我设了  但是没作用啊    一点反应都没有private void checkBoxX5_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBoxX5.Checked)
            {
                comboTree1.Enabled = true;
                CaseType();
                
            }
            else
            {
                
                comboTree1.DataSource = null;
                //comboTree1.DisplayMembers = null;
                //comboTree1.ValueMember = null;
                //comboTree1.GroupingMembers = null;
                //comboTree1.Enabled = false;
            }