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PODefault radio button not triggering an UpdateControl postback
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  1. PODefault radio button not triggering an UpdateControl postback
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    copied!<p>I have three radio buttons on a form - A, B, C. Each of these selections populates a dropdown list with data specific to the option. When the form loads, I set option A to be checked (as the default). </p> <p>When I select buttons B or C, the AsyncPostBack triggers fine and the dropdown is populated. BUT, subsequently selecting A from either B or C does not trigger the event.</p> <p>I suspect that because A was checked when the form loaded, the browser is not seeing any "change" to raise the event. </p> <p>So what can be done to enable the default A button recognise it is being changed from B or C in order to raise the postback?</p> <p>I have tried both setting the checked state of button A in code on inital loading of the page only (ie IsPostBack is False) and alternatively setting the checked attribute of the radiobutton in the html, with the same results. If I don't default the radio button the functionality works as expected, except I don't have the radio button and dropdown list defaulted when the page first loads.</p> <hr> <p>The html...</p> <pre><code>&lt;asp:RadioButton ID="radBook" runat="server" AutoPostBack="true" GroupName="grpArticleType" Text="Book" /&gt; &lt;asp:RadioButton ID="radCD" runat="server" AutoPostBack="true" GroupName="grpArticleType" Text="CD" /&gt; &lt;asp:RadioButton ID="radDVD" runat="server" AutoPostBack="true" GroupName="grpArticleType" Text="DVD" /&gt; &lt;asp:UpdatePanel ID="pnlTasks" runat="server" UpdateMode="Conditional" RenderMode="Inline"&gt; &lt;ContentTemplate&gt; &lt;asp:DropDownList ID="dropShippingSize" runat="server" CssClass="dropdownMandatory"&gt;&lt;/asp:DropDownList&gt; &lt;/ContentTemplate&gt; &lt;Triggers&gt; &lt;asp:AsyncPostBackTrigger ControlID="radBook" /&gt; &lt;asp:AsyncPostBackTrigger ControlID="radCD" /&gt; &lt;asp:AsyncPostBackTrigger ControlID="radDVD" /&gt; &lt;/Triggers&gt; &lt;/asp:UpdatePanel&gt; </code></pre> <hr> <p>The code behind...</p> <pre><code>Sub Page_Load If Not Me.IsPostBack Then radBook.Checked = True End If End Sub Private Sub rad_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs) _ Handles radBook.CheckedChanged, radCD.CheckedChanged, radDVD.CheckedChanged zLoadShippingSizeDropdown() End Sub </code></pre>
 

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