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[深入浅出Windows 10]实现饼图控件

13.2 实现饼图控件

上一小节讲解了动态生成折线图和区域图,对于简单的图形这样通过C#代码来生成的方式是很方便的,但是当我们的图表要实现更加复杂的逻辑的时候,这种动态生成的方式就显得力不从心了,那就需要利用控件封装的方式来实现更加强大的图表控件功能。这一小节将来讲解怎样去用封装控件的方式去实现图表,用一个饼图控件作为例子进行分析讲解。

13.2.1 自定义饼图片形形状

饼图其实就是把一个圆形分成若干块,每一块代表着一个类别的数据,可以把这每一块的图形看作是饼图片形形状。要实现一个饼图控件,首先需要做的就是要实现饼图片形形状,在第4章里面讲解了实现如何实现自定义的形状,饼图片形形状也可以通过这种方式来实现。饼图片形形状有一些重要的属性,如饼图半径Radius,内圆半径InnerRadius,旋转角度RotationAngle,片形角度WedgeAngle,点innerArcStartPoint,点innerArcEndPoint,点outerArcStartPoint和点outerArcEndPoint等,这些属性的含义如图13.5所示。要绘制出这个饼图片形形状需要计算出4个点的坐标(点innerArcStartPoint,点innerArcEndPoint,点outerArcStartPoint和点outerArcEndPoint),这4的点的坐标需要通过半径和角度相关的属性计算出来。计算出这4个点的坐标的坐标之后,然后通过这4个点创建一个Path图形,这个Path图形由两条直线和两条弧线组成,形成了一个饼图片形形状。通过这种方式不仅仅把这个饼图片形形状创建好了,连这个图形在整个饼图的位置也设置好了。代码如下所示。

[深入浅出Windows 10]实现饼图控件

代码清单5-2 饼图图表(源代码:第5章/Examples_5_2)

