Extra Unidad 2 _1_consola y windows

PSEUDOCODIGO :
1. INICIO

int valor, sum, prom, n;
n = 0;
sum = 0;
do
{
Imprimir "INTRODUCE VALOR NUMERICO: "
Leer valor
sum=sum+valor;
n=n+1;
}
while (valor!=9999)
sum = sum - 9999;
n = n - 1;
prom = sum / n;
Imprimir "EL PROMEDIO ES: ", prom
FIN


CODIGO EN CONSOLA:

int valor=0,n=0,prom=0,suma=0;

do
{
Console.WriteLine("Introduce valores numericos");

valor = int.Parse(Console.ReadLine());
if (valor != 999)
{

suma = suma + valor;


n = n + 1;
}



} while (valor != 9999);
suma = suma - 9999;
n = n - 1;
prom = suma / n;
Console.WriteLine("el promedio es: {0} ", prom);
Console.ReadKey();




CODIGO EN WINDOWS:
public partial class Form1 : Form
{
int valor, sum, n;
double prom;

public Form1()
{
InitializeComponent();
sum = n = valor = 0;
listBox1.Items.Add("Valores numericos");

}

private void button1_Click(object sender, EventArgs e)
{

valor = int.Parse(textBox1.Text);
if (valor != 9999)
{
listBox1.Items.Add(" " + valor.ToString());
sum = sum + valor;
n = n + 1;
textBox1.Clear();
textBox1.Focus();
}
else
{
n = n - 1;
prom = sum / n;
listBox1.Items.Add("El promedio es: " + prom.ToString());
textBox1.Enabled = false;
button1.Enabled = false;
}

}

private void button2_Click(object sender, EventArgs e)
{
listBox1.Items.Clear();
textBox1.Text = "";
}

private void button3_Click(object sender, EventArgs e)
{
Application.Exit();
}
}