Filling dynamic textboxes from .dat file

Question

I made a n-variable linear equation solver for a semester homework. It works fine (I already took some help from the site) only one feature is left which is loading the variables from the '.dat' file and copying them in the dynamic textboxes in the right order.

The jagged array is holding the variables for example, if the I have '2x+y=5', '3x-y=4' in my array, it should be changed to {2,1,5} and {3,-1,4}, the "ismeretlenek" represents the number of the variables.

How can I fill these textboxes from the '.dat' file?

ismeretlen = (int)numericUpDown1.Value;

TB = new TextBox[ismeretlen][];

for(int i = 0; i < ismeretlen; i++)
    TB[i] = new TextBox[ismeretlen + 1];


int height = 20;
int width = 40;
int curX = 10;
int curY = 10;

for(int i = 0; i < ismeretlen; i++)
{
    for(int j = 0; j < ismeretlen + 1; j++)
    {
        TextBox txtbox = new TextBox();
        txtbox = new TextBox();
        txtbox.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
        txtbox.Left = curX;
        txtbox.Top = curY;
        txtbox.Width = width;
        txtbox.Height = height;
        txtbox.Font = new Font(txtbox.Font.FontFamily, 14);
        txtbox.BackColor = Color.Azure;
        txtbox.TextAlign = HorizontalAlignment.Center;
        txtbox.Text = "0";

        TB[i][j] = txtbox;
        this.panel1.Controls.Add(TB[i][j]);

        curX += width + 15;
    }

    curX = 10;
    curY = curY + height + 20;
    }

}

private void Save_Click(object sender, EventArgs e)
{
    for (int a = 0; a < ismeretlen; a++)
        segéd[a] = new double[ismeretlen + 1];

    for (int a = 0; a < ismeretlen; a++)
    {
        for (int b = 0; b < ismeretlen + 1; b++)
        {
            segéd[a][b] = double.Parse(TB[a][b].Text);

        }
    }

    string file = ismeretlen+"ismeretlen.dat";
    FileStream fs = new FileStream(file, FileMode.Create);
    BinaryWriter bw = new BinaryWriter(fs);
    for (int r = 0; r < ismeretlen; r++)
        for (int t = 0; t < ismeretlen + 1; t++)
           bw.Write(segéd[r][t]);

    bw.Close();
    fs.Close();

}

private void Load_Click(object sender, EventArgs e)
{

}

}

Answer 1

        /* example:
         * 2x+y=5
         * 3x-y=4
         */

        var outofFile = new List<string> { "2x+y=5", "3x-y=4" };

        var terms = outofFile.Select(x => x.Split(new[] { '+', '-', '=' }));

        // gets all the numbers to a List<List<double>
        var numbers = terms.Select(equalation => equalation.Aggregate(new List<double>(), (List<double> listPerLine, string term) => // term is something like '2x' or '4'
        {
            double number;
            if (!double.TryParse(term, out number)) // if no variable inside just a number you can convert it and return it
            {
                // cut the variable away eg. 2x -> 2
                var numberstring = term.Substring(0, term.Length - 1);
                if (numberstring.Length == 0)
                    number = 1; // eg. if there is only y -> '' -> 1
                else
                    number = double.Parse(numberstring); // eg 2x -> 2 
            }
            listPerLine.Add(number);
            return listPerLine;
        })).ToList();

        /* now you can access the values like this
         *  (indizes zero based)
         * numbers[equalation indizes][inner coeffizient indizes]
         * 
         * check out the values
         * 
         * that way you can assign them to the textboxes.
         */

        var _0_0 = numbers[0][0];
        var _0_1 = numbers[0][1];
        var _0_2 = numbers[0][2];
        var _1_0 = numbers[1][0];
        var _1_1 = numbers[1][1];
        var _1_2 = numbers[1][2];

This shall give you an idea of how to do this. Simply debug it and understand it :) then you can continue assigning it to the textboxes..

Sure this may be improved, but anyway im going to sleep now