当我在下拉列表中选择一个值时,我会得到一个回传,并且即使在回发之后,我选择的值也会被选中。我如何获得默认值,< - 在回发之后再次选择City - >作为选定值?Dropdownlist回发到默认选定值?
HTML:
<asp:DropDownList ID="ddlCity" Width="200px" runat="server" AutoPostBack="true"
OnSelectedIndexChanged="ddlCity_SelectedIndexChanged"> </asp:DropDownList>
标记:
protected void Page_Load(object sender, EventArgs e)
{
DataTable CityMembersTable = GetCity();
ddlCity.DataSource = CityMembersTable;
ddlCity.DataTextField = "CityName";
ddlCity.DataValueField = "CityID";
ddlCity.DataBind();
ddlCity.Items.Insert(0, new ListItem("<--Choose City-->", ""));
}
protected void ddlCity_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddlCity.SelectedValue == "")
{
return;
}
ddlCity.SelectedValue == "0"; //Dose not work...
}
现在为什么你需要吗?看看代码它似乎不太可能它会被加载绑定,你不会得到您选择的值 – V4Vendetta 2012-01-13 10:03:35
我怀疑'ddlCity_SelectedIndexChanged'永远不会调用,因为您正在page_load中_every_回发中重新绑定DropDownList。把它包装在一个'if(!Page.IsPostBack){...}' – 2012-01-13 10:03:59