Tree view control in winform vb.net

Hi every one,

I am working winform project

There is requirment intially i need to load all parent node and if user click on that + symobl according that i need to load data from other table on basic clicked parent id

But if load all parent intially so there would wont get + symobl

so how can i do that i am little bit confused

please assit me

this can also work

TreeNode parentNode1 = treeView1.Nodes.Add("Parent 1");
parentNode1.Nodes.Add("Loading child nodes...");
TreeNode parentNode2 = treeView1.Nodes.Add("Parent 2");
parentNode2.Nodes.Add("Loading child nodes...");

And then before expanding

private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e)
{
if(e.Node.Nodes.Count>0)
{
if(e.Node.FirstNode.Text== "Loading child nodes...")
{
//remove this child node with text "Loading child nodes..."
e.Node.FirstNode.Remove();
//add new node with condition
if(e.Node.Text== "Parent 1")
{
e.Node.Nodes.Add("Child of Parent1");
}
else if(e.Node.Text == "Parent 2")
{
e.Node.Nodes.Add("Child of Parent2");
}
}
}
}

1 Reply

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Kailash Polai9y ago
this can also work
TreeNode parentNode1 = treeView1.Nodes.Add("Parent 1");
parentNode1.Nodes.Add("Loading child nodes...");

TreeNode parentNode2 = treeView1.Nodes.Add("Parent 2");
parentNode2.Nodes.Add("Loading child nodes...");

And then before expanding

private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e)
        {
            if(e.Node.Nodes.Count>0)
            {
                if(e.Node.FirstNode.Text== "Loading child nodes...")
                {
                    //remove this child node with text "Loading child nodes..."
                    e.Node.FirstNode.Remove();

                    //add new node with condition
                    if(e.Node.Text== "Parent 1")
                    {
                        e.Node.Nodes.Add("Child of Parent1");
                    }
                    else if(e.Node.Text == "Parent 2")
                    {
                        e.Node.Nodes.Add("Child of Parent2");
                    }
                }
            }
        }