BoolToObjectConverter

   介绍两种BoolToObjectConverter,一种是自定义的，一个是devexpress的

   xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"

     xmlns:com="http://schemas.Sample.com.cn/common"

    public class BoolToObjectConverter : DependencyObject, IValueConverter
    {
        public static readonly DependencyProperty TrueValueProperty = DependencyProperty.RegisterAttached(nameof(TrueValue), typeof(object), typeof(BoolToObjectConverter));
        public static readonly DependencyProperty FalseValueProperty = DependencyProperty.RegisterAttached(nameof(FalseValue), typeof(object), typeof(BoolToObjectConverter));
        public static readonly DependencyProperty NullValueProperty = DependencyProperty.RegisterAttached(nameof(NullValue), typeof(object), typeof(BoolToObjectConverter));
        public object NullValue
        {
            get { return GetValue(NullValueProperty); }
            set { SetValue(NullValueProperty, value); }
        }
        public object TrueValue
        {
            get { return GetValue(TrueValueProperty); }
            set { SetValue(TrueValueProperty, value); }
        }
        public object FalseValue
        {
            get { return GetValue(FalseValueProperty); }
            set { SetValue(FalseValueProperty, value); }
        }

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if(value == null || (!(value is bool?) && !(value is bool)))
            {
                return NullValue;
            }
            return ((bool)value) ? TrueValue : FalseValue;

        }
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
    }

    <UserControl.Resources>
               <com:BoolToObjectConverter x:Key="wrapIconSelector">
            <com:BoolToObjectConverter.TrueValue>
                <BitmapImage UriSource="pack://application:,,,/Sineva.Modeler.Define;component/image/word-wrap-on.png" />
            </com:BoolToObjectConverter.TrueValue>
            <com:BoolToObjectConverter.NullValue>
                <BitmapImage UriSource="pack://application:,,,/Sineva.Modeler.Define;component/image/word-wrap-off.png" />
            </com:BoolToObjectConverter.NullValue>
            <com:BoolToObjectConverter.FalseValue>
                <BitmapImage UriSource="pack://application:,,,/Sineva.Modeler.Define;component/image/word-wrap-off.png" />
            </com:BoolToObjectConverter.FalseValue>
        </com:BoolToObjectConverter>
        <com:BoolToObjectConverter x:Key="actionStateIconSelector">
            <com:BoolToObjectConverter.TrueValue>
                <BitmapImage UriSource="pack://application:,,,/Sineva.Modeler.Define;component/image/mini_ok.png" />
            </com:BoolToObjectConverter.TrueValue>
            <com:BoolToObjectConverter.NullValue>
                <BitmapImage UriSource="pack://application:,,,/Sineva.Modeler.Define;component/image/mini_error.png" />
            </com:BoolToObjectConverter.NullValue>
            <com:BoolToObjectConverter.FalseValue>
                <BitmapImage UriSource="pack://application:,,,/Sineva.Modeler.Define;component/image/mini_error.png" />
            </com:BoolToObjectConverter.FalseValue>
        </com:BoolToObjectConverter>
        <dx:BoolToObjectConverter x:Key="ActionStateIconSelector">
            <dx:BoolToObjectConverter.TrueValue>
                <Visibility>Visible</Visibility>
            </dx:BoolToObjectConverter.TrueValue>
            <dx:BoolToObjectConverter.FalseValue>
                <Visibility>Hidden</Visibility>
            </dx:BoolToObjectConverter.FalseValue>
        </dx:BoolToObjectConverter>
    </UserControl.Resources>

这两者的使用区别则是绑定的值有没有null的情况，有null的情况绑定devexpress类型的BoolToObjectConverter则会显示无效bool值转换。但没有null的情况下，两者是都可以绑定的。

例如某个控件的IsEnabled属性只有true和false则可以绑定devexpress类型的BoolToObjectConverter