原文:

由Xaml可以看出核心就是一个FluidBehavior，效果，就不过多阐述了

最核心的就是用一个定时器对于Shape的StrokeDashOffset进行改变，其中抽象FlowRate以及WhetherFluid用于控制流动速率以及是否流动

using System;using System.Windows;using System.Windows.Interactivity;using System.Windows.Shapes;using System.Windows.Threading;namespace MvvmLight1{    /// 
    /// 流动行为    /// 
    public class FluidBehavior : Behavior
     
          {        #region 依赖属性        /// 
      
        /// 流动速度        /// 
        public int FlowRate        {            get { return (int)GetValue(FlowRateProperty); }            set { SetValue(FlowRateProperty, value); }        }        // Using a DependencyProperty as the backing store for FlowRate.  This enables animation, styling, binding, etc...        public static readonly DependencyProperty FlowRateProperty =            DependencyProperty.Register("FlowRate", typeof(int), typeof(FluidBehavior), new PropertyMetadata(1));        /// 
      
        /// 是否流动        /// 
        public bool WhetherFluid        {            get { return (bool)GetValue(WhetherFluidProperty); }            set { SetValue(WhetherFluidProperty, value); }        }        // Using a DependencyProperty as the backing store for WhetherFluid.  This enables animation, styling, binding, etc...        public static readonly DependencyProperty WhetherFluidProperty =            DependencyProperty.Register("WhetherFluid", typeof(bool), typeof(FluidBehavior), new PropertyMetadata(true, OnWhetherFluidChanged));        private static void OnWhetherFluidChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)        {            var behavior = d as FluidBehavior;            if (Convert.ToBoolean(e.NewValue))            {                behavior._timer.Start();            }            else            {                behavior._timer.Stop();            }        }        #endregion        protected override void OnAttached()        {            base.OnAttached();            Fluid();        }        private readonly DispatcherTimer _timer = new DispatcherTimer();        //流动        private void Fluid()        {            _timer.Tick += (sender, e) =>            {                AssociatedObject.StrokeDashOffset -= FlowRate;            };            _timer.Interval = TimeSpan.FromSeconds(1d / 60);            if (WhetherFluid)            {                _timer.Start();            }        }    }}