Programmatically set handler [WPF]

[CODE]

<TreeView Name="_treeViewMain" TreeViewItem.Selected = "TreeViewItem_Selected">

/CODE]

How I can set the Handler of TreeViewItem.Selected programmatically not using the xaml. Because I need to catch The TreeViewItem as the original source.

Thanks

Code:

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TreeViewItem.Selected += new RoutedEventHandler(TreeViewItem_Selected);

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