TriState-TreeView
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Hi, ich habe einfach den Source aus dem 1. Link meines vorherigen Posts genommen und nach vb.net konvertiert.
' Copyright (CPOL) 2011 RikTheVeggie - see http://www.codeproject.com/info/cpol10.aspx ' Tri-State Tree View http://www.codeproject.com/script/Articles/ViewDownloads.aspx?aid=202435 ' <summary> ' A Tri-State TreeView designed for on-demand populating of the tree ' </summary> ' <remarks> ' 'Mixed' nodes retain their checked state, meaning they can be checked or unchecked according to their current state ' Tree can be navigated by keyboard (cursor keys & space) ' No need to do anything special in calling code ' </remarks> Public Class TriStateTreeView Inherits System.Windows.Forms.TreeView ' <remarks> ' CheckedState is an enum of all allowable nodes states ' </remarks> Public Enum CheckedState As Integer UnInitialised = -1 UnChecked Checked Mixed End Enum ' <remarks> ' IgnoreClickAction is used to ingore messages generated by setting the node.Checked flag in code ' Do not set <c>e.Cancel = true</c> in <c>OnBeforeCheck</c> otherwise the Checked state will be lost ' </remarks> Private IgnoreClickAction As Integer = 0 ' <remarks> ' TriStateStyles is an enum of all allowable tree styles ' All styles check children when parent is checked ' Installer automatically checks parent if all children are checked, and unchecks parent if at least one child is unchecked ' Standard never changes the checked status of a parent ' </remarks> Public Enum TriStateStyles As Integer Standard = 0 Installer End Enum ' Create a private member for the tree style, and allow it to be set on the property sheer Private TriStateStyle As TriStateStyles = TriStateStyles.Standard <System.ComponentModel.Category("Tri-State Tree View")> <System.ComponentModel.DisplayName("Style")> <System.ComponentModel.Description("Style of the Tri-State Tree View")> Public Property TriStateStyleProperty() As TriStateStyles Get Return TriStateStyle End Get Set TriStateStyle = Value End Set End Property ' <summary> ' Constructor. Create and populate an image list ' </summary> Public Sub New() MyBase.New() StateImageList = New System.Windows.Forms.ImageList() ' populate the image list, using images from the System.Windows.Forms.CheckBoxRenderer class For i As Integer = 0 To 2 ' Create a bitmap which holds the relevent check box style ' see http://msdn.microsoft.com/en-us/library/ms404307.aspx and http://msdn.microsoft.com/en-us/library/system.windows.forms.checkboxrenderer.aspx Dim bmp As New System.Drawing.Bitmap(16, 16) Dim chkGraphics As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(bmp) Select Case i ' 0,1 - offset the checkbox slightly so it positions in the correct place Case 0 System.Windows.Forms.CheckBoxRenderer.DrawCheckBox(chkGraphics, New System.Drawing.Point(0, 1), System.Windows.Forms.VisualStyles.CheckBoxState.UncheckedNormal) Exit Select Case 1 System.Windows.Forms.CheckBoxRenderer.DrawCheckBox(chkGraphics, New System.Drawing.Point(0, 1), System.Windows.Forms.VisualStyles.CheckBoxState.CheckedNormal) Exit Select Case 2 System.Windows.Forms.CheckBoxRenderer.DrawCheckBox(chkGraphics, New System.Drawing.Point(0, 1), System.Windows.Forms.VisualStyles.CheckBoxState.MixedNormal) Exit Select End Select StateImageList.Images.Add(bmp) Next End Sub ' <summary> ' Called once before window displayed. Disables default Checkbox functionality and ensures all nodes display an 'unchecked' image. ' </summary> Protected Overrides Sub OnCreateControl() MyBase.OnCreateControl() CheckBoxes = False ' Disable default CheckBox functionality if it's been enabled ' Give every node an initial 'unchecked' image IgnoreClickAction += 1 ' we're making changes to the tree, ignore any other change requests UpdateChildState(Me.Nodes, CInt(CheckedState.UnChecked), False, True) IgnoreClickAction -= 1 End Sub ' <summary> ' Called after a node is checked. Forces all children to inherit current state, and notifies parents they may need to become 'mixed' ' </summary> Protected Overrides Sub OnAfterCheck(e As System.Windows.Forms.TreeViewEventArgs) MyBase.OnAfterCheck(e) If IgnoreClickAction > 0 Then Return End If IgnoreClickAction += 1 ' we're making changes to the tree, ignore any other change requests ' the checked state has already been changed, we just need to update the state index ' node is either ticked or unticked. ignore mixed state, as the node is still only ticked or unticked regardless of state of children Dim tn As System.Windows.Forms.TreeNode = e.Node tn.StateImageIndex = If(tn.Checked, CInt(CheckedState.Checked), CInt(CheckedState.UnChecked)) ' force all children to inherit the same