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POAccessing Data Items on Select with ListView
 

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    <p>Writing an asp.net file manager.</p> <p>Essentially, the user clicks on a folder in a TreeView control and the files within that folder are shown in a ListView control.</p> <p><strong>The ListView</strong></p> <pre><code>&lt;asp:listview id="lvFiles" runat="server" onitemdeleting="lvFiles_ItemDeleting" onselectedindexchanging="lvFiles_SelectedIndexChanging"&gt; &lt;layouttemplate&gt; &lt;table cellpadding="2" width="520px" border="1" id="tbl1" runat="server"&gt; &lt;tr id="Tr1" runat="server" style="background-color: #98FB98"&gt; &lt;th id="Th0" runat="server"&gt;&lt;/th&gt; &lt;th id="Th1" runat="server"&gt;Filename&lt;/th&gt; &lt;th id="Th2" runat="server"&gt;Uploaded&lt;/th&gt; &lt;th id="Th3" runat="server"&gt;Last Accessed&lt;/th&gt; &lt;/tr&gt; &lt;tr runat="server" id="itemPlaceholder" /&gt; &lt;/table&gt; &lt;asp:datapager id="DataPager1" runat="server" pagesize="25"&gt; &lt;fields&gt; &lt;asp:nextpreviouspagerfield buttontype="Button" /&gt; &lt;/fields&gt; &lt;/asp:datapager&gt; &lt;/layouttemplate&gt; &lt;emptyitemtemplate&gt; &lt;p&gt;No items&lt;/p&gt; &lt;/emptyitemtemplate&gt; &lt;itemtemplate&gt; &lt;tr runat="server"&gt; &lt;td&gt;&lt;asp:linkbutton id="itemSelected" runat="server" tooltip='&lt;%# Eval("FullName") %&gt;' autopostback="True" commandname="select" text="Select" /&gt; &lt;/td&gt; &lt;td&gt;&lt;asp:label id="fNameLabel" runat="server" text='&lt;%# Eval("Name") %&gt;'&gt;&lt;/asp:label&gt; &lt;/td&gt; &lt;/tr&gt; &lt;/itemtemplate&gt; &lt;selecteditemtemplate&gt; &lt;tr id="Tr2" runat="server"&gt; &lt;td&gt;Selected&lt;/td&gt; &lt;td&gt;&lt;asp:label id="fNameLabel" runat="server" text='&lt;%# Eval("Name") %&gt;'&gt;&lt;/asp:label&gt; &lt;/td&gt; &lt;td&gt;&lt;asp:button id="btnDelete" runat="server" text="Delete" commandname="Delete"&gt;&lt;/asp:button&gt; &lt;/td&gt; &lt;/tr&gt; &lt;/selecteditemtemplate&gt; &lt;/asp:listview&gt; </code></pre> <p><strong>Binding the File List</strong></p> <p>So currently what happens, is in the <code>TreeView_SelectedNodeChanged</code> event, the application takes the <code>DirectoryInfo</code> object represented by the <code>TreeNode</code> and gets an array of <code>FileInfo</code> objects, using the <code>DirectoryInfo.GetFiles()</code> method.</p> <p>That <code>FileInfo[]</code> is passed to the following method.</p> <pre><code>protected void AddFilesToViewPort(FileInfo[] Files) { List&lt;FileInfo&gt; fList = new List&lt;FileInfo&gt;(); for (int i = 0; i &lt; Files.Length; i++) { fList.Add(Files[i]); } lvFiles.DataSource = fList; lvFiles.DataBind(); upExistingFiles.Update(); } </code></pre> <p>Which binds the <code>FileInfo[]</code> to the <code>ListView</code> object, <code>lvFiles</code>, which is pretty much exactly how I want it.</p> <p>What I want to do is be able to select an item in the ListView (which can be done at the moment) then when the user presses the <code>Delete</code> button, I want the application to work with the file in question. Essentially, I want to move the file to a "Deleted Files" directory and log the action in the database.</p> <p>The problem I'm having is getting the actual <code>FileInfo</code> object associated with the list item I select.</p> <p>If I attach the debugger to the and step through, the <code>lvFiles_ItemDeleting</code> event is firing and I'm getting the index of the selected <code>ListItem</code> as I should be, but when I go through the objects in the debugger, the actual information about the object the <code>ListItem</code> is representing just isn't there.</p> <p><img src="https://i.stack.imgur.com/SwtX8.png" alt="Image showing lack of DataKeys in the debugged ListView"></p> <p>As you can see in the image above, the DataKeys property of the <code>ListView</code> is holding some information about its items, but when I dig deeper into that property, the information just isn't there.</p> <p>How do I get the <code>FileInfo</code> object from the selected <code>ListViewItem</code>?</p>
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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