NodeCheckedChanged with AutoCheckChildNodes

[Jean-Philippe Pagé]

I was wondering if there is a way to disable the NodeCheckedChanged event from being fired for all children nodes when AutoCheckChildNodes is set to true.

The reason why I want to know this is that I store an xml string inside the tag of each node.  Every node is a possible record in a database.  The xml being stored inside each node contains the information for the current node along with all its children nodes.  When the user checks or unchecks a node, I need to give this xml to another component which in turns inserts or removes the proper information to/from the database.  I know I could keep raising this event for every node and simply keep the info for the current node in the tag, but this could make for a lot of back and forth between components and the database while this way only one call is being made.

I was thinking of keeping a flag inside the NodeCheckedChanged event and checking this flag before processing like the following:

        private void radTreeView1_NodeCheckedChanged(object sender, RadTreeViewEventArgs e)
        {
            if (!m_processing)
            {
                m_processing = true;
                // do work....
                m_processing = false;
            }
        }

but I noticed that the calls weren't nested and that it was actually doing all the code before moving on to the next child/sibling node.

Is there a workaround or another event I could use for this?  I want to do the work only once and for the node that was actually checked/unchecked.

[Jean-Philippe Pagé]

I have found a workaround for this but I am not sure how reliable it is.  I have a member RadTreeNode that I keep and I set its value whenever I enter the NodeMouseDown event.  Then in the NodeCheckedChanged event before doing anything I make sure that the received node is the same node as in the NodeMouseDown event.

private void radTreeView1_NodeCheckedChanged(object sender, RadTreeViewEventArgs e)
        {
            if (e.Node == m_ClickedNode)
            {
                // Do work here...
            }
        }

        private void radTreeView1_NodeMouseDown(object sender, RadTreeViewMouseEventArgs e)
        {
            m_ClickedNode = e.Node;
        }

[Martin Vasilev]

Hello Jean-Philippe Pagé,

I have already answered in the support ticket concerning this topic. I just want to share my notes here as well:

I think that your work-around is very suitable for the described issue. I only suggest that you clear the m_ClickedNode parameter to avoid any undesired effects from NodeCheckedChanged event:

void radTreeView1_NodeMouseDown(object sender, RadTreeViewMouseEventArgs e)
{
    m_ClickedNode = e.Node;
}

private void radTreeView1_NodeCheckedChanged(object sender, RadTreeViewEventArgs e)
{
    if (e.Node == m_ClickedNode)
    {
        Debug.WriteLine("ChangedNode: " + e.Node.Text);
        m_ClickedNode = null;
    }
}

Do not hesitate to contact me again if you have any other questions.

Kind regards,
Martin Vasilev
the Telerik team

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[Jean-Philippe Pagé]

Thank you Martin, I will add your suggestion into my code.

[Jean-Philippe Pagé]

After doing some more testing we noticed that we had forgotten about a little something with this workaround.... some people are more keyboard punchers than mouse clickers.  This means that I also have to keep track of the m_ClickedNode (which has now been renamed to m_SelectedNode) in the SelectedNodeChanged method.  Good think multiselection is not allowed in my tree.

[Boyko Markov]

Hi Jean-Philippe Pagé,

You can also try the following as a solution:

1. Subscribe to the KeyDown event of RadTreeView
2.  Save the m_SelectedNode in the event handler if the "Space" key is pressed.

void radTreeView1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Space)
            {
                m_SelectedNode = this.radTreeView1.SelectedNode;
            }
        }

If you need more information, please do not hesitate to contact us.
I hope this helps.


Greetings,
Boyko Markov
the Telerik team

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Watch a video on how to optimize your support resource searches and check out more tips on the blogs.