如何在全屏页面中显示ComboBox的所有项目？

Question

I am creating ComboBox for windows phone 8.1 on a Universal Apps project, but I would like show always all items on fullscreen page. On windows phone 8 I do

ListPicker.ExpansionMode = ExpansionMode.FullScreenOnly;

but, in ComboBox for windows phone 8.1 I don't found option.

How can I solve this problem?

Thanks!

Answer 1

The ComboBox Control in WP8.1 will decide to show items in FullScreen or DropDown List. When your items count > 5 , it will show in FullScreen. OtherWise, it will show in DropDown List. We can't change it by code.

Answer 2

Late answer but hope it helps others.

By default the combobox will show longlist only if the count of items has exceeded 5 items. If you need to show the fullscreen for combobox you can attach a listpicker flyout to a button in place of combobox. That would be the ideal solution I guess. And it almost satisfies all the implementations of longlist

Answer 3

If (you have 3 items in combobox) then { Also add 3 items in combobox whith content " " }

Add this handler:

private void DoSelectionChanged(object sender, SelectionChangedEventArgs e)
{
    ComboBox cb = (sender as ComboBox);
    if (cb.SelectedIndex > -1)
    {
        string s = (cb.SelectedValue as ComboBoxItem).Content as string; 
        if (s == " ")
        {
            cb.SelectedIndex = cb.GetLastIndex();
        }
    }
    cb.SetLastIndex(cb.SelectedIndex);
}

public static class Extensions
{
    private static Dictionary<ComboBox, int> _lastIndex = new Dictionary<ComboBox, int>();
    public static int GetLastIndex(this ComboBox me)
    {
        return _lastIndex.ContainsKey(me) ? _lastIndex[me] : -1;
    }
    public static void SetLastIndex(this ComboBox me, int NewValue)
    {
        if (_lastIndex.ContainsKey(me))
            _lastIndex[me] = NewValue;
        else
            _lastIndex.Add(me,NewValue);
    }
}