);

}

//Create an Add button

Button buttonAdd = new Button();

//Initialize Properties

buttonAdd.Text = "Add";

//Make the button show up in the middle of the form and right below the last input box

buttonAdd.Location = new Point(this.Width / 2 - buttonAdd.Width / 2,

inputTextBoxes[inputTextBoxes.Count - 1].Bottom + 20);

//Add an event handler to the button's click event

buttonAdd.Click += new EventHandler(buttonAdd_Click);

//Add the button to the form

this.Controls.Add(buttonAdd);

//Center the form to the screen

this.CenterToScreen();

}

void buttonAdd_Click(object sender, EventArgs e)

{

int sum = 0;

foreach (TextBox inputBox in inputTextBoxes)

{

if (inputBox.Text == String.Empty)

{

MessageBox.Show("Plaese fill in all the text boxes.", "Error",

MessageBoxButtons.OK, MessageBoxIcon.Error);

return;

}

else

{

sum += Int32.Parse(inputBox.Text);

}

}

MessageBox.Show("The Sum is " + sum);

}

}

}