C# Searching a listBox | 易学教程

问题

I have a large amount of items in a listBox called listBox1. I also have a textBox (textBox1) at the top. I want to be able to type into the textBox and the listBox searches through it's item's and finds ones that contain what I am typing.

For example, say the listBox contains

"Cat"

"Dog"

"Carrot"

and "Brocolli"

If I start typing the letter C, then I want it to show both Cat and Carrot, when I type a it should keep showing them both, but when I add an r it should remove Cat from the list. Is there anyway to do this?

回答1:

Filter the listbox. Try this:

    List<string> items = new List<string>();
    private void Form1_Load(object sender, EventArgs e)
    {
        items.AddRange(new string[] {"Cat", "Dog", "Carrots", "Brocolli"});

        foreach (string str in items) 
        {
            listBox1.Items.Add(str); 
        }
    }

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        listBox1.Items.Clear();

        foreach (string str in items) 
        {
            if (str.StartsWith(textBox1.Text, StringComparison.CurrentCultureIgnoreCase))
            {
                listBox1.Items.Add(str);
            }
        }
    }

回答2:

Here's an pretty good example: http://www.java2s.com/Code/CSharp/Components/UseanAutocompleteComboBox.htm

回答3:

Rudimentary example; however this should get you started...

    public partial class Form1 : Form
    {
        List<String> _animals = new List<String> { "cat", "carrot", "dog", "goat", "pig" };

        public Form1()
        {
            InitializeComponent();

            listBox1.Items.AddRange(_animals.ToArray());
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            String search = textBox1.Text;

            if (String.IsNullOrEmpty(search))
            {
                listBox1.Items.Clear();
                listBox1.Items.AddRange(_animals.ToArray());
            }

            var items = (from a in _animals
                        where a.StartsWith(search)
                        select a).ToArray<String>();

            listBox1.Items.Clear();
            listBox1.Items.AddRange(items);
        } 
    }

回答4:

For getting result which the asked expects, you have to use Contains method instead StartWith method. Like this:-

private void textBox1_TextChanged(object sender, EventArgs e)
    {
        listBox1.Items.Clear();

        foreach (string str in items)
        {
            if (str.ToUpper().Contains(textBox1.Text.ToUpper()))
            {
                listBox1.Items.Add(str);
            }
        }
    }

I was in search for this.

回答5:

I think you need to use a linq query and then databind the result. An example of this in WPF is here, but I believe you can do the same in winforms.

来源：https://stackoverflow.com/questions/4878929/c-sharp-searching-a-listbox

标签

winforms

listbox