Question

I’ve added checkboxes to my treeview, and am using the AfterSelect event (also tried AfterChecked).

My tree view is like this

1 State
1.1 City1
1.2 City2
1.3 City3
2 State
2.1 City1
2.2 City2
2.3 City3

etc.

I’m trying to run an event, so when a checkbox is clicked, the tag is added to an array ready for processing later. I also need to use it so if a state is clicked, it selects all the cities under that leaf.

treeSections.AfterSelect += node_AfterCheck;

private void node_AfterCheck(object sender, TreeViewEventArgs e)
{
    MessageBox.Show("testing");
}

The above code works on the treeview if it has no heirarchy. But don’t work on the treeview with the states and cities unless the text/label for each leaf is double clicked.

Any ideas?

Answer 1

I suggest using the combination of TreeView.NodeMouseClick and TreeView.KeyUp events… the click event will provide you the clicked node via event args and with the keyup you can use the currently selected node. Follow the example below…

//This is basic - you may need to modify logically to fit your needs
void ManageTreeChecked(TreeNode node)
{
   foreach(TreeNode n in node.Nodes)
   {
      n.Checked = node.Checked;
   }
}

private void convTreeView_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
   ManageTreeChecked(e.Node);
}
private void convTreeView_KeyUp(object sender, KeyEventArgs e)
{
   if (e.KeyCode == Keys.Space)
   {
      ManageTreeChecked(convTreeView.SelectedNode);
   }
}

Using the node given each event you can now cycle through the Nodes collection on that node and modify it to be checked/unchecked given the status of the checked status of the node you acted upon.

You can even get fancy enough to uncheck a parent node when all child nodes are unchecked. If you desire a 3-state treenode (All Checked, Some Checked and None Checked) then you have to create it or find one that has been created.

Enjoy, best of luck.