CODEWITHSUNDEEP
c#.netwinformstreeviewtreenode
user595581
user595581

Reputation: 11

What could be preventing the NodeMouseClick event from firing?

I'm working with a windows form app which I have treeview to show the list of folders , and I have attached NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e) event. and on click of node I call server method to populate the treeview. Here I could see that NodeMouseClick for one of my tree node is not at all getting triggered. however for rest of the nodes its working fine with no issues. can anyone tell me what is the exact reason that its not getting triggered. and I dont want to use After_Select event.

public Form1()
    {
        InitializeComponent();
        Init();
    }

    private void Init()
    {
        treeView1.Nodes.Add("root");

        for (int i = 0; i < 23; i++)
        {
            treeView1.Nodes[0].Nodes.Add(i.ToString());
            treeView1.Nodes[0].Nodes[i].Nodes.Add("child" + i.ToString());
        }

        treeView1.Nodes[0].Expand();
    }

use treeview of size = 280,369

Upvotes: 0

Views: 2610

Answers (2)

Cody Gray
Cody Gray

Reputation: 244772

As I mentioned before in the comments, the workaround is to drop down to the level of the Windows API, intercept mouse messages, and raise the node click event yourself. The code is ugly, but functional.

Add the following code to a new class in your project (I called it CustomTreeView):

class CustomTreeView : System.Windows.Forms.TreeView
{
    public event EventHandler<TreeNodeMouseClickEventArgs> CustomNodeClick;

    private const int WM_LBUTTONDOWN = 0x201;

    protected override void WndProc(ref System.Windows.Forms.Message m)
    {
        if (m.Msg == WM_LBUTTONDOWN)  // left mouse button down
        {
            // get the current position of the mouse pointer
            Point mousePos = Control.MousePosition;

            // get the node the user clicked on
            TreeNode testNode = GetNodeAt(PointToClient(mousePos));

            // see if the clicked area contained an actual node
            if (testNode != null)
            {
                // A node was clicked, so raise our custom event
                var e = new TreeNodeMouseClickEventArgs(testNode,
                                 MouseButtons.Left, 1, mousePos.X, mousePos.Y);
                if (CustomNodeClick != null)
                    CustomNodeClick(this, e);
            }
        }

        // call through to let the base class process the message
        base.WndProc(ref m);
    }
}

Then change all references to the System.Windows.Forms.TreeView control in your code to the new CustomTreeView class that you just created. This is a subclass of the existing TreeView control that you want to use instead. In case you're not familiar with subclassing, this is the way we modify the existing functionality, or bolt on new functionality to, an existing control. In this case, we've subclassed the original TreeView control to add the CustomNodeClick event that we'll be raising ourselves whenever we detect that a node has been clicked by the user.

Finally, change the event handler method in your form class to listen for the CustomNodeClick event that we're raising, rather than the buggered NodeMouseClick event you were trying to use before.

Compile and run. Everything should work as expected.

Upvotes: 1

Rami Alshareef
Rami Alshareef

Reputation: 7150

try to use AfterSelect Event it must be triggered after any node selection .

Upvotes: 0

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