WPF 自定义控件之禁用时的鼠标样式

废话不多说，客官先看图

 在WPF 中，控件禁用的时候，虽然可以利用触发器去修改控件的本身的样式，但是，鼠标样式Cursor确不会生效。可是产品和UI怎么会放过你呢，毕竟web控件可是可以改的。

解决方案：

利用装饰器和附加属性，完美继承原先的样式和逻辑，而且对所有控件都有效；

装饰器代码：

思路很简单，就是给控件添加一个蒙层，禁用的时候，鼠标其实是位于在蒙层上；

public class UnableAdorner : Adorner
    {
        private readonly VisualCollection _collection;

        private readonly Grid _grid;
        private Border _border;

        protected override int VisualChildrenCount => _collection.Count;

        protected override Visual GetVisualChild(int index) => _collection[index];

        public UnableAdorner(UIElement uIElement) : base(uIElement) {

            _collection = new VisualCollection(this);
            _grid = new Grid();
            _border = new Border()
            {
                Background = Brushes.Transparent,
                Cursor = (Cursor)TryFindResource("UnableCursor") ?? Cursors.No,
            };

            _grid.Children.Add(_border);
            _collection.Add(_grid);
        }

        public void SetEnable(bool isEnable) {
            _border.IsHitTestVisible = !isEnable;
        }

        protected override Size MeasureOverride(Size constraint)
        {
            return base.MeasureOverride(constraint);
        }

        protected override Size ArrangeOverride(Size finalSize)
        {
            _grid.Arrange(new Rect(finalSize));
            return base.ArrangeOverride(finalSize);

        }
    }

附加属性：

利用附加属性，给控件添加对应的装饰器

    public class Assists
    {
        #region 控件IsEnable 属性,用于重写IsEnable样式
        public static bool GetIsEnable(DependencyObject obj)
        {
            return (bool)obj.GetValue(IsEnableProperty);
        }

        public static void SetIsEnable(DependencyObject obj, bool value)
        {
            obj.SetValue(IsEnableProperty, value);
        }

        // Using a DependencyProperty as the backing store for IsEnable.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty IsEnableProperty =
            DependencyProperty.RegisterAttached("IsEnable", typeof(bool), typeof(Assists), new PropertyMetadata(true, IsEnablePropertyChanged));

        private static void IsEnablePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is UIElement uIElement) {
                var adorner = (UnableAdorner)uIElement.GetOrAddAdorner(typeof(UnableAdorner));
                adorner.SetEnable((bool)e.NewValue);
            }
        }
        #endregion


    }

注意：装饰器使用的时候 需要AdornerDecorator；

源码地址：https://github.com/Super0Lan/ControlDesign