Well Int32.TryParse
should not raise an exception...
//Gets the number contained in a Node's header
public static int getNumber(string parentNodeHeader)
{
int curNumber;
//if parse to Int32 fails, curNumber will still be 0
Int32.TryParse(parentNodeHeader, out curNumber);
return curNumber;
}
EDIT :
Seems that you should do something like that (somme null check would be better, of course)
//Initializing a parent TreeView Item
var parentItem = (TreeViewItem)SelectedItem.Parent;
var header = (TextBlock)parentItem.Header;
int curNumber = getNumber(header.Text);