WPF 自定义控件完成库容表盘显示效果

先看一下显示效果：

       需要注意的地方有以下几点：

1. 表盘的刻度分部，长刻度和短刻度显示。
2. 在数值80W时，需要更改刻度盘的颜色渐变。
3. 在数值80W时，更改库容总数背景的显示，也是颜色渐变。刻度盘控件属性定义：

刻度盘的定义：

using Microsoft.Expression.Shapes;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;

namespace Dashboard_Demo
{
    /// 

    /// 刻度盘控件
    /// 
    /// add by zhidanfeng 2017.2.19
    [TemplatePart(Name = "PART_IncreaseCircle", Type = typeof(Arc))]
    public class Dashboard : Control
    {
        private Arc PART_IncreaseCircle;
        /// 

        /// 保存角度变化前的角度值(用于动画)
        /// 
        private double OldAngle;

        #region Constructors
        static Dashboard()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(Dashboard), new FrameworkPropertyMetadata(typeof(Dashboard)));
        }
        #endregion

        #region 依赖属性

        #region Angle 刻度盘起始角度
        /// 

        /// 刻度盘起始角度依赖属性
        /// 
        public static readonly DependencyProperty StartAngleProperty =
            DependencyProperty.Register(
                "StartAngle",
                typeof(double),
                typeof(Dashboard),
                new PropertyMetadata(0d));

        /// 

        /// 刻度盘起始角度
        /// 
        public double StartAngle
        {
            get { return (double)GetValue(StartAngleProperty); }
            set { SetValue(StartAngleProperty, value); }
        }
        #endregion

        #region Angle 刻度盘结束角度依赖属性
        /// 

        /// 刻度盘结束角度依赖属性
        /// 
        public static readonly DependencyProperty EndAngleProperty =
            DependencyProperty.Register(
                "EndAngle",
                typeof(double),
                typeof(Dashboard),
                new PropertyMetadata(0d));

        /// 

        /// 刻度盘结束角度依赖属性
        /// 
        public double EndAngle
        {
            get { return (double)GetValue(EndAngleProperty); }
            set
            {
                SetValue(EndAngleProperty, value);
            }
        }
        #endregion

        #region Minimum 最小值
        /// 

        /// 最小值依赖属性,用于Binding
        /// 
        public static readonly DependencyProperty MinimumProperty =
            DependencyProperty.Register(
                "Minimum",
                typeof(double),
                typeof(Dashboard),
                new PropertyMetadata(0.0));

        /// 

        /// 获取或设置最小值.
        /// 
        /// 最小值.
        public double Minimum
        {
            get { return (double)GetValue(MinimumProperty); }
            set { SetValue(MinimumProperty, value); }
        }
        #endregion

        #region Maximum 最大值
        /// 

        /// 最大值依赖属性,用于Binding
        /// 
        public static readonly DependencyProperty MaximumProperty =
            DependencyProperty.Register(
                "Maximum",
                typeof(double),
                typeof(Dashboard),
                new PropertyMetadata(100.0));

        /// 

        /// 获取或设置最大值.
        /// 
        /// 最大值.
        public double Maximum
        {
            get { return (double)GetValue(MaximumProperty); }
            set { SetValue(MaximumProperty, value); }
        }
        #endregion

        #region Value 当前值
        /// 

        /// 最大值依赖属性,用于Binding
        /// 
        public static readonly DependencyProperty ValueProperty =
            DependencyProperty.Register(
                "Value",
                typeof(double),
                typeof(Dashboard),
                new PropertyMetadata(0.0, new PropertyChangedCallback(OnValuePropertyChanged)));

        /// 

        /// 获取或设置当前值
        /// 
        public double Value
        {
            get
            {
                if (PART_IncreaseCircle == null)
                    return (double)GetValue(ValueProperty);

                if ((double)GetValue(ValueProperty) > 800000d)
                {
                    LinearGradientBrush brush = new LinearGradientBrush();
                    brush.StartPoint = new Point(0, 0);
                    brush.EndPoint = new Point(1, 0);
                    brush.GradientStops.Add(new GradientStop((Color)ColorConverter.ConvertFromString("#f0b046"), 0));
                    brush.GradientStops.Add(new GradientStop((Color)ColorConverter.ConvertFromString("#e83a2d"), 1));
                    PART_IncreaseCircle.Stroke = brush;
                }
                else
                {
                    LinearGradientBrush brush = new LinearGradientBrush();
                    brush.StartPoint = new Point(0, 0);
                    brush.EndPoint = new Point(1, 0);
                    brush.GradientStops.Add(new GradientStop((Color)ColorConverter.ConvertFromString("#1ccabd"), 0));
                    brush.GradientStops.Add(new GradientStop((Color)ColorConverter.ConvertFromString("#458ffc"), 1));
                    PART_IncreaseCircle.Stroke = brush;
                }
                return (double)GetValue(ValueProperty);

