304 lines
12 KiB
HTML
304 lines
12 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|||
|
|
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xlink="http://www.w3.org/1999/xlink">
|
|||
|
|
<head>
|
|||
|
|
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
|
|||
|
|
<title>Performance</title>
|
|||
|
|
<link href="style.css" rel="stylesheet" type="text/css">
|
|||
|
|
<link href="prettify.css" type="text/css" rel="stylesheet">
|
|||
|
|
<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">
|
|||
|
|
</head>
|
|||
|
|
<body onload="prettyPrint()"><div class="placing">
|
|||
|
|
<br><table class="navigation"><tr>
|
|||
|
|
<td class="navigation-previous"><a href="chapter-owner-draw.html"><strong>
|
|||
|
|
« Owner Drawing</strong></a></td>
|
|||
|
|
<td class="navigation-index"><a href="../../../quick-start-guide/better-listview/index.html"><strong>Index</strong></a></td>
|
|||
|
|
<td class="navigation-next"><a href="chapter-save-load.html"><strong>Saving and Loading ListView Content »
|
|||
|
|
</strong></a></td>
|
|||
|
|
</tr></table>
|
|||
|
|
<br><h1>Performance</h1>
|
|||
|
|
<div class="banner">
|
|||
|
|
<a href="../../../blog/page/6/index.html"><img src="../resources/overview.gif" alt="Better ListView" class="ss"></a>
|
|||
|
|
<div class="inside">
|
|||
|
|
<div class="text">Better ListView: Ultimate .NET ListView replacement control for WinForms (C#, VB.NET)</div>
|
|||
|
|
<span class="dbtn-c dbtn-hilight"><span class="dbtn-w"><a href="../../../betterlistview.exe" class="dbtn">Download</a></span></span>
|
|||
|
|
<span class="dbtn-c"><span class="dbtn-w"><a href="../../../blog/page/6/index.html" class="dbtn">More Info</a></span></span>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>
|
|||
|
|
<a name="beginupdate-endupdate" id="beginupdate-endupdate"></a>Using BeginUpdate and
|
|||
|
|
EndUpdate</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>When doing several operations with Better ListView at a time, these
|
|||
|
|
operations should be enclosed in BeginUpdate and EndUpdate method
|
|||
|
|
calls.</p>
|
|||
|
|
|
|||
|
|
<p>For example:</p>
|
|||
|
|
|
|||
|
|
<p><strong>C#</strong></p>
|
|||
|
|
<pre class="prettyprint"><code class="lang-cs">listView.BeginUpdate();
|
|||
|
|
|
|||
|
|
for (int i = 0; i < 100; i++)
|
|||
|
|
{
|
|||
|
|
listView.Items.Add(String.Format("Item no. {0}", i));
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
listView.EndUpdate();</code></pre>
|
|||
|
|
|
|||
|
|
<p><strong>Visual Basic</strong></p>
|
|||
|
|
<pre class="prettyprint"><code class="lang-vb">ListView.BeginUpdate()
|
|||
|
|
|
|||
|
|
For i As Integer = 0 To 99
|
|||
|
|
ListView.Items.Add([String].Format("Item no. {0}", i))
|
|||
|
|
Next
|
|||
|
|
|
|||
|
|
listView.EndUpdate()</code></pre>
|
|||
|
|
|
|||
|
|
<p>Without these methods, Better ListView would refresh itself 100
|
|||
|
|
times and the whole operation would take noticeable time. The same applies
|
|||
|
|
to setting properties or modifying other collections (column headers,
|
|||
|
|
sub-items, child items, groups) so it is still convenient to use
|
|||
|
|
<span class="code">BeginUpdate</span> and <span class="code">EndUpdate</span> when setting multiple
|
|||
|
|
properties:</p>
|
|||
|
|
|
|||
|
|
<p><strong>C#</strong></p>
|
|||
|
|
<pre class="prettyprint"><code class="lang-cs">BeginUpdate();
|
|||
|
|
|
|||
|
|
listView.Items[0].SubItems[1].Align = TextAlignment.Right;
|
|||
|
|
|
|||
|
|
listView.MultiSelect = true;
|
|||
|
|
listView.CheckBoxes = BetterListViewCheckBoxes.TwoState;
|
|||
|
|
|
|||
|
|
EndUpdate();</code></pre>
|
|||
|
|
|
|||
|
|
<p><strong>Visual Basic</strong></p>
|
|||
|
|
<pre class="prettyprint"><code class="lang-vb">BeginUpdate()
|
|||
|
|
|
|||
|
|
ListView.Items(0).SubItems(1).Align = TextAlignment.Right
|
|||
|
|
|
|||
|
|
ListView.MultiSelect = True
