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EmptyListToVisibilityConverter

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天涯浪人
天涯浪人 2021-01-19 03:21

I\'m trying to do an \"empty list to visibility converter\" for WPF. This is an IValueConverter that takes an object ( that should be a list ) and if the list is empty (or i

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  • 情书的邮戳
    情书的邮戳 (楼主)
    2021-01-19 03:50

    You can't cast your list to IList , but you can cast it to ICollection, and then use ICollection.Count : see http://devw.wordpress.com/2011/07/18/empty-list-visibility-converter/

    public class EmptyListVisibilityConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value == null)
            return Visibility.Collapsed;
        else
        {
            ICollection list = value as ICollection;
            if (list != null)
            {
                if (list.Count == 0)
                    return Visibility.Collapsed;
                else
                    return Visibility.Visible;
            }
            else
                return Visibility.Visible;
        }
    }
    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)

    {
        throw new NotImplementedException();
    }
}

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