下拉框数据绑定两种方式

1、利用cs包，DataAccess.cs

#region
string m_str = @"select sname from service group by sname";
DataTable m_dt = DataAccess.DBHelper.GetList(m_str);
DropDownList2.DataValueField = "sname";
DropDownList2.DataTextField = "sname";
绑定数据源
this.DropDownList2.DataSource = m_dt;
DropDownList2.DataBind();

DropDownList2.Items.Insert(0, new ListItem("请选择", ""));
#endregion

而在web.config中

<appSettings>
    
    <add key="DBConnString" value="Data Source=localhost;database=manager;uid=sa;pwd=sa;" />
  appSettings>

2、

SqlConnection conn = new SqlConnection("Data Source = localhost; database = manager; uid=sa; pwd=sa;");
        conn.Open();

        //任务类型绑定
        #region
        SqlDataAdapter sdt = new SqlDataAdapter("select sname from service group by sname", conn);

        DataSet dt = new DataSet();
        sdt.Fill(dt);
        DropDownList2.DataValueField = "sname";
        DropDownList2.DataTextField = "sname";
        this.DropDownList2.DataSource = dt;
        DropDownList2.DataBind();

        DropDownList2.Items.Insert(0, new ListItem("请选择", ""));
        #endregion
        conn.Close();