“不包含…的定义，也没有扩展方法…接受类型错误的第一个参数

Question

I've got the following error:

'DirectActivity' does not contain a definition for 'ddl_jobcode_Id2' and no extension method 'ddl_jobcode_Id2' accepting a first argument of type 'DirectActivity' could be found (are you missing a using directive or an assembly reference?)

In my aspx, I created a DropDownList like this:

<asp:DropDownList ID="ddl_jobcode_Id2" runat="server" DataSourceID="ddl_ActivityType2"
                            DataTextField="jobCode" DataValueField="ID" SelectedValue='<%# Bind("jobCode_ID2", "{0}") %>'
                            OnDataBound="ddl_jobcode_Id2_DataBound" 
                            onselectedindexchanged="ddl_jobcode_Id2_SelectedIndexChanged1" 
                            AutoPostBack="True">
                        </asp:DropDownList>

I need to add a control so that in the .cs file I worte

protected void ddl_jobcode_Id2_SelectedIndexChanged1(object sender, EventArgs e)
{
    if(this.ddl_jobcode_Id2.SelectedValue == "19" )
     {  ...}}

and it just shows this error on ddl_jobcode_Id2

could anyone help me please? many thanks!!!

Answer 1

I notice you're binding a value to your SelectedValue property. This probably means you have this DropDownList in some Template of a data control. In that case you'll need to set a handler for an event of your data control where your template has been instatiated (I can't tell without knowing the exact control), and FindControl ( "ddl_jobcode_Id2" ) your way to your DropDownList in code-behind.