winform窗体应用程序中combox下拉列表如何获取sql数据库中的值

让下拉列表从sql数据库中获取值

SqlConnection con = new SqlConnection("你的sql连接字符串");
con.Open();
SqlCommand cmd = new SqlCommand("select 部门 from 表", con);
DataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
comboBox1.Items.Add(dr["部门"].ToString());
}

DataTable dt = new DataTable();
            string strcfg = "";
            SqlConnection conn = new SqlConnection(strcfg);//strcfg连接字符串
            string sql = "select * from 部门表";
            SqlCommand comm = new SqlCommand(sql,conn);
            conn.Open();
            SqlDataAdapter sqlData = new SqlDataAdapter(comm);
            sqlData.Fill(dt);
            conn.Close();
            comboBox1.DataSource = dt;
            comboBox1.DisplayMenber = "显示的值";
            comboBox1.ValueMember = "实际的值";