TreeView.ShowLines Property
Assembly: System.Windows.Forms (in system.windows.forms.dll)
/** @property */ public boolean get_ShowLines () /** @property */ public void set_ShowLines (boolean value)
public function get ShowLines () : boolean public function set ShowLines (value : boolean)
Property Value
true if lines are drawn between tree nodes in the tree view control; otherwise, false. The default is true.If ShowLines is set to true, the FullRowSelect property is ignored.
The following code example illustrates a customized TreeView. By inheriting the TreeView class, this custom version has all the functionality of a typical TreeView. Changing various property values in the constructor provides a unique appearance. Because the ShowPlusMinus property is set to false, the customized control also overrides the OnAfterSelect method so that nodes can be expanded and collapsed when they are clicked.
A control that is customized in this way can be used throughout an organization, making it easy to provide a consistent interface without requiring the control properties to be specified in each individual project.
public class CustomizedTreeView : TreeView { public CustomizedTreeView() { // Customize the TreeView control by setting various properties. BackColor = System.Drawing.Color.CadetBlue; FullRowSelect = true; HotTracking = true; Indent = 34; ShowPlusMinus = false; // The ShowLines property must be false for the FullRowSelect // property to work. ShowLines = false; } protected override void OnAfterSelect(TreeViewEventArgs e) { // Confirm that the user initiated the selection. // This prevents the first node from expanding when it is // automatically selected during the initialization of // the TreeView control. if (e.Action != TreeViewAction.Unknown) { if (e.Node.IsExpanded) { e.Node.Collapse(); } else { e.Node.Expand(); } } // Remove the selection. This allows the same node to be // clicked twice in succession to toggle the expansion state. SelectedNode = null; } }
public class CustomizedTreeView extends TreeView
{
public CustomizedTreeView()
{
// Customize the TreeView control by setting various properties.
set_BackColor(System.Drawing.Color.get_CadetBlue());
set_FullRowSelect(true);
set_HotTracking(true);
set_Indent(34);
set_ShowPlusMinus(false);
// The ShowLines property must be false for the FullRowSelect
// property to work.
set_ShowLines(false);
} //CustomizedTreeView
protected void OnAfterSelect(TreeViewEventArgs e)
{
// Confirm that the user initiated the selection.
// This prevents the first node from expanding when it is
// automatically selected during the initialization of
// the TreeView control.
if (!(e.get_Action().Equals(TreeViewAction.Unknown))) {
if (e.get_Node().get_IsExpanded()) {
e.get_Node().Collapse();
}
else {
e.get_Node().Expand();
}
}
// Remove the selection. This allows the same node to be
// clicked twice in succession to toggle the expansion state.
set_SelectedNode(null);
} //OnAfterSelect
}//CustomizedTreeView
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.