当尝试从listBox中删除/删除项目时为什么我得到一个错误：项目集合无法修改？

Question

I have this code where I click the Delete key it should delete an item from the listBox:

private void listBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Delete)
            {
                if (this.listBox1.SelectedIndex >= 0)
                    this.listBox1.Items.RemoveAt(this.listBox1.SelectedIndex);
            }
        }

But as soon as im pressing the delete key im getting an error on the RemoveAt line:

Items collection cannot be modified when the DataSource property is set.

Now I have in other two places in my Form1 where im using the DataSource: First:

private void ListBoxLoadKeys(Dictionary<string, List<string>> dictionary, string FileName)
        {
            using (StreamReader sr = new StreamReader(FileName))
            {
                while ((line = sr.ReadLine()) != null)
                {
                    int i = line.Count();
                    tokens = line.Split(',');
                    dictionary.Add(tokens[0], tokens.Skip(1).ToList());
                    data.Add("Url: " + tokens[0] + " --- " + "Localy KeyWord: " + tokens[1]);
                }
            }
            listBox1.DataSource = data;
        }

Second place:

private void ClearListBox()
        {
            data.Clear();
            listBox1.DataSource = null;
            string sb;
            foreach (KeyValuePair<string, List<string>> kvp in LocalyKeyWords)
            {
                for (int i = 0; i < kvp.Value.Count(); i++)
                {
                    sb = "Url: " + kvp.Key + " --- " + "Local KeyWord: " + kvp.Value[i] + Environment.NewLine;
                    data.Add(sb.ToString());
                }
            }
            listBox1.DataSource = data;
            listBox1.Select();
        }

So what can I use instead the DataSource or to keep it ?

Edited:

Tried this:

private void listBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Delete)
            {
                if (this.listBox1.SelectedIndex >= 0)
                {
                    string obj = this.listBox1.SelectedValue.ToString();
                    data.Remove(obj);
                    listBox1.DataSource = null;
                    listBox1.DataSource = data;
                }
            }

        }

But when clicking the Delete key im getting an error here:

private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            string url = data[e.Index].Substring(0, 5);

            using (Font f = new Font(FontFamily.GenericSansSerif, 8, FontStyle.Regular))
            {
                ColorText.ColorListBox(data, e);
            }

        }

On the string url line: Index was out of range. Must be non-negative and less than the size of the collection

Edited:

I tried to use a flag:

private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            if (deletedKey != true)
            {
                string url = data[e.Index].Substring(0, 5);

                using (Font f = new Font(FontFamily.GenericSansSerif, 8, FontStyle.Regular))
                {
                    ColorText.ColorListBox(data, e);
                }
            }
        }

And:

private void listBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Delete)
            {
                if (this.listBox1.SelectedIndex >= 0)
                {
                    deletedKey = true;
                    string obj = this.listBox1.SelectedValue.ToString();
                    data.Remove(obj);
                    listBox1.DataSource = null;
                    listBox1.DataSource = data;
                }
            }

        }

So now im not getting errors but it's deleting all the items in the listBox I need it to delete only the one im on now/selected.

Answer 1

When using data binding, you remove from the data source and not the ListBox.

private void listBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Delete)
            {
                if (this.listBox1.SelectedIndex >= 0)
                {
                   string obj = this.listBox1.SelectedValue.ToString();
                   data.Remove(obj);
                   listBox1.DataSource = null;
                   listBox1.DataSource = data;
                }
            }
        }

Answer 2

You can add directly to the listbox as follows:

   listbox1.BeginUpdate();
   for (int i = 0; i < kvp.Value.Count(); i++)
                {
                    sb = "Url: " + kvp.Key + " --- " + "Local KeyWord: " + kvp.Value[i] + Environment.NewLine;
                    listbox1.Add(sb.ToString());
                }
   listbox1.EndUpdate();