Practica 6 visual

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

namespace Ejercicio_47
{
public partial class frmEjercicio47 : Form
{
public frmEjercicio47()
{
InitializeComponent();
}
//Declaracion de variables globales y arreglo
int[,] num = new int[4, 5];
int[] ordenar = new int[20];
int ren = 0;
int col = 0;
int p, i, m, r, c, j, k,me;
private void cmdtabla_Click(object sender, EventArgs e)
{

cmdnum.Enabled = true;
cmdtabla.Enabled = false;

//creacion de tabla aleatoria
Random aleatorio = new Random();

for (ren = 0; ren < 4; ren++)
{
for (col = 0; col < 5; col++)
{
num[ren, col] = aleatorio.Next(50);

txttabla.Text = txttabla.Text + num[ren, col] + "\t";
}
txttabla.Text = txttabla.Text + "\r\n";
}

}

private void cmdnum_Click(object sender, EventArgs e)
{
txttabla.Clear();
lblDespliegue.Visible = true;

for (p = 1; p <= 20; p++)
{
me = num[0, 0];
r = 0;
c = 0;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 5; j++)
{
if (num[i, j] < me)
{
me = num[i, j];
r = i;
c = j;
}
}
}
ordenar[k] = me;
num[r, c] = 9999;
k++;

}

for (k = 0; k < 20; k++)
{
txttabla.Text = txttabla.Text + ordenar[k].ToString() + ", ";
}

}

private void cmdLimpiar_Click(object sender, EventArgs e)
{
cmdtabla.Enabled = true;
cmdnum.Enabled = false;
lbltabla.Visible = true;
lblDespliegue.Visible = false;
txttabla.Text = "";
txttabla.Clear();

}

private void cmdSalir_Click(object sender, EventArgs e)
{
Close();
}

private void lblDespliegue_Click(object sender, EventArgs e)
{

}

private void txttabla_TextChanged(object sender, EventArgs e)
{

}
}
}