Question

I’m populating a TreeView with nodes based on an XML document. However, it seems that when I go to put an attribute’s value into a textbox, it loses it’s newlines/carriage returns/tabs.

I start by adding a bunch of nodes with “task names”. Each task has one or more queries in the XML document. Like so: <Tasks><Task name="aTaskName"><Queries><add Query="a long string with tabs and newlines and such" /></Queries></Task> ... </Tasks>

void PopulateQueries(XDocument doc, TreeView tree)
{
    foreach (TreeNode node in tree.Nodes)
    {
        var taskName = node.Text;
        var queriesNode = node.Nodes.Add("Queries");
        var queries = doc.Descendants("Tasks")
            .Descendants("Task")
            .Where(d => d.Attribute("name").Value == taskName)
            .Descendants("Queries")
            .Descendants("add")
            .ToList();

        for (int i = 0; i < queries.Count;i++)
        {
            queriesNode.Nodes.Add(queries[i].Attribute("Query").Value, "query" + i);
        }
    }
}

Later in a node click event:

void treeView1_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
{
    textBoxRaw.Text = string.Empty;
    if (e.Node.Text.StartsWith("query"))
    {
        textBoxRaw.Text = e.Node.Name;
    }
}

The Query attribute value contains a long SQL query with newlines, tabs, etc. But none of that seems to show up in the (multiline) text box, despite all my shouting at Visual Studio. What am I doing wrong? Also, var doc = XDocument.Load(filename, LoadOptions.PreserveWhitespace); doesn’t seem to work either.

Answer 1

XML processors must normalize attribute values by converting their whitespace characters (CR, LF, HT, etc) to a single space.

If you want to have values with such characters, you should consider having them as text nodes instead of attribute values.