c#-如何用文本框过滤组合框

我正在做一个程序，但在我的组合框中有很多项，我想用文本框过滤这些项。我希望有人能帮我我试过但没用

public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {   
            BindingSource bs = new BindingSource();
            string column = comboBox1.Text;
            string text = textBox1.Text;enter code here
            string filter = string.Format("{0} like '%{1}%'", column, text);
            bs.Filter = filter;
        }