<UserControl?x:Class="TopControl.Wheel"
?????????????xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
?????????????xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
?????????????xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"?
?????????????xmlns:d="http://schemas.microsoft.com/expression/blend/2008"?
?????????????xmlns:local="clr-namespace:TopControl"
?????????????mc:Ignorable="d"?
?????????????Width="30"?Height="180">
????<Grid>
????????<!--?進度?-->
????????<Grid?Width="2"?Background="#0a0a0a"?Height="180"?HorizontalAlignment="Left"?VerticalAlignment="Bottom"/>
????????<Grid?Width="2"?x:Name="Grid_Value"?Height="0"?HorizontalAlignment="Left"?VerticalAlignment="Bottom">
????????????<Grid?Height="180"?VerticalAlignment="Bottom">
????????????????<Grid.Background>
????????????????????<LinearGradientBrush?StartPoint="0,0"?EndPoint="0,1">
????????????????????????<GradientStop?Offset="0"?Color="#f0d967"/>
????????????????????????<GradientStop?Offset="1"?Color="#33b08d"/>
????????????????????</LinearGradientBrush>
????????????????</Grid.Background>
????????????</Grid>
????????</Grid>
????????<Grid?Background="#0a0a0a"?Width="26"?HorizontalAlignment="Right"?Height="180"?Margin="2,0,0,0"/>
????????<!--?滾輪?-->
????????<Grid?x:Name="WheelArea"?Height="176"?Width="22"?HorizontalAlignment="Right"?Margin="0,0,2,0"
??????????????MouseDown="WheelArea_MouseDown"?MouseMove="WheelArea_MouseMove"?MouseUp="WheelArea_MouseUp"?MouseWheel="WheelArea_MouseWheel">
????????????<Grid.Background>
????????????????<LinearGradientBrush?StartPoint="0,0"?EndPoint="0,1">
????????????????????<GradientStop?Color="#141414"?Offset="0"/>
????????????????????<GradientStop?Color="#3c3c3c"?Offset="0.5"/>
????????????????????<GradientStop?Color="#141414"?Offset="1"/>
????????????????</LinearGradientBrush>
????????????</Grid.Background>
????????????<Grid?x:Name="LayerBox"?IsHitTestVisible="False"/>
????????</Grid>
????</Grid>
</UserControl>

2）創(chuàng)建 Wheel.xaml.cs 代碼如下:

using?System.Windows;
using?System.Windows.Controls;
using?System.Windows.Input;

namespace?TopControl
{
????public?partial?class?Wheel?:?UserControl
????{
????????public?Wheel()
????????{
????????????InitializeComponent();
????????????Loaded?+=?Wheel_Loaded;
????????}

????????#region?屬性

????????public?int?MinValue?{?get;?set;?}?=?-720;

????????public?int?MaxValue?{?get;?set;?}?=?720;

????????public?int?Value?{?get;?set;?}?=?-720;

????????#endregion

????????#region?控件事件

????????private?void?Wheel_Loaded(object?sender,?RoutedEventArgs?e)
????????{
????????????InitLayer();
????????}

????????private?void?WheelArea_MouseDown(object?sender,?MouseButtonEventArgs?e)
????????{
????????????if?(e.ChangedButton?==?MouseButton.Left)
????????????{
????????????????BeginDrag();
????????????}
????????}

????????private?void?WheelArea_MouseMove(object?sender,?MouseEventArgs?e)
????????{
????????????if?(_dragMode)
????????????{
????????????????Drag();
????????????}
????????}

????????private?void?WheelArea_MouseUp(object?sender,?MouseButtonEventArgs?e)
????????{
????????????if?(e.ChangedButton?==?MouseButton.Left?&&?_dragMode)
????????????{
????????????????EndDrag();
????????????}
????????}

????????private?void?WheelArea_MouseWheel(object?sender,?MouseWheelEventArgs?e)
????????{
????????????if?(_dragMode)?return;

