DropdownList绑定的两种方法

动态绑定方法一：动态绑定数据库中的字段。

sqlconnection conn = utilitysqlclass.operatedatabase.returnconn();

string strsql = "select * from companytype";

sqldataadapter ada = new sqldataadapter(strsql, conn);

dataset ds = new dataset();

ada.fill(ds, "companytype");

dropdownlist1.datasource = ds.tables["companytype"].defaultview;

dropdownlist1.datavaluefield = ds.tables["companytype"].columns[1].columnname;

dropdownlist1.datatextfield = ds.tables["companytype"].columns[1].columnname;

dropdownlist1.databind();

ds.dispose();

动态绑定方法二：利用dropdownlist.items.add方法。

protected void page_load(object sender, eventargs e)

{

if (!ispostback)

try

conn.open();

this.dropdownlist1.items.add("");

string strsql = "select companytype from companytype";

sqlcommand com = new sqlcommand(strsql, conn);

sqldatareader dr = com.executereader();

while (dr.read())

this.dropdownlist1.items.add(dr["companytype"].tostring());

}

catch (exception ex)

response.write("<scirpt>alert('" + ex.message.tostring() + "')</script>");

finally

conn.close();

第一种方法：

        string connstring = configurationsettings.appsettings["connectionstring"];

         //创建一个sqlconnection

         sqlconnection conn = new sqlconnection( connstring );        

         string sql_select = "select id, itemname from ddlitem order by id desc";

         //构造一个sqldataadapter

         sqldataadapter myadapter = new sqldataadapter( sql_select, conn);

         //開始读取数据

         conn.open();

         dataset dataset = new dataset();

         myadapter.fill( dataset,"table1" );

         conn.close();

         //開始绑定dropdownlist

         //指定dropdownlist使用的数据源

         dropdownlist1.datasource = dataset.tables["table1"].defaultview;

         //指定dropdownlist使用的表里的那些字段

         dropdownlist1.datatextfield = "itemname"; //dropdownlist的text的字段

         dropdownlist1.datavaluefield = "id";//dropdownlist的value的字段

         dropdownlist1.databind();

另外一种方法：

        con.open();

        sqlcommand cmd = new sqlcommand(strsql,con);

        sqldatareader dr = cmd.executereader();

        while (dr.read())

        {     

            dropdownlist1.items.add(new listitem(dr["status"].tostring(), dr["status_id"].tostring()));

        }