300 lines
11 KiB
HTML
300 lines
11 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xlink="http://www.w3.org/1999/xlink">
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<head>
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<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
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<title>Item Hierarchy</title>
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<link href="style.css" rel="stylesheet" type="text/css">
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<link href="prettify.css" type="text/css" rel="stylesheet">
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<script type="text/javascript" src="prettify.js"></script><script type="text/javascript" src="lang-vb.js"></script><link href="../resources/main.css" media="screen" rel="stylesheet" type="text/css">
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</head>
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<body onload="prettyPrint()"><div class="placing">
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<br><table class="navigation"><tr>
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<td class="navigation-previous"><a href="chapter-insertion-mark.html"><strong>
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« Insertion Mark</strong></a></td>
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<td class="navigation-index"><a href="../../../quick-start-guide/better-listview/index.html"><strong>Index</strong></a></td>
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<td class="navigation-next"><a href="chapter-item-reorder.html"><strong>Item Reordering »
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</strong></a></td>
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</tr></table>
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<br><h1>Item Hierarchy</h1>
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<div class="banner">
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<a href="../../../blog/page/6/index.html"><img src="../resources/overview.gif" alt="Better ListView" class="ss"></a>
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<div class="inside">
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<div class="text">Better ListView: Ultimate .NET ListView replacement control for WinForms (C#, VB.NET)</div>
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<span class="dbtn-c dbtn-hilight"><span class="dbtn-w"><a href="../../../betterlistview.exe" class="dbtn">Download</a></span></span>
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<span class="dbtn-c"><span class="dbtn-w"><a href="../../../blog/page/6/index.html" class="dbtn">More Info</a></span></span>
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</div>
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</div>
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<p>Items can be organized in tree structure by using
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<span class="code">BetterListViewItem.ChildItems</span> collection. Simply add items as
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other item's children to create a parent-child relationship:</p>
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<p class="images"><img src="item-hierarchy-overview.png"></p>
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<p>Hierarchical items can be used in combination with columns and <strong><em><a href="chapter-groups.html">Groups</a></em></strong>:</p>
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<p class="images"><img src="item-hierarchy-groups.png"></p>
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<p>Child items can use sub-items as well.</p>
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<p>Parent items can be collapsed and expanded through expand buttons.
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Expand buttons appear automatically when there are any children. Expand
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buttons can be disabled on all items using
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<span class="code">ShowItemExpandButtons</span> property or individually using
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<span class="code">BetterListViewItem.AllowShowExpandButton</span>.</p>
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<h2>Unselecting Collapsed Items</h2>
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<p>When both parent and child items are selected and the parent item is
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collapsed, you may want to unselect the child items and/or select the
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parent item. There is a <span class="code">CollapsedItemUnselection</span> poperty for
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setting up this behavior. It has one of the following values:</p>
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<ul style="list-style:none">
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<li>DoNothing<ul style="list-style:none"><li>
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<p>No action is performed when items are unselected.</p>
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</li></ul>
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</li>
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<li>UnselectOnly<ul style="list-style:none"><li>
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<p>Child items are unselected.</p>
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</li></ul>
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</li>
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<li>SelectParent<ul style="list-style:none"><li>
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<p>Child items are unselected and the parent item is
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selected.</p>
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</li></ul>
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</li>
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</ul>
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<h2>Adjusting Indentation</h2>
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<p>By default, the child items have indentation of an expand button
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size. Indentation can be adjusted by settings <span class="code">Indent</span> property
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to any non-negative value (the indentation unit is pixels). To resume
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default indentation, set the property to
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<span class="code">BetterListView.DefaultIndent</span>. Following images show effect of
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different indentation:</p>
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<p class="images"><img src="item-hierarchy-indent-small.png"><img src="item-hierarchy-indent-large.png"></p>
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<h2>Traversing Hierarchical Items</h2>
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<p><span class="code">BetterListViewItem</span> implements <span class="code">IEnumerable</span>
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interface to allow traversing through all its child items in a foreach
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cycle:</p>
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<p><strong>C#</strong></p>
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<pre class="prettyprint"><code class="lang-cs">foreach (BetterListViewItem itemChild in items)
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{
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// ...
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}</code></pre>
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<p><strong>Visual Basic</strong></p>
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<pre class="prettyprint"><code class="lang-vb">For Each itemChild As BetterListViewItem In items
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' ...
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Next</code></pre>
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<p>The same is possible on whole <span class="code">BetterListView</span>; it also
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implements <span class="code">IEnumerable</span> to enumerate all items within the
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list, including child items.</p>
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<h2>Navigation in Hierarchy</h2>
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<p>Multiple levels of hierarchy are possible.
