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

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;
}