|
|||
|
|
ListView.CheckBoxes = BetterListViewCheckBoxes.TwoState
|
|||
|
|
|
|||
|
|
EndUpdate()</code></pre>
|
|||
|
|
|
|||
|
|
<p>There can be multiple calls of <span class="code">BeginUpdate</span> and the
|
|||
|
|
control will actually refresh after the same number of
|
|||
|
|
<span class="code">EndUpdate</span> calls are made.</p>
|
|||
|
|
|
|||
|
|
<p>It is also possible to call <span class="code">EndUpdate</span> with boolean
|
|||
|
|
parameter. The call <span class="code">EndUpdate(true)</span> will avoid refreshing the
|
|||
|
|
control, but still move the control out of the updation state.</p>
|
|||
|
|
|
|||
|
|
<p>To check whether the control is in updation state, use the
|
|||
|
|
<span class="code">IsUpdating</span> property:</p>
|
|||
|
|
|
|||
|
|
<p><strong>C#</strong></p>
|
|||
|
|
<pre class="prettyprint"><code class="lang-cs">// intentionally call BeginUpdate twice
|
|||
|
|
BeginUpdate();
|
|||
|
|
BeginUpdate();
|
|||
|
|
|
|||
|
|
// listView.IsUpdating is true
|
|||
|
|
|
|||
|
|
EndUpdate();
|
|||
|
|
|
|||
|
|
// still updating, listView.IsUpdating is true
|
|||
|
|
|
|||
|
|
EndUpdate();
|
|||
|
|
|
|||
|
|
// still updating, listView.IsUpdating is false</code></pre>
|
|||
|
|
|
|||
|
|
<p><strong>Visual Basic</strong></p>
|
|||
|
|
<pre class="prettyprint"><code class="lang-vb">' intentionally call BeginUpdate twice
|
|||
|
|
BeginUpdate()
|
|||
|
|
BeginUpdate()
|
|||
|
|
|
|||
|
|
' listView.IsUpdating is true
|
|||
|
|
|
|||
|
|
EndUpdate()
|
|||
|
|
|
|||
|
|
' still updating, listView.IsUpdating is true
|
|||
|
|
|
|||
|
|
EndUpdate()
|
|||
|
|
|
|||
|
|
' still updating, listView.IsUpdating is false</code></pre>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Performance of Image versus ImageList</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>There are two ways of setting images to Better ListView elements:
|
|||
|
|
<span class="code">Image</span> property and <span class="code">ImageList</span> property.</p>
|
|||
|
|
|
|||
|
|
<p><span class="code">ImageList</span> is convenient when you want to use images
|
|||
|
|
which are not attached directly to elements (the element - e.g. item -
|
|||
|
|
only refers to image index or key within the global image list). The
|
|||
|
|
performance of <span class="code">ImageList</span>, however, is quite slow. The
|
|||
|
|
slowness can be painful in some critical cases, like column
|
|||
|
|
resizing.</p>
|
|||
|
|
|
|||
|
|
<p>When working with many items, we recommend using <span class="code">Image</span>
|
|||
|
|
property instead.</p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Performance Properties</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>Better ListView was designed to be responsive to user although it is
|
|||
|
|
quite complex control. It is sometimes convenient to adjust optimization
|
|||
|
|
settings. This can be done through the following properties:</p>
|
|||
|
|
|
|||
|
|
<ul style="list-style:none">
|
|||
|
|
<li>
|
|||
|
|
<span class="code">BetterListView.AutoSizeItemsInDetailsView</span><ul style="list-style:none"><li>
|
|||
|
|
<p><span class="code">false</span> by default</p>
|
|||
|
|
</li></ul>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<span class="code">BetterListView.CacheImages</span><ul style="list-style:none"><li>
|
|||
|
|
<p><span class="code">true</span> by default</p>
|
|||
|
|
</li></ul>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<span class="code">BetterListView.MaximumToolTipTextLength</span><ul style="list-style:none"><li>
|
|||
|
|
<p><span class="code">1000</span> by default</p>
|
|||
|
|
</li></ul>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<span class="code">BetterListView.OptimizedInvalidation</span><ul style="list-style:none"><li>
|
|||
|
|
<p><span class="code">true</span> by default</p>
|
|||
|
|
