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PODynamically created sub-classed dropdownlist not firing event
 

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  1. PODynamically created sub-classed dropdownlist not firing event
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    <p>There's loads of posts on this subject on the net, but I cant find one that fits my situation;</p> <p>I've have a BasePage class, which my .aspx inherit from; I also have BaseLabel &amp; BaseDDL classes, which extend Label &amp; Dropdownlist respectively. On top of this I have a ReadyDDL class, which combines BaseLabel &amp; BaseDDL into a single control (but this is a class, not a user control) and renders them with their own Div, Table, TableRow, TableCells, &amp; another Label. The ReadyDDL class enables me to define label &amp; dropdownlist &amp; layout in a single html statement as per:</p> <pre><code>&lt;moc:ReadyDDL ID="Person" runat="server" Member="@UserID" Caption="Create strike for" DataSourceSQL="SELECT ID, UserName FROM [User] WHERE isDeleted = 0 AND ClientID = 3" TextField="UserName" ValueField="ID" OnSelectedIndexChanged="ddl_SelectedIndexChanged" /&gt; </code></pre> <p>However I have a problem or two:</p> <p>a) The event doesnt fire. The posts I have read on this subject say that the dropdown must be recreated OnInit &amp; all will be fine. BUT -</p> <p>I'm not dynamically creating a dropdownlist, but a custom extension of one - thus the code which creates the dropdownlist isnt in my aspx, where the event handler is defined, but is in a separate .cs file and accordingly, I cannot write</p> <p>ddl.SelectedIndexChanged += new EventHandler(X);</p> <p>because X doesnt exist in the class, only the page. </p> <p>The only way I've found to get around this is to expose a string property (OnSelectedIndexChanged) which sets another property in BaseDDL, and when BaseDDL is rendered, to add the OnSelectedIndexChanged property to the markup produced. </p> <p>The html produced looks ok, and on screen it looks ok, and it does postback when I change the selection in the control, but the eventhandler doesnt fire: it currently just contains a couple of assignment statements, which I have a breakpoint on, and which isnt reached. </p> <p>On reflection, I suppose, rendering the handler only adds the event to the control in so far as the client is concerned, and the server doesnt know about it - but how can I overcome this, and define the handler at control initialisation, when the handler isnt in the same source code file as the initialisation code?</p> <p>Does anyone have any ideas on either (1) getting the event to fire, or (2) how I can define the event in code, rather than via rendering?</p> <p>Any questions please ask. Any help or suggestions will be appreciated, and I will mark Q as answered if suitable information comes.</p> <p>b) the selected value is lost on postback. I know I have to do something with Viewstate, but I havent figured out just what, yet. If you know how I can implement a solution to this, a short example would be much appreciated.</p>
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    1. USJohn Bingham
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    1. COwhere did you set `AutoPostBack=true` on the dropdown?
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      1. USWaqas Raja
    2. COin ReadyDDL when an event is being recorded.
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      1. USJohn Bingham
 

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