</ iframe > </noscript> <!-- End Google Tag Manager (noscript) --> <div id="BeforeHeaderContent"> </div> <div id="HeaderContent"> <div id="ProjectTitle">FinancialChart for WPF</div> <div id="PageTitle"><div id="PageTitleText">SelectionChanging Event</div></div> </div> <div id="AfterHeaderContent"> <!-- Spacing --> <span id="ToggleAllSectionsLink" class="FunctionLink"> <label id="CollapseAllLabel">Collapse All</label> <label id="ExpandAllLabel" style="display: none;">Expand All</label> </span><!-- Spacing --> <span id="LanguageFilterPopupLink" class="PopupLink" data-popupcontentsource="#LanguageCheckboxes" data-popuptitle="Language Filter"> <label id="ShowAllLabel" for="LanguageFilterPopupLink"> Language Filter: All </label> <label id="MultipleLabel" for="LanguageFilterPopupLink" style="display: none;"> Language Filter: Multiple </label> <label id="VBAllLabel" for="LanguageFilterPopupLink" style="display: none;"> Language Filter: Visual Basic </label> <label id="VBLabel" for="LanguageFilterPopupLink" style="display: none;">Language Filter: Visual Basic (Declaration)</label> <label id="VBUsageLabel" for="LanguageFilterPopupLink" style="display: none;">Language Filter: Visual Basic (Usage)</label> <label id="CSLabel" for="LanguageFilterPopupLink" style="display: none;">Language Filter: C#</label> <label id="CPP2005Label" for="LanguageFilterPopupLink" style="display: none;">Language Filter: C++/CLI</label> </span> <div class="PopupContent" id="LanguageCheckboxes"> <input data-languagename="VB" id="VBLanguageCheckbox" type="checkbox" class="ToggleLanguageCheckbox" checked="true" data-toggleclass="FilteredContentVB"> <label class="LanguageFilter" for="VBCheckbox"> Visual Basic (Declaration) </label> <br><input data-languagename="VBUsage" id="VBUsageLanguageCheckbox" type="checkbox" class="ToggleLanguageCheckbox" checked="true" data-toggleclass="FilteredContentVBUsage"> <label class="LanguageFilter" for="VBUsageCheckbox"> Visual Basic (Usage) </label> <br><input data-languagename="CS" id="CSLanguageCheckbox" type="checkbox" class="ToggleLanguageCheckbox" checked="true" data-toggleclass="FilteredContentCS"> <label class="LanguageFilter" for="CSCheckbox"> C# </label> <br><input data-languagename="CPP2005" id="CPP2005LanguageCheckbox" type="checkbox" class="ToggleLanguageCheckbox" checked="true" data-toggleclass="FilteredContentCPP2005"> <label class="LanguageFilter" for="CPP2005Checkbox"> C++/CLI </label> </div> </div> <div class="BreadcrumbsContainer"><table><tbody><tr><td> <a href="C1.WPF.4~C1.WPF_namespace.html">C1.WPF Namespace</a> > <a href="C1.WPF.4~C1.WPF.C1TreeView.html">C1TreeView Class</a> : SelectionChanging Event</td></tr></tbody></table></div> <div id="BodyContent"> <div class="DescriptionContent">Occurs when the current selection begin to change.</div> <div class="SectionHeading" id="syntaxSectionHeading"><span class="SectionHeadingIcon"><!-- --></span><span class="SectionHeadingText">Syntax</span></div><div id="syntaxSectionContent" class="SectionContent"> <div class="TabContainer ui-tabs ui-widget ui-widget-content ui-corner-all" id="TabContainer"> <ul class="ui-tabs-nav ui-helper-reset ui-helper-clearfix ui-widget-header ui-corner-all"> <li class="FilteredContentVBAll ui-state-default ui-corner-top ui-tabs-selected ui-state-active"><a href="#Syntax-VBAll">Visual Basic</a></li> <li class="FilteredContentCS ui-state-default ui-corner-top"><a href="#Syntax-CS">C#</a></li> <li class="FilteredContentCPP2005 ui-state-default ui-corner-top"><a href="#Syntax-CPP2005">C++/CLI</a></li> </ul> <div id="Syntax-CS" class="FilteredContentCS ui-tabs-panel ui-widget-content ui-corner-bottom ui-tabs-hide"> <pre><pre><span style="color: #0000FF; ">public</span> <span style="color: #0000FF; ">event</span> <a href="C1.WPF.4~C1.WPF.SelectionChangingEventHandler.html">SelectionChangingEventHandler</a> SelectionChanging</pre></pre> </div> <div id="Syntax-CPP2005" class="FilteredContentCPP2005 ui-tabs-panel ui-widget-content ui-corner-bottom ui-tabs-hide"> <pre><pre><span style="color: #0000FF; ">public</span>: <span style="color: #0000FF; ">event</span> <a href="C1.WPF.4~C1.WPF.SelectionChangingEventHandler.html">SelectionChangingEventHandler^</a> SelectionChanging</pre></pre> </div> <div id="Syntax-VBAll" class="ui-tabs-panel ui-widget-content ui-corner-bottom"><div id="Syntax-VB" class="FilteredContentVB"> <pre><pre><span style="color: #008000; ">'Declaration </span> </pre><pre><span style="color: #0000FF; ">Public</span> <span style="color: #0000FF; ">Event</span> SelectionChanging <span style="color: #0000FF; ">As</span> <a href="C1.WPF.4~C1.WPF.SelectionChangingEventHandler.html">SelectionChangingEventHandler</a></pre></pre> </div> <div id="Syntax-VBUsage" class="FilteredContentVBUsage"> <pre><pre><span style="color: #008000; ">'Usage </span> </pre><pre><span style="color: #0000FF; ">Dim</span> instance <span style="color: #0000FF; ">As</span> <a href="C1.WPF.4~C1.WPF.C1TreeView.html">C1TreeView</a> <span style="color: #0000FF; ">Dim</span> handler <span style="color: #0000FF; ">As</span> <a href="C1.WPF.4~C1.WPF.SelectionChangingEventHandler.html">SelectionChangingEventHandler</a> <span style="color: #0000FF; ">AddHandler</span> instance.SelectionChanging, handler</pre></pre> </div></div></div> </div> <div class="SectionHeading" id="exceptionsSectionHeading"><span class="SectionHeadingIcon"><!