两种添加数据到DropDownList 控件的方法

方法一：

 1     string  sql = " SELECT * FROM NewsClass ORDER BY ORDERID DESC " ; 
 2
 3    OleDbConnection conn = new  OleDbConnection();
 4
 5    conn.ConnectionString = ConnectionString;
 6    conn.Open();
 7
 8    OleDbCommand cmd  =   new  OleDbCommand(Sql,Conn);
 9    OleDbDataReader dr =  cmd.ExecuteReader();
10
11       // 将数据添加到 DropDownList
12     while (dr.Read())
13     {
14        ddl.Items.Add(new ListItem(dr["ClassName"].ToString(),dr["ClassId"].ToString()));
15   }
16    dr.Close();
17
18    cmd.Dispose();
19    conn.Close;
20    conn.Dispose();
21

方法二：

 1    string  sql = " SELECT * FROM NewsClass ORDER BY ORDERID DESC " ;
 2
 3    OleDbConnection conn = new  OleDbConnection();
 4    conn.ConnectionString = ConnectionString;
 5    conn.Open();
 6
 7    DataSet ds = new  DataSet();
 8    OleDbDataAdapter da = new  OleDbDataAdapter(sql,conn);  
 9    da.Fill(ds, " ClassTable " );
10
11     // 将数据添加到 DropDownList
12    ddl.DataSource = ds;
13    ddl.DataTextField  =   " ClassName " ;
14    ddl.DataValueField  =   " ClassID " ;
15    ddl.DataBind();
16
17    ds.Dispose();
18    conn.Close;
19    conn.Dispose();
20
21