A與B都是3*3 的矩陣,求相乘結果 (10/8)

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 WindowsFormsApplication2
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            int[,] a = new int[4, 4];
            int[,] b = new int[4, 4];
            int[,] c = new int[4, 4];
            String output;
            a[1,1] = int.Parse(textBox1.Text);
            a[1, 2] = int.Parse(textBox2.Text);
            a[1, 3] = int.Parse(textBox3.Text);
            a[2, 1] = int.Parse(textBox4.Text);
            a[2, 2] = int.Parse(textBox5.Text);
            a[2, 3] = int.Parse(textBox6.Text);
            a[3, 1] = int.Parse(textBox7.Text);
            a[3, 2] = int.Parse(textBox8.Text);
            a[3, 3] = int.Parse(textBox9.Text);
            b[1, 1] = int.Parse(textBox10.Text);
            b[1, 2] = int.Parse(textBox11.Text);
            b[1, 3] = int.Parse(textBox12.Text);
            b[2, 1] = int.Parse(textBox13.Text);
            b[2, 2] = int.Parse(textBox14.Text);
            b[2, 3] = int.Parse(textBox15.Text);
            b[3, 1] = int.Parse(textBox16.Text);
            b[3, 2] = int.Parse(textBox17.Text);
            b[3, 3] = int.Parse(textBox18.Text);
           
            c[1, 1] = a[1, 1] * b[1, 1] + a[1, 2] * b[2, 1] + a[1, 3] * b[3, 1];
            c[1, 2] =a[1, 1] * b[1, 2] + a[1, 2] * b[2, 2] + a[1, 3] * b[3, 2];
            c[1, 3] =a[1, 1] * b[1, 3] + a[1, 2] * b[2, 3] + a[1, 3] * b[3, 3];
            c[2, 1] =a[2, 1] * b[1, 1] + a[2,2] * b[2, 1] + a[2 ,3]* b[3, 1];
            c[2, 2] =a[2, 1] * b[1, 2] + a[2,2] * b[2, 2] + a[2 ,3]* b[3, 2];
            c[2, 3] =a[2, 1] * b[1, 3] + a[2,2] * b[2, 3] + a[2 ,3]* b[3, 3];
            c[3, 1] =a[3, 1] * b[1, 1] + a[3, 2] * b[2, 1] + a[3, 3] * b[3, 1];
            c[3, 2] =a[3, 1] * b[1, 2] + a[3, 2] * b[2, 2] + a[3, 3] * b[3, 2];
            c[3, 3] = a[3, 1] * b[1, 3] + a[3, 2] * b[2, 3] + a[3, 3] * b[3, 3];
            output = Convert.ToString(c[1,1]);
            textBox19.Text = output;
            output = Convert.ToString(c[1, 2]);
            textBox20.Text = output;
            output = Convert.ToString(c[1, 3]);
            textBox21.Text = output;
            output = Convert.ToString(c[2, 1]);
            textBox22.Text = output;
            output = Convert.ToString(c[2, 2]);
            textBox23.Text = output;
            output = Convert.ToString(c[2, 3]);
            textBox24.Text = output;
            output = Convert.ToString(c[3, 1]);
            textBox25.Text = output;
            output = Convert.ToString(c[3, 2]);
            textBox26.Text = output;
            output = Convert.ToString(c[3, 3]);
            textBox27.Text = output;
        }
    }
}