            }
            set { SetValue(ValueProperty, value); }
        }

        private static void OnValuePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            Dashboard dashboard = d as Dashboard;
            dashboard.OldAngle = dashboard.Angle;
            dashboard.SetAngle();
            dashboard.TransformAngle();
        }
        #endregion

        #region LongTickCount 长刻度个数
        public static readonly DependencyProperty LongTickCountProperty =
            DependencyProperty.Register(
                "LongTickCount",
                typeof(int),
                typeof(Dashboard),
                new PropertyMetadata(5));

        /// 

        /// 获取或设置长刻度个数，用于设置刻度盘显示几个长刻度
        /// 
        public int LongTickCount
        {
            get { return (int)GetValue(LongTickCountProperty); }
            set { SetValue(LongTickCountProperty, value); }
        }
        #endregion

        #region ShortTickCount 短刻度个数
        public static readonly DependencyProperty ShortTickCountProperty =
            DependencyProperty.Register(
                "ShortTickCount",
                typeof(int),
                typeof(Dashboard),
                new PropertyMetadata(3));

        /// 

        /// 获取或设置两个长刻度之间的短刻度的个数
        /// 
        public int ShortTickCount
        {
            get { return (int)GetValue(ShortTickCountProperty); }
            set { SetValue(ShortTickCountProperty, value); }
        }
        #endregion

        #region TickDurtion 刻度改变时的动画显示时长
        public static readonly DependencyProperty TickDurtionProperty = DependencyProperty.Register("TickDurtion"
            , typeof(Duration)
            , typeof(Dashboard),
            new PropertyMetadata(new Duration(TimeSpan.FromMilliseconds(400))));

        /// 

        /// 刻度改变时的动画显示时长
        /// 
        public Duration TickDurtion
        {
            get { return (Duration)GetValue(TickDurtionProperty); }
            set { SetValue(TickDurtionProperty, value); }
        }
        #endregion

        #region ShortTicksBrush 短刻度颜色
        public static readonly DependencyProperty ShortTicksBrushProperty = DependencyProperty.Register("ShortTicksBrush"
            , typeof(Brush)
            , typeof(Dashboard));

        /// 

        /// 短刻度颜色
        /// 
        public Brush ShortTicksBrush
        {
            get { return (Brush)GetValue(ShortTicksBrushProperty); }
            set { SetValue(ShortTicksBrushProperty, value); }
        }
        #endregion

        #region LongTicksBrush 长刻度颜色
        public static readonly DependencyProperty LongTicksBrushProperty = DependencyProperty.Register("LongTicksBrush"
            , typeof(Brush)
            , typeof(Dashboard));

        /// 

        /// 长刻度颜色
        /// 
        public Brush LongTicksBrush
        {
            get { return (Brush)GetValue(LongTicksBrushProperty); }
            set { SetValue(LongTicksBrushProperty, value); }
        }
        #endregion

        #region Content
        public object Content
        {
            get { return (object)GetValue(ContentProperty); }
            set { SetValue(ContentProperty, value); }
        }

        public static readonly DependencyProperty ContentProperty =
            DependencyProperty.Register("Content", typeof(object), typeof(Dashboard));
        #endregion

        #region ContentTemplate
        public DataTemplate ContentTemplate
        {
            get { return (DataTemplate)GetValue(ContentTemplateProperty); }
            set { SetValue(ContentTemplateProperty, value); }
        }

        public static readonly DependencyProperty ContentTemplateProperty =
            DependencyProperty.Register("ContentTemplate", typeof(DataTemplate), typeof(Dashboard));
        #endregion

        #endregion

        #region Private依赖属性

        #region Angle 刻度盘当前值所对应的角度
        /// 

        /// 刻度盘当前值所对应的角度依赖属性
        /// 
        public static readonly DependencyProperty AngleProperty =
            DependencyProperty.Register(
                "Angle",
                typeof(double),
                typeof(Dashboard),
                new PropertyMetadata(0d));

        /// 

        /// 刻度盘当前值所对应的角度
        /// 
        public double Angle
        {
            get { return (double)GetValue(AngleProperty); }
            private set { SetValue(AngleProperty, value); }
        }
        #endregion

        #region ShortTicks 短刻度线集合
        /// 

        /// 短刻度线依赖属性,用于Binding
        /// 
        public static readonly DependencyProperty ShortTicksProperty =
            DependencyProperty.Register(
                "ShortTicks",
                typeof(IList