TreeView Control for Visual Basic 6.0 Users

Artykuł
09/03/2015

The TreeView control in Visual Basic 6.0 is replaced by the TreeView control in Visual Basic 2008. The names of some properties, methods, events, and constants are different, and in some cases there are differences in behavior.

Conceptual Differences

SingleSel Property

In Visual Basic 6.0, the SingleSel property of a TreeView control determines whether a node expands to show its child nodes when selected. Setting this property to True causes the node to expand when selected and causes the previously selected node to contract.

In Visual Basic 2008, the SingleSel property no longer exists. By default, a node does not expand when clicked (the default is equivalent to setting the SingleSel property to False in Visual Basic 6.0). You can use the AfterSelect event to determine when a node has been selected, and then use the Expand or Collapse method to control the expansion behavior.

Image and SelectedImage Properties

In Visual Basic 6.0, it is possible to assign a SelectedImage property to a TreeView control node without assigning an Image property.

In Visual Basic 2008, the TreeNode object of a TreeView control cannot have a SelectedImage property unless it also has an Image property. If you need to emulate Visual Basic 6.0 behavior, you can assign an empty image to the Image property.

Other Differences

In addition, there are numerous conceptual differences that apply to all controls, including differences in data binding, font handling, drag-and-drop operations, Help support, and more. For more information, see Windows Forms Concepts for Visual Basic 6.0 Users.

Code Changes for the TreeView Control

The following examples illustrate differences in coding techniques between Visual Basic 6.0 and Visual Basic 2008.

Code Changes for Expanding a Selected Node in a TreeView Control

The following code demonstrates how to expand a TreeView node when a user selects it.

' Visual Basic 6.0
TreeView1.SingleSel = True

' Visual BasicPrivateSub TreeView1_AfterSelect(ByVal sender AsObject, ByVal e As _
System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect

    TreeView1.SelectedNode.Expand()
EndSub

Code Changes for Adding Nodes in a TreeView Control

The following code demonstrates how to add a new node as a child of the currently selected node.

' Visual Basic 6.0
Dim nodX As Node
Set nodX = TreeView1.Nodes.Add(Node, tvwChild, , "New Node")

' Visual BasicDim nodX As TreeNode = New TreeNode("New Node")
TreeView1.SelectedNode.Nodes.Add(nodX)

TreeView Control Property, Method, and Event Equivalencies

The following tables list Visual Basic 6.0 properties, methods, and events, along with their Visual Basic 2008 equivalents. Those properties, methods, and events that have the same name and behavior are not listed. All Visual Basic 2008 enumerations map to the System.Windows.Forms namespace unless otherwise noted.

This table provides links to topics explaining behavior differences. Where there is no direct equivalent in Visual Basic 2008, links are provided to topics that present alternatives.

Properties

Visual Basic 6.0	Visual Basic 2008 Equivalent
Appearance	New implementation. For more information, see Appearance and BorderStyle Properties for Visual Basic 6.0 Users.
BackColor	BackColor Note: Colors are handled differently in Visual Basic 2008. For more information, see Color Behavior for Visual Basic 6.0 Users.
Container	Parent
DragIcon DragMode	New implementation. For more information, see Drag and Drop for Visual Basic 6.0 Users.
FontFont FontBold FontItalic FontName FontSize FontStrikethrough FontUnderline	Font Note: Fonts are handled differently in Visual Basic 2008. For more information, see Font Object for Visual Basic 6.0 Users.
Height	Height, Size Note: Coordinates are handled differently in Visual Basic 2008. For more information, see Coordinate System for Visual Basic 6.0 Users.
HelpContextID	New implementation. For more information, see Help Support for Visual Basic 6.0 Users.
HWnd	Handle
Indentation	Indent
Index	New implementation. For more information, see Control Arrays for Visual Basic 6.0 Users.
Left	Left Note: Coordinates are handled differently in Visual Basic 2008. For more information, see Coordinate System for Visual Basic 6.0 Users.
LineStyle	ShowRootLines
MouseIcon	New implementation. For more information, see Cannot set a custom MousePointer.
MousePointer	Cursor For a list of constants, see MousePointer for Visual Basic 6.0 Users.
OLEDragMode OLEDropMode	New implementation. For more information, see Drag and Drop for Visual Basic 6.0 Users.
Parent	FindForm method
Scroll	Scrollable
SingleSel	New implementation. Use the NodeMouseClick event.
Style	New implementation property. 0 or Standard maps to the CheckedListBox control, 1 or Checkbox maps to the CheckedListBox control.
ToolTipText	ToolTip component For more information, see ToolTip Support for Visual Basic 6.0 Users.
Top	Top Note: Coordinates are handled differently in Visual Basic 2008. For more information, see Coordinate System for Visual Basic 6.0 Users.
WhatsThisHelpID	New implementation. For more information, see Help Support for Visual Basic 6.0 Users.
Width	Width, Size Note: Coordinates are handled differently in Visual Basic 2008. For more information, see Coordinate System for Visual Basic 6.0 Users.

Methods

Name	Visual Basic 2008 Equivalent
Drag	New implementation. For more information, see Drag and Drop for Visual Basic 6.0 Users.
GetVisibleCount	VisibleCount property.
HitTest	GetNodeAt, GetNodeAt
Move	SetBounds Note: Coordinates are handled differently in Visual Basic 2008. For more information, see Coordinate System for Visual Basic 6.0 Users.
OLEDrag	New implementation. For more information, see Drag and Drop for Visual Basic 6.0 Users.
SetFocus	Focus
ShowWhatsThis	New implementation. For more information, see Help Support for Visual Basic 6.0 Users.
StartLabelEdit	BeginEdit
ZOrder	BringToFront or SendToBack method

Events

Visual Basic 6.0	Visual Basic 2008 Equivalent
Collapse	BeforeCollapse
DblClick	DoubleClick
DragDrop DragOver	New implementation. For more information, see Drag and Drop for Visual Basic 6.0 Users.
Expand	AfterExpand
GotFocus	Enter
LostFocus	Leave
NodeCheck	AfterCheck
NodeClick	NodeMouseClick
OLECompleteDrag OLEDragDrop OLEDragOver OLEGiveFeedback OLESetData OLEStartDrag	New implementation. For more information, see Drag and Drop for Visual Basic 6.0 Users.
Validate	Validating

Upgrade Notes

When a Visual Basic 6.0 project is upgraded to Visual Basic 2008, any TreeView controls are upgraded to Windows Forms TreeView controls. Where properties, methods, and events have no equivalent or have differences in behavior, upgrade notes or warnings are added to your code.

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