So deaktivieren Sie die Textauswahl in einem Treeview (WinForms .net) ⇐ C#

[Anonymous]

Ich erstelle eine benutzerdefinierte TreeView -Steuerung für meine WinForm -Anwendung. Dabei bemerkte ich, dass es eine wirklich ärgerliche Funktion der Treeview gibt, die ich Schwierigkeiten habe, zu entfernen. Ich nehme jedoch auch keine Zeichnung jeglicher Art an. Ich suche nach einer Möglichkeit, dies zu tun, ohne den Stil auf den Eigentümer festzulegen und den Text der hinzugefügten Knoten manuell zu zeichnen. < /P>

Code: Select all

public class CustomTreeView : TreeView
{
// Fields for the custom checkbox images
private Image _checkedImage = Properties.Resources.CheckIcon;
private Image _uncheckedImage = Properties.Resources.UnCheckIcon;
private Image _intermediateImage = Properties.Resources.IntermediateCheckIcon;
private ImageList _imageList;

public CustomTreeView()
{
this.CheckBoxes = false;

_imageList = new ImageList();
_imageList.ImageSize = new Size(26, 26);
_imageList.Images.Add("Unchecked", _uncheckedImage);
_imageList.Images.Add("Checked", _checkedImage);
_imageList.Images.Add("Intermediate", _intermediateImage);
this.ImageList = _imageList;

this.Font = new Font("Gadugi", 12f);
this.ForeColor = Color.DodgerBlue;
this.BackColor = SystemColors.Control;
this.BorderStyle = BorderStyle.None;
this.Scrollable = true;

this.ShowLines = false;

this.ShowRootLines = false;
this.ShowNodeToolTips = true;

this.ShowPlusMinus = false;

this.HideSelection = false;
this.ItemHeight = 30;
}

private int GetEffectiveState(TreeNode node)
{
if (node.Nodes.Count == 0)
{
return node.Checked ? 1 : 0;
}
else
{
bool allChecked = true;
bool anyChecked = false;
foreach (TreeNode child in node.Nodes)
{
int childState = GetEffectiveState(child);
if (childState == 0)
allChecked = false;
else if (childState == 1)
anyChecked = true;
else
{
allChecked = false;
anyChecked = true;
}
}
if (allChecked)
return 1;
else if (anyChecked)
return 2;
else
return 0;
}
}

private void UpdateStateImageIndex(TreeNode node)
{
node.ImageIndex = GetEffectiveState(node);
node.SelectedImageIndex = node.ImageIndex;
}

private void SetNodeChecked(TreeNode node, bool checkedState)
{
node.Checked = checkedState;
foreach (TreeNode child in node.Nodes)
{
SetNodeChecked(child, checkedState);
}
}

private void UpdateStateIndices(TreeNode node)
{
while (node != null)
{
UpdateStateImageIndex(node);
node = node.Parent;
}
}

protected override void OnMouseDown(MouseEventArgs e)
{
TreeViewHitTestInfo hitTestInfo = HitTest(e.Location);
if (hitTestInfo.Location == TreeViewHitTestLocations.Image)
{
TreeNode node = hitTestInfo.Node;
if (node != null)
{
int currentState = GetEffectiveState(node);
if (currentState == 1)
{
SetNodeChecked(node, false);
}
else
{
SetNodeChecked(node, true);
}
UpdateStateIndices(node);
}
}
}

protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
TreeViewHitTestInfo hitTestInfo = HitTest(e.Location);
if (hitTestInfo.Location == TreeViewHitTestLocations.Image)
{
this.Cursor = Cursors.Hand;
}
else
{
this.Cursor = Cursors.Default;
}
}

protected override void OnAfterCheck(TreeViewEventArgs e)
{
base.OnAfterCheck(e);
UpdateStateIndices(e.Node);
}

private void UpdateStateIndicesRecursive(TreeNode node)
{
node.Expand();
foreach (TreeNode child in node.Nodes)
{
UpdateStateIndicesRecursive(child);
}
UpdateStateImageIndex(node);
}

public void UpdateAllStateIndices()
{
foreach (TreeNode node in this.Nodes)
{
UpdateStateIndicesRecursive(node);
}
}

protected override void OnBeforeCollapse(TreeViewCancelEventArgs e)
{
e.Cancel = true;
}

protected override void OnKeyDown(KeyEventArgs e)
{
if (e.KeyCode == Keys.Up || e.KeyCode == Keys.Down || e.KeyCode == Keys.Left || e.KeyCode == Keys.Right)
{
e.Handled = true;
}
base.OnKeyDown(e);
}

protected override void OnBeforeSelect(TreeViewCancelEventArgs e)
{
e.Cancel = true;
base.OnBeforeSelect(e);
}
}