GTK Sharp Refresh / Redraw widget - combobox

Question

I'm trying to develop a really simple GUI with mono and GTK sharp. I have a few two combobox and I need to change the options available in the secod based on the selected item from the first one:
//Create window container
var mainContainer = new Table (3, 1, false);
//add form
var formContainer = new Table (1, 3, true);
//FIRST COMBOBOX
pdfSelect = new ComboBox(new string[] {"Monthly", "Monthly Offline", "Quarterly" }) { Active = 2 };
pdfSelect.Changed += new EventHandler(OnPdfSelectChanged);
formContainer.Attach (pdfSelect, 1, 2, 0, 1);
//MONTH COMBOBOX
monthSelect = new ComboBox(new string[] { "January","February","March","April","May","June","July","August","September","October","November","December" }){ Active = 0 };
formContainer.Attach(monthSelect, 2, 3, 0, 1);
mainContainer.Attach(formContainer, 0, 1, 0, 1);
win.Add(mainContainer);
My change event is below:
public static void OnPdfSelectChanged(object o, EventArgs args) {
ComboBox combo = o as ComboBox;
if (o == null) return;
if (combo.ActiveText.Equals("Monthly") || combo.ActiveText.Equals("Monthly Offline"))
{
monthSelect = new ComboBox(new string[] { "January","February","March","April","May","June","July",
"August","September","October","November","December" }) { Active = 0 };
}
else
{
monthSelect = new ComboBox(new string[] { "January", "April", "July", "October" }) { Active = 0 };
}
//TODO REFRESH WINDOW
}
The code works but the second combobox seems to dont be updated. I guess I need to refresh the window?
Thanks

Answer 1

The problem is that you're assigning a new Gtk.ComboBox to the monthSelect variable but that doesn't automatically remove the old combobox from the window and add this new one. What you want is to clear the contents of the combobox and add the new content. Something like:
monthSelect.Clear();
monthSelect.AppendText("January");
monthSelect.AppendText("April");
monthSelect.AppendText("July");
monthSelect.AppendText("October");

Answer 2

I got it to work the two mean things is to call Clear() as fog said (+1) but after that you need to assign a cell rendertext or the new items will not be displayed:
Gtk.ComboBox.Clear Method "Unsets all the mappings on all renderers for this combo box."
public static void OnPdfSelectChanged(object o, EventArgs args) {
ComboBox combo = o as ComboBox;
if (o == null) return;
//Set entries
var entries = new string[] { "January","February","March","April","May","June","July", "August","September","October","November","December" };
if (combo.ActiveText.Equals("Quarterly"))
{
entries = new string[] { "January", "April", "July", "October" };
}
//clear previous data
monthSelect.Clear();
//cells data
ListStore store = new ListStore(typeof(string));
foreach (var item in entries) {
store.AppendValues(item);
}
//assign data to combobox
monthSelect.Model = store;
//renderer for cells
var cellRenderer = new CellRendererText();
monthSelect.PackStart(cellRenderer, true);
monthSelect.AddAttribute(cellRenderer, "text", 0);
//set first item as active
monthSelect.Active = 0;
}

Answer 3

Maybe too late, but...
((ListStore)combobox.Model).Clear();
combobox.AppendText("item");