BoolToVisibilityConverter In WPF

BoolToVisibilityConverter这个转换器用于判断 bool 转 Collapsed(不占空间) 还是Hidden(占空间)。

[ValueConversion(typeof(bool), typeof(Visibility))]
    public class BoolToVisibilityConverter : IValueConverter
    {
        public BoolToVisibilityConverter()
            : this(true)
        {

        }
        public BoolToVisibilityConverter(bool collapsewhenInvisible)
            : base()
        {
            CollapseWhenInvisible = collapsewhenInvisible;
        }
        public bool CollapseWhenInvisible { get; set; }

        public Visibility FalseVisible
        {
            get
            {
                if (CollapseWhenInvisible)
                {
                    return Visibility.Collapsed;
                }
                else
                {
                    return Visibility.Hidden;
                }
            }

        }
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null)
                return Visibility.Visible;
            return (bool)value ? Visibility.Visible : FalseVisible;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null)
                return true;
            return ((Visibility)value == Visibility.Visible);
        }
    }

使用：

  <converter:BoolToVisibilityConverter CollapseWhenInvisible="False" x:Key="_BoolToVisibilityConverter"/>

CollapseWhenInvisible="False" 为占空间，

CollapseWhenInvisible="True" 为不占空间，

默认 CollapseWhenInvisible="True" 。