????????????int?offset?=?e.Delta?/?120;
????????????if?(offset?<?0?&&?Value?>?MinValue)
????????????{
????????????????Value?+=?offset;
????????????????UpdateProgress();
????????????????_wheelLayer.AngleOffset?-=?offset?*?_wheelSpeed;
????????????????_wheelLayer.UpdateLayer();
????????????}
????????????else?if?(offset?>?0?&&?Value?<?MaxValue)
????????????{
????????????????Value?+=?offset;
????????????????UpdateProgress();
????????????????_wheelLayer.AngleOffset?-=?offset?*?_wheelSpeed;
????????????????_wheelLayer.UpdateLayer();
????????????}
????????}

????????#endregion

????????#region?鼠標操作

????????private?void?BeginDrag()
????????{
????????????_dragMode?=?true;
????????????WheelArea.CaptureMouse();

????????????_dragStart?=?Mouse.GetPosition(WheelArea);
????????????_angleStart?=?_wheelLayer.AngleOffset;

????????????_valueStart?=?Value;
????????????_offsetDown?=?Value?-?MinValue;
????????????_offsetUp?=?Value?-?MaxValue;
????????}

????????private?void?Drag()
????????{
????????????double?offset_y?=?Mouse.GetPosition(WheelArea).Y?-?_dragStart.Y;
????????????if?(offset_y?<?_offsetUp)?offset_y?=?_offsetUp;
????????????else?if?(offset_y?>?_offsetDown)?offset_y?=?_offsetDown;

????????????double?offset_angle?=?offset_y?*?_wheelSpeed;
????????????Value?=?_valueStart?-?(int)offset_y;
????????????_wheelLayer.AngleOffset?=?_angleStart?+?offset_angle;
????????????UpdateProgress();
????????????_wheelLayer.UpdateLayer();
????????}

????????private?void?EndDrag()
????????{
????????????_dragMode?=?false;
????????????WheelArea.ReleaseMouseCapture();
????????}

????????#endregion

????????#region?私有方法

????????///?<summary>
????????///?初始化圖層
????????///?</summary>
????????private?void?InitLayer()
????????{
????????????_wheelLayer.Width?=?LayerBox.ActualWidth;
????????????_wheelLayer.Height?=?LayerBox.ActualHeight;
????????????LayerBox.Children.Add(_wheelLayer);
????????????_wheelLayer.Init();
????????????_wheelLayer.UpdateLayer();
????????}

????????///?<summary>
????????///?更新進度
????????///?</summary>
????????private?void?UpdateProgress()
????????{
????????????Grid_Value.Height?=?(double)(Value?-?MinValue)?/?(MaxValue?-?MinValue)?*?180;
????????}

????????#endregion

????????#region?字段

????????private?readonly?WheelLayer?_wheelLayer?=?new?WheelLayer();

????????private?Point?_dragStart?=?new?Point();
????????private?double?_angleStart?=?0;
????????private?int?_valueStart?=?0;
????????private?bool?_dragMode?=?false;

????????///?<summary>滾輪速度</summary>
????????private?readonly?double?_wheelSpeed?=?0.7;

????????///?<summary>最大向上偏移</summary>
????????private?double?_offsetUp;
????????///?<summary>最大向下偏移</summary>
????????private?double?_offsetDown;

????????#endregion
????}
}

3）創(chuàng)建 WheelLayer.cs 代碼如下:

using?MathUtil;
using?System;
using?System.Collections.Generic;
using?System.Runtime.CompilerServices;
using?System.Windows;
using?System.Windows.Media;
using?WpfUtil;

namespace?TopControl
{
????public?class?WheelLayer?:?SingleLayer
????{
????????#region?屬性

????????///?<summary>槽高度：180px -?上下邊框（4px）</summary>
????????public?int?GrooveHeight?{?get;?set;?}?=?176;

????????///?<summary>角度：圓弧切線與槽邊的夾角</summary>
????????public?int?Angle?{?get;?set;?}?=?90;

????????///?<summary>刻度線數(shù)量</summary>
????????public?int?LineCount?{?get;?set;?}?=?90;

????????///?<summary>角度偏移</summary>
????????public?double?AngleOffset?{?get;?set;?}?=?0;

