Windows forms calculator algorithms. Sorting and highest/lowest numbers

Question

I'm currently working on a calculator but 2 of my algorithms are not working correctly.

1. In my history (listbox) I get the numbers from the calculator and I have a bottom that finds the smallest number. I get an error with my code.

2. I want to have a [sorting] bottom that sorts the numbers ascending or descending. I've tried things as listbox1.sorted but I only get it to work as alphabetic.

If you know what I'm doing wrong with nr.1 or know how to fix a sorting algorithm please let me know.

 int count = 0;
 int tal = 0;
 double Mtal = 999999999999999999;
 bool hit;
 int count1 = 0;
 private void button26_Click(object sender, EventArgs e)
    {
        while (count < 100)
        {
            foreach (var Listboxitem in listBox1.Items)
            {
                hit = false;
                if (Convert.ToDouble(Listboxitem) < Mtal)
                {

                    Mtal = Convert.ToDouble(Listboxitem);
                    hit = true;
                }
                count = count + 1;
                if (hit)
                {
                    count1 = count;
                }
            }
        }
        this.listBox1.SelectedIndex = count1 - 1;

    }

Answer 1

Your values in ListBox are Integers. So change the declaration of your variable Mtal from double to int. And then, instead of Convert.ToDouble() use int.Parse(), because you need integers for comparing to existing min value. Something like this should work for you:

 int count = 0;
 int tal = 0;
 int Mtal = int.MaxValue;
 bool hit;
 int count1 = 0;
 private void button26_Click(object sender, EventArgs e)
 {
     while (count < 100)
     {
          foreach (var Listboxitem in listBox1.Items)
          {
             hit = false;
             if (int.Parse(Listboxitem.ToString()) < Mtal)
             {

                 Mtal = int.Parse(Listboxitem.ToString());
                 hit = true;
             }
             count = count + 1;
             if (hit)
             {
                count1 = count;
             }
        }
    }
    this.listBox1.SelectedIndex = count1 - 1;

 }

And then for Ordering I would suggest you to use LINQ on List<ListItem>. For your example:

private void button_OrderByDescencing_Click(object sender, EventArgs e)
 {
        List<ListItem> items= new List<ListItem>();
        foreach (ListItem a in lb.Items)
        {
            items.Add(a);
        }
        items=items.OrderByDescending(a => int.Parse(a.Value)).ToList();
        foreach (ListItem a in items)
        {
             listBox1.Items.Add(a);
        }

 }

And for ascending:

 private void button_OrderByAscending_Click(object sender, EventArgs e)
 {
        List<ListItem> items= new List<ListItem>();
        foreach (ListItem a in lb.Items)
        {
            items.Add(a);
        }
        items= items.OrderBy(a => int.Parse(a.Value)).ToList();
        foreach (ListItem a in items)
        {
             listBox1.Items.Add(a);
        }

 }