state as the current node UpdateChildState(e.Node.Nodes, e.Node.StateImageIndex, e.Node.Checked, False) ' populate state up the tree, possibly resulting in parents with mixed state UpdateParentState(e.Node.Parent) IgnoreClickAction -= 1 End Sub ' <summary> ' Called after a node is expanded. Ensures any new nodes display an 'unchecked' image ' </summary> Protected Overrides Sub OnAfterExpand(e As System.Windows.Forms.TreeViewEventArgs) ' If any child node is new, give it the same check state as the current node ' So if current node is ticked, child nodes will also be ticked MyBase.OnAfterExpand(e) IgnoreClickAction += 1 ' we're making changes to the tree, ignore any other change requests UpdateChildState(e.Node.Nodes, e.Node.StateImageIndex, e.Node.Checked, True) IgnoreClickAction -= 1 End Sub ' <summary> ' Helper function to replace child state with that of the parent ' </summary> Protected Sub UpdateChildState(Nodes As System.Windows.Forms.TreeNodeCollection, StateImageIndex As Integer, Checked As Boolean, ChangeUninitialisedNodesOnly As Boolean) For Each tnChild As System.Windows.Forms.TreeNode In Nodes If Not ChangeUninitialisedNodesOnly OrElse tnChild.StateImageIndex = -1 Then tnChild.StateImageIndex = StateImageIndex tnChild.Checked = Checked ' override 'checked' state of child with that of parent If tnChild.Nodes.Count > 0 Then UpdateChildState(tnChild.Nodes, StateImageIndex, Checked, ChangeUninitialisedNodesOnly) End If End If Next End Sub ' <summary> ' Helper function to notify parent it may need to use 'mixed' state ' </summary> Protected Sub UpdateParentState(tn As System.Windows.Forms.TreeNode) ' Node needs to check all of it's children to see if any of them are ticked or mixed If tn Is Nothing Then Return End If Dim OrigStateImageIndex As Integer = tn.StateImageIndex Dim UnCheckedNodes As Integer = 0, CheckedNodes As Integer = 0, MixedNodes As Integer = 0 ' The parent needs to know how many of it's children are Checked or Mixed For Each tnChild As System.Windows.Forms.TreeNode In tn.Nodes If tnChild.StateImageIndex = CInt(CheckedState.Checked) Then CheckedNodes += 1 ElseIf tnChild.StateImageIndex = CInt(CheckedState.Mixed) Then MixedNodes += 1 Exit For Else UnCheckedNodes += 1 End If Next If TriStateStyle = TriStateStyles.Installer Then ' In Installer mode, if all child nodes are checked then parent is checked ' If at least one child is unchecked, then parent is unchecked If MixedNodes = 0 Then If UnCheckedNodes = 0 Then ' all children are checked, so parent must be checked tn.Checked = True Else ' at least one child is unchecked, so parent must be unchecked tn.Checked = False End If End If End If ' Determine the parent's new Image State If MixedNodes > 0 Then ' at least one child is mixed, so parent must be mixed tn.StateImageIndex = CInt(CheckedState.Mixed) ElseIf CheckedNodes > 0 AndAlso UnCheckedNodes = 0 Then ' all children are checked If tn.Checked Then tn.StateImageIndex = CInt(CheckedState.Checked) Else tn.StateImageIndex = CInt(CheckedState.Mixed) End If ElseIf CheckedNodes > 0 Then ' some children are checked, the rest are unchecked tn.StateImageIndex = CInt(CheckedState.Mixed) Else ' all children are unchecked If tn.Checked Then tn.StateImageIndex = CInt(CheckedState.Mixed) Else tn.StateImageIndex = CInt(CheckedState.UnChecked) End If End If If OrigStateImageIndex <> tn.StateImageIndex AndAlso tn.Parent IsNot Nothing Then ' Parent's state has changed, notify the parent's parent UpdateParentState(tn.Parent) End If End Sub ' <summary> ' Called on keypress. Used to change node state when Space key is pressed ' Invokes OnAfterCheck to do the real work ' </summary> Protected Overrides Sub OnKeyDown(e As System.Windows.Forms.KeyEventArgs) MyBase.OnKeyDown(e) ' is the keypress a space? If not, discard it If e.KeyCode = System.Windows.Forms.Keys.Space Then ' toggle the node's checked status. This will then fire OnAfterCheck SelectedNode.Checked = Not SelectedNode.Checked End If End Sub ' <summary> ' Called when node is clicked by the mouse. Does nothing unless the image was clicked ' Invokes OnAfterCheck to do the real work ' </summary> Protected Overrides Sub OnNodeMouseClick(e As System.Windows.Forms.TreeNodeMouseClickEventArgs) MyBase.OnNodeMouseClick(e) ' is the click on the checkbox? If not, discard it Dim info As System.Windows.Forms.TreeViewHitTestInfo = HitTest(e.X, e.Y) If info Is Nothing OrElse info.Location <> System.Windows.Forms.TreeViewHitTestLocations.StateImage Then Return End If ' toggle the node's checked status. This will then fire OnAfterCheck Dim tn As System.Windows.Forms.TreeNode = e.Node tn.Checked = Not tn.Checked End Sub End ClassKonverter gibt's im Netz reichlich...