????????#endregion

????????#region?公開方法

????????public?override?void?Init()
????????{
????????????//?起點、終點、中點
????????????Point2D?startPoint?=?new?Point2D(0,?0);
????????????Point2D?endPoint?=?new?Point2D(GrooveHeight,?0);
????????????Point2D?centerPoint?=?startPoint.CenterWith(endPoint);
????????????//?向量：中點?->?起點
????????????Vector2?centerToStart?=?new?Vector2(centerPoint,?startPoint);
????????????centerToStart.Rotate(-90);
????????????//?向量：終點?->?中點
????????????Vector2?endToCenter?=?new?Vector2(endPoint,?centerPoint);
????????????endToCenter.Rotate(-90?+?Angle);
????????????//?圓心
????????????_circleCenter?=?centerToStart.IntersectionWith(endToCenter);
????????????//?向量：圓心?->?起點
????????????Vector2?vector?=?new?Vector2(_circleCenter,?startPoint);
????????????_radius?=?vector.Distance;
????????????_anglePerLine?=?360.0?/?LineCount;
????????}

????????protected?override?void?OnUpdate()
????????{
????????????//?最高點
????????????Point2D?top?=?new?Point2D(_circleCenter.X,?_circleCenter.Y?-?_radius);
????????????//?向量：圓心?->?最高點
????????????Vector2?vector?=?new?Vector2(_circleCenter,?top);
????????????double?max?=?Math.Abs(vector.Target.Y);
????????????//?偏移角度
????????????vector.Rotate(AngleOffset);
????????????//?開始旋轉(zhuǎn)計算刻度位置
????????????List<Point2D>?pointList?=?new?List<Point2D>();
????????????for?(int?counter?=?0;?counter?<?LineCount;?counter++)
????????????{
????????????????if?(vector.Target.Y?<?0)?pointList.Add(vector.Target);
????????????????vector.Rotate(-_anglePerLine);
????????????}

????????????//?繪制刻度線
????????????foreach?(var?item?in?pointList)
????????????????DrawHorizontalLine(item.X,?Math.Abs(item.Y)?/?max);
????????}

????????#endregion

????????#region?私有方法

????????///?<summary>
????????///?繪制水平線
????????///?</summary>
????????[MethodImpl(MethodImplOptions.AggressiveInlining)]
????????private?void?DrawHorizontalLine(double?y,?double?opacity)
????????{
????????????Pen?pen?=?new?Pen(new?SolidColorBrush(Color.FromArgb((byte)(opacity?*?255),?32,?32,?32)),?1);
????????????Pen?pen2?=?new?Pen(new?SolidColorBrush(Color.FromArgb((byte)(opacity?*?255),?64,?64,?64)),?1);
????????????_dc.DrawLine(pen,?new?Point(2,?y?-?0.5),?new?Point(Width?-?2,?y?-?0.5));
????????????_dc.DrawLine(pen2,?new?Point(2,?y?+?0.5),?new?Point(Width?-?2,?y?+?0.5));
????????}

????????#endregion

????????#region?字段

????????///?<summary>圓心</summary>
????????private?Point2D?_circleCenter?=?new?Point2D(0,?0);
????????///?<summary>半徑</summary>
????????private?double?_radius?=?0;
????????///?<summary>刻度線之間的夾角</summary>
????????private?double?_anglePerLine?=?0;

????????#endregion
????}
}

4）創(chuàng)建 WheelExample.xaml 代碼如下:

<wd:Window?x:Class="TopControl.MainWindow"
????????xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
????????xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
????????xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
????????xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
????????xmlns:local="clr-namespace:TopControl"
????????xmlns:wd="https://github.com/WPFDevelopersOrg/WPFDevelopers"
????????mc:Ignorable="d"?Background="#1e1e1e"
????????Title="https://github.com/WPFDevelopersOrg/SimulationControl?-?俞宏偉"?Height="450"?Width="800">
????<Grid>
????????<local:Wheel?HorizontalAlignment="Left"?VerticalAlignment="Top"?Margin="50"/>
????</Grid>
</wd:Window>

效果圖