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POWhy do unrelated (autopostback) methods get called when an Asp.Net ListBox autopostback method is invoked?
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copied!<p>I'm sure this is simple but it's driving me nuts.</p> <p>I have a ListBox on my page to show artists, which calls a method when the index is changed, and a button which loads an artist from that list in another page when clicked:</p> <pre><code><asp:ListBox ID="lbArtists" runat="server" Rows="1" AutoPostBack="true" OnSelectedIndexChanged="ShowArtistsWorks" /> <asp:Button ID="btnEditArtist" runat="server" Text="Edit the artist" OnClick="LoadArtist" /> </code></pre> <p>Further on, I have a similar list of links, which also has an autopostback method:</p> <pre><code><asp:ListBox ID="lbLinks" runat="server" Rows="1" AutoPostBack="true" OnSelectedIndexChanged="LoadLink" /> </code></pre> <p>The problem is, when I invoke <code>ShowArtistsWorks()</code> by clicking <code>btnEditArtist</code>, the <code>LoadLink()</code> method also gets called. Why is that happening? Why would that get called when I haven't changed the index on the <code>lbLinks</code> ListBox? It shouldn't be going near that method.</p> <p><strong>EDIT:</strong> (relevant) Code-behind methods (</p> <pre><code>protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack){ GetArtists(); // populates artists listbox GetLinks(); // populates links listbox } } protected void LoadArtist(object sender, EventArgs e){ if (lbArtists.SelectedValue != "") Response.Redirect("Artist.aspx?id=" + lbArtists.SelectedValue); } protected void LoadLink(object sender, EventArgs e) { if (lbLinks.SelectedValue != "") Response.Redirect("Link.aspx?id=" + lbLinks.SelectedValue); } </code></pre> <p><strong>EDIT #2:</strong> I could easily kludge a fix for this in the individual methods to stop them happening when they shouldn't, but I want to understand why methods that I don't call, and that only get called from one place, get invoked inadvertently.</p> <p><strong>ACCEPTED ANSWER:</strong> Even though Boon (now CRice) got in first with an explanation and a solution, I decided to accept Jeff's more thorough explanation because that was what I wanted, a more in-depth analysis. Thanks to everyone who answered.</p>

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