文本框更改时如何从列表框中消除项目

Question

I wanna make a small code block about c #.

first think a listbox with elements. then think a blank textbox.

when I write a letter to textbox(dont think just letter, think about a word ,I split it with textbox1_textchanged ),if an element dont have the word it must be deleted from listbox.

example:

here are listbox elements :

abraham
michael
george
anthony

when i type "a",I want michael and george to be deleted,then when I type "n" I want abraham to be deleted(at this point total string is "an")...

Thanks by now (:

Answer 1

private void textBox1_TextChanged(object sender, EventArgs e)
    {
        for (int i = 0; i < listBox1.Items.Count; i++)
        {
            string item = listBox1.Items[i].ToString();
            foreach(char theChar in textBox1.Text)
            {
                if(item.Contains(theChar))
                {
                    //remove the item, consider the next list box item
                    //the new list box item index would still be i
                    listBox1.Items.Remove(item);
                    i--;
                    break;
                }
            }
        }
    }

Answer 2

You could try something like this. It will match what you have in the textbox and remove what doesn't match.

private void textBox1_TextChanged(object sender, EventArgs e)
{
    for (int i = 0; i < listBox1.Items.Count ; i++)
    {
        for (int j = 0; j < textBox1.Text.Length  ; j++)
        {
            if (textBox1.Text[j] != listBox1.Items[i].ToString()[j])
            {
                if (i < 0) break;
                listBox1.Items.RemoveAt(i);
                i = i - 1; // reset index to point to next record otherwise you will skip one
            }

        }

    }
}

Answer 3

You can filter the items that doesn't contain the text and remove them from the listbox:

private void textBox1_TextChanged(object sender, EventArgs e)
{
    var itemsToRemove = listBox1.Items.Cast<object>().Where(x => !x.ToString().Contains(textBox1.Text)).ToList();
    foreach(var item in itemsToRemove)
        listBox1.Items.Remove(item);
}