ASP.NET页面事件调用两次

Question

I have code in one of my pages which is as given below:

<asp:button id="btnTest" runat="server" onclick="btnTest_click" />
<div class="TomasForm">
        <ul>
            <li>
                <asp:Label ID="LineL" runat="server" AssociatedControlID="Lines" Text="<%$ FieldLabelResources:Units, Line, false %>" />
                <asp:DropDownList ID="Lines" runat="server" AutoPostBack="true" AppendDataBoundItems="true"
                    DataTextField="Name" DataValueField="Id" OnSelectedIndexChanged="Lines_SelectedIndexChanged">
                    <asp:ListItem Text="<%$ Resources:Common, SelectOne %>" Value="-1" />
                </asp:DropDownList >
            </li>
        </ul>
    </div>

My issue is when I change the Lines dropdownlist value, the page(page_load and Lines_SelectedIndexChanged events) is getting called twice. The page is behaving normal when I click btnTest button.

Could anyone let me know why this is happening??

Thanks, Mahesh

Answer 1

您需要在DropDownList中将AutoPostBack更改为False。

Answer 2

你应该为下拉列表和代码中的AutoPostback设置为false，确保你在Page_Load中编写这样的条件if（！isPostBack（））{//编写代码，它只能工作一次}