3*3矩陣運算

            int[,] a = new int[4,4];
            int[,] b = new int[4,4];
            int[,] c = new int[4,4];
            String c1, c2, c3, c4, c5, c6, c7, c8, c9;
            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];
            c1 = Convert.ToString(c[1, 1]);
            c2 = Convert.ToString(c[1, 2]);
            c3 = Convert.ToString(c[1, 3]);
            c4 = Convert.ToString(c[2, 1]);
            c5 = Convert.ToString(c[2, 2]);
            c6 = Convert.ToString(c[2, 3]);
            c7 = Convert.ToString(c[3, 1]);
            c8 = Convert.ToString(c[3, 2]);
            c9 = Convert.ToString(c[3, 3]);
            textBox19.Text = c1;
            textBox20.Text = c2;
            textBox21.Text = c3;
            textBox22.Text = c4;
            textBox23.Text = c5;
            textBox24.Text = c6;
            textBox25.Text = c7;
            textBox26.Text = c8;
            textBox27.Text = c9;