Question

I am attempting to populate a Tree View in C#. I can successfully fill the first tier however I am having trouble adding the children. The last two lines of Code are what I have currently tried. However the same error is given at runtime: “Object Reference no set to an Object instance”

for (int index = 0; index < jobArray.Length; index++)
        {
            TreeNode newNode = new TreeNode();
            newNode.Text = jobArray[index].name;
            newNode.Tag = jobArray[index];
            treeView1.Nodes.Add(newNode);
            foreach(Truss t in jobArray[index].trusses)
            {
                TreeNode newNode1 = new TreeNode();
                newNode1.Text = t.name;
                newNode1.Tag =  t;
                treeView1.Nodes[0].FirstNode.Nodes.Add(newNode1);
               // treeView1.SelectedNode.Nodes.Add(newNode1);
            }
        }

Any suggestions would be great!

Answer 1

Replace treeView1.Nodes[0].FirstNode.Nodes.Add(newNode1); with:

newNode.Nodes.Add(newNode1);