foreach Loop with TreeViewItems

Question

I have some code I am asked to convert from Windows Forms over to WPF project. One thing I have run into is with TreeNodes being different.

This is the orginal windows forms code.

private void CreateTagTree()
{
    StringBuilder sb = new StringBuilder();

    // get list of plc program tags
    ABLink.Program plcProgram = myPLC.ProgramList[0];

    string[] plcInfo = (string[])cpuInfo.Value;
    sb.Append(plcInfo[0]+Environment.NewLine).Append(plcInfo[1] + Environment.NewLine).Append("Mode: " + plcInfo[2] + Environment.NewLine).Append("Status: " + plcInfo[3]);

    rootNode.Nodes.Clear();
    rootNode.Text = plcProgram.Name;
    rootNode.ToolTipText = sb.ToString();

    // add root node
    treeView1.Nodes.Add(rootNode);

    // get list of plc tag items
    ReadOnlyCollection<TagTemplate> DataTableList = plcProgram.TagItems();

    // create a node for each tag Template
    foreach (TagTemplate tagTemplate in DataTableList)
    {
        TreeNode tagNode = new TreeNode(tagTemplate.Name);
        tagNode.Tag = tagTemplate;
        AddNode(rootNode, tagTemplate);
    }         

}

////////
// adds a tag node to tree
private void AddNode(TreeNode parent, ABLink.TagTemplate template)
{
    TreeNode node = new TreeNode(template.Name);
    parent.Nodes.Add(node);

    // attache template to node
    node.Tag = template;
    node.ToolTipText = template.TypeName;

    ReadOnlyCollection<TagTemplate> memberList = template.Members;

    // if template has members
    foreach (ABLink.TagTemplate member in memberList)
        AddNode(node, member);
}

The above example works great and no issues with it. But trying to upgrade this program for more room to scale it in the future.

This is what I have so far and it is not displaying the treeview correct. It is leaving a lot of blank items and I am not sure why.

private void CreateTagTree()
{
    if (PLC5Radio.IsChecked == true)
    {

    //treeview1.Items.Add(rootNode);
    StringBuilder sb = new StringBuilder();

    // get list of plc program tags
    ABLink.Program plcProgram = myPLC.ProgramList[0];

    string[] plcInfo = (string[])cpuInfoAB.Value;
    sb.Append(plcInfo[0] + Environment.NewLine).Append(plcInfo[1] + Environment.NewLine).Append("Mode: " + plcInfo[2] + Environment.NewLine).Append("Status: " + plcInfo[3]);

    rootNode.Items.Clear();
    rootNode.Header = plcProgram.Name;
    rootNode.ToolTip = sb.ToString();

    // add root node
    //treeview1.Items.Add(rootNode);

    TreeViewItem prgNode = new TreeViewItem
    {
        Header = plcProgram.Name
    };

    //// get list of plc tag items
    ReadOnlyCollection<ABLink.TagTemplate> DataTableList = plcProgram.TagItems();

    // get collection of TagItems in 
    // filters "*" returns all tag names & atomic types
    tagListAB = plcProgram.TagItems(filtrName.Text, filterType.Text);

    // create a node for each tagTemplate
    foreach (ABLink.TagTemplate tagTemplate in tagListAB)
    {
        TreeViewItem tagNode = new TreeViewItem();
        tagNode.Items.Add(tagTemplate.Name);
        rootNode.Tag = tagTemplate;
        AddNodeAB(rootNode, tagTemplate);
    }
}

private void AddNodeAB(TreeViewItem parent, ABLink.TagTemplate template)
{
    TreeViewItem node = new TreeViewItem();
    node.Items.Add(template.Name);
    parent.Items.Add(node);

    // attache template to node
    node.Tag = template;
    node.ToolTip = template.TypeName;

    ReadOnlyCollection<ABLink.TagTemplate> memberList = template.Members;

    // if template has members
    foreach (ABLink.TagTemplate member in memberList)
        AddNodeAB(node, member);
}

Here is an image of what I am getting currently. Working program is on the right; my non working program is on the left with the extra spaces added in.

I believe part of the issue has to do with this

TreeNode tagNode = new TreeNode(tagTemplate.Name);

But with the changes in WPF I am not sure the best way to correct it. Any advice on what to be doing would be helpful.

Answer 1

in WinForms

TreeNode tagNode = new TreeNode(tagTemplate.Name);

creates a TreeNode and sets Text value.

WPF code

TreeViewItem tagNode = new TreeViewItem();
tagNode.Items.Add(tagTemplate.Name);

creates an empty TreeViewItem and adds a child. That is NOT an equivalent operation, obviously.

replacement for Text will be Header property:

TreeViewItem tagNode = new TreeViewItem();
tagNode.Header = tagTemplate.Name;
tagNode.Tag = tagTemplate;

and similarly in the next method

TreeViewItem node = new TreeViewItem();
node.Header = template.Name;
parent.Items.Add(node);

Header has object type and can contain any value, not just plain text, for example, another control. Please study this CodeProject article to get the overview: Basic Understanding of Tree View in WPF .