DropDownList数据绑定

绑定DataTable

   
     //创建一个SqlConnection
 SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=pubs;Integrated Security=True");
 
 string SQL_Select = "select job_id,job_desc from dbo.jobs order by job_id desc";

 //构造一个SqlDataAdapter
 SqlDataAdapter myAdapter = new SqlDataAdapter(SQL_Select, conn);

 try
 {
 //开始读取数据
 conn.Open();
 try
 {
 DataSet dataSet = new DataSet();
 myAdapter.Fill(dataSet, "jobs");

 //指定DropDownList使用的数据源
 DropDownList1.DataSource = dataSet.Tables["jobs"].DefaultView;

 //指定DropDownList使用的表里的那些字段
 DropDownList1.DataTextField = "job_desc"; //dropdownlist的Text的字段
 DropDownList1.DataValueField = "job_id";//dropdownlist的Value的字段

 DropDownList1.DataBind();
 }
 catch (Exception ex)
 {
 throw ex;
 }
 finally
 {
 conn.Close();
 conn.Dispose();
 }
 }
 catch (Exception ex)
 {
 throw ex;
 }

绑定枚举
方法一:可绑定Text和Value.

 

   
     foreach (int i in Enum.GetValues(typeof(EnumArea)))
 {
 ListItem item = new ListItem(Enum.GetName(typeof(EnumArea), i), i.ToString());
 DropDownList1.Items.Add(item);
 }

方法二:只绑定Text.

 

   
     DropDownList1.DataSource = Enum.GetValues(typeof(EnumArea));
DropDownList1.DataBind();

 

 

dropdownlist动态绑定

...
DataSet ds=new DataSet();
SqlDataAdapter command=new SqlDataAdapter("",conn);
...
conn.Open();    //打开数据库连接
command.SelectCommand.CommandText="Select a,b FROM tb1";
command.Fill(ds,"table1");
conn.Close();

方法一:
不设定dropdownlist的datatextfield,datavaluefield

for(int i=0;i<ds.Tables["table1"].Rows.Count;i++)
{
   dropdownlist.Items.Add(new ListItem(ds.Tables["table1"].Rows[i][1].ToString(),ds.Tables["table1"].Rows[i][0].ToString()));
}

方法二:
设定dropdownlist的datatextfield="b",datavaluefield="a"
 DataSet  ds = m.ManagerRead();
        b_operator.DataSource = ds.Tables[0];
        b_operator.DataTextField = "a_name";
        b_operator.DataValueField = "id";
        b_operator.DataBind();
        ds.Clear();
        ds.Dispose();

从数据库中读出DropDownList的选中值

从数据库中读出DropDownList的选中值
dropdownlist.aspx
<asp:DropDownList ID="DropDownList1" runat="server">
 <asp:ListItem>语文</asp:ListItem>
 <asp:ListItem>体育</asp:ListItem>
 <asp:ListItem>数学</asp:ListItem>
</asp:DropDownList>

dropdownlist.cs
string str = "体育";//这一项可以从数据库中读出
for (int j = 0; j < this.DropDownList1.Items.Count; j++)
{
 if (str == this.DropDownList1.Items[j].Text.ToString())
 {
  this.DropDownList1.Items[j].Selected = true;
 }
}