选择更改后，下拉值将重置 [英] Dropdown Value is getting reset after selectionchanged

问题描述

嗨..



以下是我的代码，即使我使用更新面板下拉列表，我选择不同的值后重置： -

Hi..

Following is my code,even though am using update panel for dropdownlist its getting reset after i select different value:-

<asp:UpdatePanel runat="server" UpdateMode="Always" ChildrenAsTriggers="true">
                   <ContentTemplate>
                       City:
                       <asp:DropDownList ID="ddlCity" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlCity_SelectedIndexChanged">
                       </asp:DropDownList>
                   </ContentTemplate>
                   <Triggers>
                       <asp:AsyncPostBackTrigger ControlID="ddlCity" EventName="selectedindexchanged" />

                   </Triggers>
               </asp:UpdatePanel>

请告诉我，我错过了吗？



谢谢。

Please let me know,wat am i missing?

Thank you.

推荐答案

如果你使用c＃代码动态加载你的下拉列表然后试试这个

if you loading your dropdown dynamically using c# code then try this

protected void Page_Load(object sender, EventArgs e)

{

if (IsPostBack)
    {
//code to load yo dropdown

    }
}

OR

if (!IsPostBack)
    {
//code to load yo dropdown

    }

然后你可以为你的控件设置AutoPostBack =true。



它对我有用。

Then you can set AutoPostBack="true" for yo control.

It worked for me.

Make AutoPostBack = trueas False

Make AutoPostBack="true" as False

In Trigger
<asp:AsyncPostBackTrigger ControlID="ddlCity" EventName="SelectedIndexChanged"/>

in cs you must have
protected void ddlCity_SelectedIndexChanged(object sender, EventArgs e)
{

}

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