Question

我在更新面板中放了2个Dropdownlist。每当第一个下拉列表选择索引更改第二个下拉列表的项目更改。（如国家/地区..在我的情况下，这是其城市区域）。

每当我更改第一个下拉列表（DDLCity1）selectedindex没问题，它工作正常。但仅两次。假设，在页面加载后我选择“LA”没问题，LA的区域将加载到另一个下拉列表DDLArea1中。然后我做了更改，选择“纽约”城市，再次下拉列表将正常工作。

但是现在他们试图我的第二个下降列表显示没有变化!!!!!它仍然显示最后的结果。

IN SORT，回发只能工作2次。

进行测试我在下拉列表的indexchange上放了一个警告消息，它只弹出2次。好像回发只有2次:(（plzz帮帮我;

<pre>

 <asp:UpdatePanel ID="UpdatePanel1" runat="server" ViewStateMode="Enabled" UpdateMode="Always">
                                <ContentTemplate>
                                    <asp:DropDownList ID="DDLCity1" runat="server" AutoPostBack="false" OnSelectedIndexChanged="DDLCity_SelectedIndexChanged"
                                        ViewStateMode="Enabled">
                                        <asp:ListItem Text="- All City -" />
                                    </asp:DropDownList>
                                    <asp:DropDownList ID="DDLArea1" runat="server" Style="margin-bottom: 0px" OnSelectedIndexChanged="DDLArea_SelectedIndexChanged"
                                        AutoPostBack="false" ViewStateMode="Enabled">
                                        <asp:ListItem Text="- Anywhere -" />
                                    </asp:DropDownList>
                                    <span style="position: absolute;">
                                        <asp:UpdateProgress ID="UpdateProgress1" runat="server">
                                            <ProgressTemplate>
                                                <img src="img/loading.gif" alt="Alternate Text" />
                                            </ProgressTemplate>
                                        </asp:UpdateProgress>
                                    </span>


                                </ContentTemplate>
                                <Triggers>
                                    <asp:AsyncPostBackTrigger ControlID="DDLCity1" EventName="SelectedIndexChanged" />
                                </Triggers>
                                <Triggers>
                                    <asp:AsyncPostBackTrigger ControlID="DDLArea1" EventName="SelectedIndexChanged" />
                                </Triggers>
                            </asp:UpdatePanel>

<code>
 protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
        DDLCity1.DataSource = objsql.GetTable("select distinct city from tblCity where status=1 order by city");
        DDLCity1.DataTextField = "city";
        DDLCity1.DataValueField = "city";
        DDLCity1.DataBind();
        DDLCity1.Items.Insert(0, new ListItem("- All India -", "- All India -"));
        if (Request.Cookies["ddCityCookie"] != null)
        {
            ddlCity.SelectedIndex = int.Parse(Request.Cookies["ddCityCookie"].Value);

            if (Request.Cookies["ddAreaCookie"] != null)
            {
                ddlArea.SelectedIndex = int.Parse(Request.Cookies["ddAreaCookie"].Value);
            }
        }
}
protected void DDLCity_SelectedIndexChanged(object sender, EventArgs e)
{


    DropDownCityIndexChange();

    DDLArea1.SelectedIndex = 0;

}
protected void DDLArea_SelectedIndexChanged(object sender, EventArgs e)
{
    HttpCookie ddAreaCookie = new HttpCookie("ddAreaCookie");
    ddAreaCookie.Value = DDLArea1.SelectedIndex.ToString();
    ddAreaCookie.Expires = DateTime.Now.AddYears(1);
    Response.Cookies.Add(ddAreaCookie);
}
public void DropDownCityIndexChange()
{
    DDLArea1.Items.Clear();

    DDLArea1.DataSource = null;

    HttpCookie ddCityCookie = new HttpCookie("ddCityCookie");
    ddCityCookie.Value = DDLCity1.SelectedIndex.ToString();
    ddCityCookie.Expires = DateTime.Now.AddYears(1);
    Response.Cookies.Add(ddCityCookie);


    DataSet ds = new DataSet();

    if (DDLCity1.SelectedItem.Text != "- All India -")
    {
        DataTable dt = new DataTable();
        dt = objsql.GetTable("select area from tblCity where city='" + DDLCity1.SelectedItem.Text + "' and status=1 order by area");
        if (dt.Rows[0]["area"].ToString() != null && dt.Rows[0]["area"].ToString() != "")
        {
            DDLArea1.DataSource = dt;
            DDLArea1.DataTextField = "area";
            DDLArea1.DataValueField = "area";
            DDLArea1.DataBind();
        }


    }

    DDLArea1.Items.Insert(0, new ListItem("- Anywhere -", "- Anywhere -"));

}
</code>

Answer 1

删除ClientIDMode =＆＃34;静态＆＃34;属性格式

Updatepanel内的下拉列表无法正常工作

1 个答案: