How to get Values from Treeview and assign to GridView

Here is the basics;

private void readAndWrite()
{
//Read a value from Treeview
int theNode = 1;
String theValue = treeView1.Nodes[theNode].Text;

//set a value in a DataGridView
int theRow = 10;
int theCol = 5;
dataGridView1.Rows[theRow].Cells[theCol].Value = theValue;
}

That's a much better question.

To show the data in the TreeView you can either use the XDocument[^] (or any of the other XML Parsing classes in .Net) to load the XML file, parse the node structure out and then create and add nodes to the TV. Alternatively it looks like .Net 4 has a DataBindings[^] property on Controls that may do the job for you.

The docs show you how to create and add nodes manually. Then you can handle the AfterSelect event to change what's shown elsewhere on your app. I really don't use grids that much so I can't help you with that one. Sorry :(

One thing you could do is use a BindingList. (See here: BindingList<(Of <(T>)>) Class[^])

What you would do is create the binding list to be set up with either a custom class or a pre-defined class that would contain your information.

Then, you would bind the datagridview to that list. For an example with the datagridview, see here: C# Tutorial - Binding a DataGridView to a Collection[^])

Then, when the selected item in the TreeView is changed, clear the binding list and add a new item to it. The datagridview will update with the changes.