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<span class="code">BetterListViewItem</span> has following properties for easy
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navigation in item hierarchy:</p>
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<ul style="list-style:none">
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<li>
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<span class="code">Address</span><ul style="list-style:none"><li>
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<p>Location of the item within hierarchy.</p>
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</li></ul>
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</li>
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<li>
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<span class="code">ChildItems</span><ul style="list-style:none"><li>
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<p>Child items of the item.</p>
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</li></ul>
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</li>
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<li>
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<span class="code">LastAvailableChildItem</span><ul style="list-style:none"><li>
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<p>The last (bottom) child item that can be scrolled into
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view.</p>
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</li></ul>
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</li>
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<li>
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<span class="code">Level</span><ul style="list-style:none"><li>
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<p>Item level in hierarchy (the top level is 0).</p>
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</li></ul>
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</li>
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<li>
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<span class="code">ParentItem</span><ul style="list-style:none"><li>
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<p>Parent item of the item (one level up).</p>
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</li></ul>
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</li>
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</ul>
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<h2>
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<a name="addressing-elements" id="addressing-elements"></a>Addressing Elements</h2>
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<p>Since Better ListView supports <strong><em><a href="chapter-item-hierarchy.html">Hierarchical items</a></em></strong> there
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is a need for addressing items on different levels of hierarchy. When
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using only the Items list, <span class="code">BetterListViewItem.Index</span> property
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is sufficient. Child items (contained in
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<span class="code">BetterListViewItem.ChildItems </span>collection) has its own
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indices, so there can be several items with <span class="code">Index</span> property
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equal to <span class="code">0</span>, for example. To localize every element (item or
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group) uniquely, use the <span class="code">Address</span> property:</p>
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<ul>
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<li>
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<p><span class="code">BetterListViewGroup.Address</span></p>
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</li>
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<li>
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<p><span class="code">BetterListViewItem.Address</span></p>
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</li>
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</ul>
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<p>Address is a structure that can be represented as string (via
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<span class="code">ToString</span> method) or parsed from such string. Element address
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looks like this:</p>
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<pre>5:7.3</pre>
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<p>The first number followed by colon (prefix) is a group index. The
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rest of numbers represent indices of items and child items separated by
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periods (in this case: <strong><em>item with index 3, which is a child item
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of item with index 7</em></strong>).</p>
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<p>If there are no groups, the prefix is not present.</p>
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<p><span class="code">BetterListViewAddress</span> structure implements
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<span class="code">IComparable</span>, so the two addresses can be compared. Element
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that is displayed above other element in Better ListView has always lower
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address value. Addresses can also be compared using operators
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<span class="code"><</span>, <span class="code">></span>, <span class="code"><=</span> and
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<span class="code">>=</span>.</p>
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<h2>Get Item/Group for the Given Address</h2>
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<p>There are two methods for retrieving items and groups for the given
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address:</p>
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<ul>
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<li>
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<p><span class="code">GetGroupFromAddress(BetterListViewAddress)</span></p>
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</li>
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<li>
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<p><span class="code">GetItemFromAddress(BetterListViewAddress)</span></p>
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</li>
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</ul>
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<h2>Sample Source Code</h2>
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<p><strong>C#</strong></p>
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<pre class="prettyprint"><code class="lang-cs">this.listView.BeginUpdate();
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this.listView.Columns.Add("Documents", 256);
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// create first top-level item
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BetterListViewItem itemAudio = new BetterListViewItem("Audio Files");
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// add children to the first top-level item
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itemAudio.ChildItems.AddRange(
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new[]
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{
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new BetterListViewItem("Call with Josh (2011-10-6).mp3"),
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new BetterListViewItem("Great Ringtone.mp3")
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});
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// create second top-level item
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BetterListViewItem itemVideo = new BetterListViewItem("Video Files");
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// add children to the second top-level item
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itemVideo.ChildItems.AddRange(
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new[]
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{
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new BetterListViewItem("Annual Conference.avi")
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});
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// add the top-level items to list
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// NOTE: children are added automatically
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this.listView.Items.AddRange(
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new[]
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{
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itemAudio,
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itemVideo
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});
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this.listView.EndUpdate();</code></pre>
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<p><strong>Visual Basic</strong></p>
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<pre class="prettyprint"><code class="lang-vb">' Add any initialization after the InitializeComponent() call.
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ListView.BeginUpdate()
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ListView.Columns.Add ("Documents", 256)
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' create first top-level item
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Dim itemAudio As New BetterListViewItem ("Audio Files")
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' add children to the first top-level item
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itemAudio.ChildItems.AddRange (
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New BetterListViewItem() { _
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New BetterListViewItem ("Call with Josh (2011-10-6).mp3"),
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New BetterListViewItem ("Great Ringtone.mp3")
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})
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' create second top-level item
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Dim itemVideo As New BetterListViewItem ("Video Files")
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' add children to the second top-level item
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itemVideo.ChildItems.AddRange (
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New BetterListViewItem() { _
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New BetterListViewItem ("Annual Conference.avi")
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})
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' add the top-level items to list
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' NOTE: children are added automatically
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ListView.Items.AddRange (
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New BetterListViewItem() { _
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itemAudio,
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itemVideo
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})
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ListView.EndUpdate()</code></pre>
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<br><div class="banner">
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<a href="../../../blog/page/6/index.html"><img src="../resources/overview.gif" alt="Better ListView" class="ss"></a>
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<div class="inside">
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||
<div class="text">Better ListView: Ultimate .NET ListView replacement control for WinForms (C#, VB.NET)</div>
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<span class="dbtn-c dbtn-hilight"><span class="dbtn-w"><a href="../../../betterlistview.exe" class="dbtn">Download</a></span></span>
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||
<span class="dbtn-c"><span class="dbtn-w"><a href="../../../blog/page/6/index.html" class="dbtn">More Info</a></span></span>
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</div>
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||
</div>
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<table class="navigation"><tr>
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<td class="navigation-previous"><a href="chapter-insertion-mark.html"><strong>
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« Insertion Mark</strong></a></td>
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<td class="navigation-index"><a href="../../../quick-start-guide/better-listview/index.html"><strong>Index</strong></a></td>
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<td class="navigation-next"><a href="chapter-item-reorder.html"><strong>Item Reordering »
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</strong></a></td>
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</tr></table>
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<br><table class="footer"><tr>
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<td class="footer-title">Better ListView Documentation
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</td>
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<td class="footer-copyright">
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Copyright © 2010-2012 <a href="../../../index.html" target="_blank">ComponentOwl.com</a>
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</td>
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</tr></table>
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</div></body>
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</html>
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