TextBox.DataBindings.Add(new Binding("Text", ListBox, "SelectedValue.name"));

TextBox.DataBindings.Add(new Binding("Text", ListBox.SelectedValue, "name"));

textBox1.DataBindings.Add(new Binding("Text", listBox1, "selectedvalue"));

if (textBox1.DataBindings.Count == 0) {
    // OK to data bind textBox1.
}