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上一例中静态填充选择框的值，但这不太适合那些值在数据库中会更改的情况。因为 select htmlcontrol 也支持 ienumerable
datasource 属性，可以转而使用选择查询动态填充选择框，这将保证数据库和用户界面始终同步。下面的示例说明此过程。
<%@ import namespace=”system.data” %>
<%@ import namespace=”system.data.sqlclient” %>
<html>
<script language=”c#” runat=”server”>
sqlconnection myconnection;
protected void page_load(object src, eventargs e)
{
myconnection = new sqlconnection(“user id=sa;password=;initial catalog=pubs;data source=jeff”);
if (!ispostback)
{
sqldataadapter mycommand = new sqldataadapter(“select distinct state from authors”, myconnection);
dataset ds = new dataset();
mycommand.fill(ds, “states”);
myselect.datasource= ds.tables[“states”].defaultview;
myselect.databind();
}
}
public void getauthors_click(object sender, eventargs e)
{
string selectcmd = “select * from authors where state = @state”;
sqldataadapter mycommand = new sqldataadapter(selectcmd, myconnection);
mycommand.selectcommand.parameters.add(new sqlparameter(“@state”, sqldbtype.nvarchar, 2));
mycommand.selectcommand.parameters[“@state”].value = myselect.value;
dataset ds = new dataset();
mycommand.fill(ds, “authors”);
mydatagrid.datasource= ds.tables[“authors”].defaultview;
mydatagrid.databind();
}
</script>
<body style=”font: 10.5pt 宋体”>
<form runat=”server”>
<h3><font face=”宋体”>对 datagrid 控件的动态参数化选择</font></h3>
选择州:
<select id=”myselect” datatextfield=”state” runat=”server”/>
<input type=”submit” onserverclick=”getauthors_click” value=”获取作者” runat=”server”/><p>
<asp:datagrid id=”mydatagrid” runat=”server”
width=”700″
backcolor=”#ccccff”
bordercolor=”black”
showfooter=”false”
cellpadding=3
cellspacing=”0″
font-name=”宋体”
font-size=”8pt”
headerstyle-backcolor=”#aaaadd”
enableviewstate=”false”
/>
</form>
</body>
</html>