</li></ul>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<span class="code">BetterListViewColumnHeader.SmoothColumnResize</span><ul style="list-style:none"><li>
|
|||
|
|
<p><span class="code">true</span> by default. Can be set on each column header
|
|||
|
|
separately.</p>
|
|||
|
|
</li></ul>
|
|||
|
|
</li>
|
|||
|
|
<li>
|
|||
|
|
<span class="code">BetterListView.SortOnCollectionChange</span><ul style="list-style:none"><li>
|
|||
|
|
<p><span class="code">true</span> by default</p>
|
|||
|
|
</li></ul>
|
|||
|
|
</li>
|
|||
|
|
</ul>
|
|||
|
|
<h2>Automatic Resizing of Items in Details View</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>Better ListView supports displaying items in
|
|||
|
|
<strong><em>Details</em></strong> view even when there are no columns. When
|
|||
|
|
columns are displayed, item width is determined by the total width of all
|
|||
|
|
columns. When columns are not present, items have fixed width by default.
|
|||
|
|
By settings <span class="code">AutoSizeItemsInDetailsView</span> property to
|
|||
|
|
<span class="code">true</span>, items will be always stretched to client area width.
|
|||
|
|
The following images shows item size without and with automatic
|
|||
|
|
resizing:</p>
|
|||
|
|
|
|||
|
|
<p class="images"><img src="performance-autosizeitemsindetailsview1.png"></p>
|
|||
|
|
|
|||
|
|
<p class="images"><img src="performance-autosizeitemsindetailsview2.png"></p>
|
|||
|
|
|
|||
|
|
<p>Items are not resized by default, because it slows performance when
|
|||
|
|
Better ListView contains huge number of items.</p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Image Caching</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>When Better ListView contains images of various sizes which are
|
|||
|
|
possibly downscaled, its performance can drop. Showing image frames and
|
|||
|
|
shadows can slow down redrawing of the control even more. When
|
|||
|
|
<span class="code">CacheImages</span> property is set to <span class="code">true</span>, Better
|
|||
|
|
ListView downscales every image just once and then stores the scaled image
|
|||
|
|
(also with its frame) to internal cache. The scaled image is then
|
|||
|
|
displayed quickly.</p>
|
|||
|
|
|
|||
|
|
<p>The cache is cleared whenever an item property si changed affecting
|
|||
|
|
image or its border.</p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Optimized Invalidation</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>When user moves mouse cursor over the control, not all the elements
|
|||
|
|
have to be redrawn. For example, when user moves mouse cursor from column
|
|||
|
|
header A to item B, hot state of these elements changes and only these two
|
|||
|
|
elements are be redrawn. Optimized invalidation finds always the smallest
|
|||
|
|
region to redraw.</p>
|
|||
|
|
|
|||
|
|
<p>This behavior is used when <span class="code">OptimizedInvalidation</span>
|
|||
|
|
property is set to <span class="code">true</span>. This behavior can be sometimes
|
|||
|
|
unwanted, e.g. on some specific <strong><em><a href="chapter-owner-draw.html">Owner drawing</a></em></strong>.</p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Smooth Column Resizing</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>When columns are resized in <strong><em>Details</em></strong> view, the
|
|||
|
|
items and sub-items are resized as well. Item resizing may pose a
|
|||
|
|
performance bottleneck, when there are huge number of items present and
|
|||
|
|
column resizing animation may not be smooth. It is possible to set
|
|||
|
|
<span class="code">BetterListViewColumnHeader.SmoothColumnResize</span> property to
|
|||
|
|
<span class="code">false</span>, which will cause items and sub-items in the specific
|
|||
|
|
column to be resized only once: when column resizing is finished (e.g.
