在我调试程序之后，
该页面向我显示以下错误。
我不知道要解决此错误，是缺少程序集吗？

这是他们显示的错误:

编译错误

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS1061: 'ASP.dcbrequestlogcriteria_aspx' does not contain a definition for 'ddlTelco_SelectedIndexChanged' and no extension method 'ddlTelco_SelectedIndexChanged' accepting a first argument of type 'ASP.dcbrequestlogcriteria_aspx' could be found (are you missing a using directive or an assembly reference?)

<span class="fieldlable">Telco:</span>
<span>
<asp:DropDownList ID="ddlTelco" runat="server" DataTextField="Text" DataValueField="Value"  AutoPostBack="true" OnSelectedIndexChanged="ddlTelco_SelectedIndexChanged" SelectMethod="LoadTelco"  Enabled="false"></asp:DropDownList>
</span>
<asp:RequiredFieldValidator ID="RequiredFieldValidatorTelco" runat="server" ErrorMessage="Telco" ControlToValidate="ddlTelco"></asp:RequiredFieldValidator>

最佳答案

这意味着它正在查找您已订阅控件的事件 ddlTelco_SelectedIndexChanged

在标记后面的代码上，为 ddlTelco_SelectedIndexChanged 定义一个事件，或者通过将控件订阅一个事件并生成

ddlTelco.OnSelectedIndexChanged + = ddlTelco_SelectedIndexChanged

    protected void ddlTelco_SelectedIndexChanged(object sender, EventArgs e)
    {
    //Write implementation here
    }

https://stackoverflow.com/questions/41691565/