-- --></span><span class="SectionHeadingText">Event Data</span></div><div id="exceptionsSectionContent" class="SectionContent"><p>The event handler receives an argument of type <a href="C1.WPF.4~C1.WPF.SelectionChangingEventArgs.html">SelectionChangingEventArgs</a> containing data related to this event. The following <b>SelectionChangingEventArgs</b> properties provide information specific to this event.</p><table class="FilteredItemListTable"><tbody><tr><th>Property</th><th>Description</th></tr><tr><td class="LinkCell"><a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsControlsSelectionChangedEventArgsClassAddedItemsTopic','System.Windows.Controls.SelectionChangedEventArgs.AddedItems')">AddedItems</a></td><td class="DescriptionCell"> (Inherited from <a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsControlsSelectionChangedEventArgsClassTopic','System.Windows.Controls.SelectionChangedEventArgs')">System.Windows.Controls.SelectionChangedEventArgs</a>)</td></tr><tr><td class="LinkCell"><a href="C1.WPF.4~C1.WPF.SelectionChangingEventArgs~Cancel.html">Cancel</a></td><td class="DescriptionCell">Cancel the Selection operation. </td></tr><tr><td class="LinkCell"><a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassHandledTopic','System.Windows.RoutedEventArgs.Handled')">Handled</a></td><td class="DescriptionCell"> (Inherited from <a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassTopic','System.Windows.RoutedEventArgs')">System.Windows.RoutedEventArgs</a>)</td></tr><tr><td class="LinkCell"><a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassOriginalSourceTopic','System.Windows.RoutedEventArgs.OriginalSource')">OriginalSource</a></td><td class="DescriptionCell"> (Inherited from <a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassTopic','System.Windows.RoutedEventArgs')">System.Windows.RoutedEventArgs</a>)</td></tr><tr><td class="LinkCell"><a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsControlsSelectionChangedEventArgsClassRemovedItemsTopic','System.Windows.Controls.SelectionChangedEventArgs.RemovedItems')">RemovedItems</a></td><td class="DescriptionCell"> (Inherited from <a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsControlsSelectionChangedEventArgsClassTopic','System.Windows.Controls.SelectionChangedEventArgs')">System.Windows.Controls.SelectionChangedEventArgs</a>)</td></tr><tr><td class="LinkCell"><a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassRoutedEventTopic','System.Windows.RoutedEventArgs.RoutedEvent')">RoutedEvent</a></td><td class="DescriptionCell"> (Inherited from <a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassTopic','System.Windows.RoutedEventArgs')">System.Windows.RoutedEventArgs</a>)</td></tr><tr><td class="LinkCell"><a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassSourceTopic','System.Windows.RoutedEventArgs.Source')">Source</a></td><td class="DescriptionCell"> (Inherited from <a href="#" onclick="javascript:navigateToHelp2Keyword('frlrfSystemWindowsRoutedEventArgsClassTopic','System.Windows.RoutedEventArgs')">System.Windows.RoutedEventArgs</a>)</td></tr></tbody></table></div> <a name="exampleBookmark"></a> <div class="SectionHeading" id="requirementsSectionHeading"><span class="SectionHeadingIcon"><!-- --></span><span class="SectionHeadingText">Requirements</span></div><div id="requirementsSectionContent" class="SectionContent"><p><b>Target Platforms:</b> Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2</p></div> <a name="seealsobookmark"></a> <div class="SectionHeading" id="seealsoSectionHeading"><span class="SectionHeadingIcon"><!-- --></span><span class="SectionHeadingText">See Also</span></div><div id="seealsoSectionContent" class="SectionContent"><h4 class="subHeading">Reference</h4><p><a href="C1.WPF.4~C1.WPF.C1TreeView.html">C1TreeView Class</a> <br><a href="C1.WPF.4~C1.WPF.C1TreeView_members.html">C1TreeView Members</a> </p> </div> </div> <div id="FooterContent"> <p> </p><p> </p><hr style="height: 1px"><p>Copyright © <script type="text/javascript"> var theDate=new Date() document.write(theDate.getFullYear()) </script>2025 GrapeCity, inc. 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