private void Button5_Click(object sender, EventArgs e)
{
SelectBox box = new SelectBox();
box.AllowMultiSelection = false;
box.Items = new string[] { "选项1", "选项2", "选项3", "选项4", "选项5", "选项6" };
box.CheckFormat = (list) =>
{
if (list.Count > 0)
{
return(true);
}
return(false);
};
box.ShowDialog();
}