c# - 2 x 10 随机生成的数字具有相同的总和 c#

Question

我有 2 个列表框，我需要将 10 个随机生成的数字放入其中。然后我需要计算列表框 1 的总和和列表框 2 的总和，并比较它们以查看哪个更大。我确实在每个列表框中得到不同的数字，但出于某种原因，列表框的总和总是相同的。我如何使每个列表框的总和不同。这是我目前的代码。

 private void btnGo_Click(object sender, EventArgs e)
    {

        Random random = new Random();

        listBox1.Items.Clear();
        listBox2.Items.Clear();


        for (int i = 0; i < 10; i++)
        {

            int nummer = random.Next(20);
            int nummer2 = random.Next(20);
            listBox1.Items.Add(nummer);
            listBox2.Items.Add(nummer2);
        }




        if (addListbox1() > addListbox2())
        {
            textBox1.Text = "Listbox1 heeft de hoogste waarde namelijk " + Convert.ToString(addListbox1());
            listBox1.BackColor = Color.Green;
            listBox2.BackColor = Color.Red;


        }

        else
        {

            textBox1.Text = "Listbox2 heeft de hoogste waarde namelijk " + Convert.ToString(addListbox2());
            listBox1.BackColor = Color.Red;
            listBox2.BackColor = Color.Green;


        }



    }
    private int addListbox1()
    {
        int listbox1total = 0;

        for (int k = 0; k < listBox1.Items.Count;)
        {
            listbox1total += Convert.ToInt32(listBox1.Items[k++]);
        }
        return listbox1total;
    }

    private int addListbox2()
    {
        int listbox2total = 0;
        int k = 0;

        while(k < listBox2.Items.Count)
        {
            listbox2total += Convert.ToInt32(listBox1.Items[k++]);

        }
        return listbox2total;
    }

Answer 1

您在代码中有一个错字(复制+粘贴的老故事):

listbox2total += Convert.ToInt32(listBox1.Items[k++]);

应该是

// please, notice "listBox2.Items"
listbox2total += Convert.ToInt32(listBox2.Items[k++]);

即listbox2total 应该是 listBox2.Items 的总和。

为了避免这样的错误，改变设计，不要自己照搬，提取方法:

// Easiest, but not thread safe
private static Random random = new Random();

private static void FillBox(ListBox box, int count = 10) {
  box.Items.Clear();

  box.Items.AddRange(Enumerable
    .Range(0, count)
    .Select(x => (Object) random.Next(20))
    .ToArray());
}

private static int SumBox(ListBox box) {
  return box.Items
    .OfType<Object>()
    .Sum(x => Convert.ToInt32(x));
}

...

FillBox(listBox1);
FillBox(listBox2);

if (SumBox(listBox1) > SumBox(listBox2)) {
  ...
}