|
|||
|
|
when user releases mouse button).</p>
|
|||
|
|
|
|||
|
|
<p>When the smooth column resizing feature is turned off, a line is
|
|||
|
|
displayed that shows new column width:</p>
|
|||
|
|
|
|||
|
|
<p class="images"><img src="performance-smoothcolumnresize.png"></p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Sorting on Collection Change</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>When the Better ListView is sorted and its content is changed, it
|
|||
|
|
keeps sort order by default. This needs, however, to re-sort all the items
|
|||
|
|
whenever there is some change.</p>
|
|||
|
|
|
|||
|
|
<p>This behavior can be turned off by settings
|
|||
|
|
<span class="code">SortOnCollectionChanged</span> property to <span class="code">false</span>. In
|
|||
|
|
that case, Better ListView does not guarantee that the Items collection is
|
|||
|
|
always sorted and you have to perform sorting manually, when
|
|||
|
|
needed.</p>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<h2>Maximum ToolTip Text Length</h2>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<p>The property <span class="code">MaximumToolTipTextLength</span> limits the
|
|||
|
|
maximum allowed length of text within automatic tooltips. When element
|
|||
|
|
text is very long, it may take a long time for a tooltip to
|
|||
|
|
display.</p>
|
|||
|
|
|
|||
|
|
<p>When the element text is too long, it is shortened to length of
|
|||
|
|
(<span class="code">MaximumToolTipTextLength - 1</span>) and an ellipsis character is
|
|||
|
|
added at the end of the text.</p>
|
|||
|
|
|
|||
|
|
<br><div class="banner">
|
|||
|
|
<a href="../../../blog/page/6/index.html"><img src="../resources/overview.gif" alt="Better ListView" class="ss"></a>
|
|||
|
|
<div class="inside">
|
|||
|
|
<div class="text">Better ListView: Ultimate .NET ListView replacement control for WinForms (C#, VB.NET)</div>
|
|||
|
|
<span class="dbtn-c dbtn-hilight"><span class="dbtn-w"><a href="../../../betterlistview.exe" class="dbtn">Download</a></span></span>
|
|||
|
|
<span class="dbtn-c"><span class="dbtn-w"><a href="../../../blog/page/6/index.html" class="dbtn">More Info</a></span></span>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<table class="navigation"><tr>
|
|||
|
|
<td class="navigation-previous"><a href="chapter-owner-draw.html"><strong>
|
|||
|
|
« Owner Drawing</strong></a></td>
|
|||
|
|
<td class="navigation-index"><a href="../../../quick-start-guide/better-listview/index.html"><strong>Index</strong></a></td>
|
|||
|
|
<td class="navigation-next"><a href="chapter-save-load.html"><strong>Saving and Loading ListView Content »
|
|||
|
|
</strong></a></td>
|
|||
|
|
</tr></table>
|
|||
|
|
<br><table class="footer"><tr>
|
|||
|
|
<td class="footer-title">Better ListView Documentation
|
|||
|
|
</td>
|
|||
|
|
<td class="footer-copyright">
|
|||
|
|
Copyright © 2010-2012 <a href="../../../index.html" target="_blank">ComponentOwl.com</a>
|
|||
|
|
</td>
|
|||
|
|
</tr></table>
|
|||
|
|
</div></body>
|
|||
|
|
</html>
|