 PiePiece.cs文件代码:自定义的饼图片形形状 ------------------------------------------------------------------------------------------------------------------     using System;     using Windows.Foundation;     using Windows.UI.Xaml;     using Windows.UI.Xaml.Media;     using Windows.UI.Xaml.Shapes;     namespace PieChartDemo     {         /// <summary>         /// 自定义的饼图片形形状         /// </summary>         class PiePiece : Path         {             #region 依赖属性             // 注册半径属性             public static readonly DependencyProperty RadiusProperty =                 DependencyProperty.Register("RadiusProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));             // 饼图半径             public double Radius             {                 get { return (double)GetValue(RadiusProperty); }                 set { SetValue(RadiusProperty, value); }             }             // 注册饼图片形点击后推出的距离             public static readonly DependencyProperty PushOutProperty =                 DependencyProperty.Register("PushOutProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 距离饼图中心的距离             public double PushOut             {                 get { return (double)GetValue(PushOutProperty); }                 set { SetValue(PushOutProperty, value); }             }             // 注册饼图内圆半径属性             public static readonly DependencyProperty InnerRadiusProperty =                 DependencyProperty.Register("InnerRadiusProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 饼图内圆半径             public double InnerRadius             {                 get { return (double)GetValue(InnerRadiusProperty); }                 set { SetValue(InnerRadiusProperty, value); }             }             // 注册饼图片形的角度属性             public static readonly DependencyProperty WedgeAngleProperty =                 DependencyProperty.Register("WedgeAngleProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 饼图片形的角度             public double WedgeAngle             {                 get { return (double)GetValue(WedgeAngleProperty); }                 set                 {                     SetValue(WedgeAngleProperty, value);                     this.Percentage = (value / 360.0);                  }             }             // 注册饼图片形旋转角度的属性             public static readonly DependencyProperty RotationAngleProperty =                 DependencyProperty.Register("RotationAngleProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 旋转的角度             public double RotationAngle             {                 get { return (double)GetValue(RotationAngleProperty); }                 set { SetValue(RotationAngleProperty, value); }             }             // 注册中心点的X坐标属性             public static readonly DependencyProperty CentreXProperty =                 DependencyProperty.Register("CentreXProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 中心点的X坐标             public double CentreX             {                 get { return (double)GetValue(CentreXProperty); }                 set { SetValue(CentreXProperty, value); }             }             // 注册中心点的Y坐标属性             public static readonly DependencyProperty CentreYProperty =                 DependencyProperty.Register("CentreYProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 中心点的Y坐标             public double CentreY             {                 get { return (double)GetValue(CentreYProperty); }                 set { SetValue(CentreYProperty, value); }             }             // 注册该饼图片形所占饼图的百分比属性             public static readonly DependencyProperty PercentageProperty =                 DependencyProperty.Register("PercentageProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 饼图片形所占饼图的百分比             public double Percentage             {                 get { return (double)GetValue(PercentageProperty); }                 private set { SetValue(PercentageProperty, value); }             }              // 注册该饼图片形所代表的数值属性             public static readonly DependencyProperty PieceValueProperty =                 DependencyProperty.Register("PieceValueProperty", typeof(double), typeof(PiePiece),                 new PropertyMetadata(0.0));              // 该饼图片形所代表的数值             public double PieceValue             {                 get { return (double)GetValue(PieceValueProperty); }                 set { SetValue(PieceValueProperty, value); }             }             #endregion             public PiePiece()             {                 CreatePathData(0, 0);             }              private double lastWidth = 0;             private double lastHeight = 0;             private PathFigure figure;             // 在图形中添加一个点             private void AddPoint(double x, double y)             {                 LineSegment segment = new LineSegment();                 segment.Point = new Point(x + 0.5 * StrokeThickness,                     y + 0.5 * StrokeThickness);                 figure.Segments.Add(segment);             }             // 在图形中添加一条线段             private void AddLine(Point point)             {                 LineSegment segment = new LineSegment();                 segment.Point = point;                 figure.Segments.Add(segment);             }             // 在图形中添加一个圆弧             private void AddArc(Point point, Size size, bool largeArc, SweepDirection sweepDirection)             {                 ArcSegment segment = new ArcSegment();                 segment.Point = point;                 segment.Size = size;                 segment.IsLargeArc = largeArc;                 segment.SweepDirection = sweepDirection;                 figure.Segments.Add(segment);             }              private void CreatePathData(double width, double height)             {                 // 用于退出布局的循环逻辑                 if (lastWidth == width && lastHeight == height) return;                 lastWidth = width;                 lastHeight = height;                  Point startPoint = new Point(CentreX, CentreY);                 // 计算饼图片形内圆弧的开始点                 Point innerArcStartPoint = ComputeCartesianCoordinate(RotationAngle, InnerRadius);                 // 根据中心点来校正坐标的位置                 innerArcStartPoint = Offset(innerArcStartPoint,CentreX, CentreY);                 // 计算饼图片形内圆弧的结束点                 Point innerArcEndPoint = ComputeCartesianCoordinate(RotationAngle + WedgeAngle, InnerRadius);                 innerArcEndPoint = Offset(innerArcEndPoint, CentreX, CentreY);                 // 计算饼图片形外圆弧的开始点                 Point outerArcStartPoint = ComputeCartesianCoordinate(RotationAngle, Radius);                 outerArcStartPoint = Offset(outerArcStartPoint, CentreX, CentreY);                 // 计算饼图片形外圆弧的结束点                 Point outerArcEndPoint = ComputeCartesianCoordinate(RotationAngle + WedgeAngle, Radius);                 outerArcEndPoint = Offset(outerArcEndPoint, CentreX, CentreY);                 // 判断饼图片形的角度是否大于180度                 bool largeArc = WedgeAngle > 180.0;                 // 把扇面饼图往偏离中心点推出一部分                 if (PushOut > 0)                 {                     Point offset = ComputeCartesianCoordinate(RotationAngle + WedgeAngle / 2, PushOut);                      // 根据偏移量来重新设置圆弧的坐标                     innerArcStartPoint = Offset(innerArcStartPoint,offset.X, offset.Y);                     innerArcEndPoint = Offset(innerArcEndPoint,offset.X, offset.Y);                     outerArcStartPoint = Offset(outerArcStartPoint,offset.X, offset.Y);                     outerArcEndPoint = Offset(outerArcEndPoint,offset.X, offset.Y);                 }                 // 外圆的大小                 Size outerArcSize = new Size(Radius, Radius);                 // 内圆的大小                 Size innerArcSize = new Size(InnerRadius, InnerRadius);                 var geometry = new PathGeometry();                 figure = new PathFigure();                 // 从内圆开始坐标开始画一个闭合的扇形图形                 figure.StartPoint = innerArcStartPoint;                 AddLine(outerArcStartPoint);                 AddArc(outerArcEndPoint, outerArcSize, largeArc, SweepDirection.Clockwise);                 AddLine(innerArcEndPoint);                 AddArc(innerArcStartPoint, innerArcSize, largeArc, SweepDirection.Counterclockwise);                 figure.IsClosed = true;                 geometry.Figures.Add(figure);                 this.Data = geometry;             }              protected override Size MeasureOverride(Size availableSize)             {                 return availableSize;             }              protected override Size ArrangeOverride(Size finalSize)             {                 CreatePathData(finalSize.Width, finalSize.Height);                 return finalSize;             }             //把点进行偏移转换             private Point Offset(Point point, double offsetX, double offsetY)             {                 point.X += offsetX;                 point.Y += offsetY;                 return point;             }             /// <summary>             /// 根据角度和半径来计算出圆弧上的点的坐标             /// </summary>             /// <param name="angle">角度</param>             /// <param name="radius">半径</param>             /// <returns>圆弧上的点坐标</returns>             private Point ComputeCartesianCoordinate(double angle, double radius)             {                 // 转换成弧度单位                 double angleRad = (Math.PI / 180.0) * (angle - 90);                 double x = radius * Math.Cos(angleRad);                 double y = radius * Math.Sin(angleRad);                 return new Point(x, y);             }         }     } 

13.2.2 封装饼图控件

创建好了PiePiece形状之后,下面就要开始创建利用PiePiece形状来创建饼图控件了。创建饼图控件是通过UserControl控件来实现,UserControl控件的XAML代码里面只有一个Grid面板,是用来加载PiePiece形状来组成饼图。XAML代码如下所示:

 PiePlotter.xaml文件代码 ------------------------------------------------------------------------------------------------------------------     <UserControl x:Class="PieChartDemo.PiePlotter"         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"         mc:Ignorable="d"         FontFamily="{StaticResource PhoneFontFamilyNormal}"         FontSize="{StaticResource PhoneFontSizeNormal}"         Foreground="{StaticResource PhoneForegroundBrush}"         d:DesignHeight="480" d:DesignWidth="480" >         <Grid x:Name="LayoutRoot"></Grid>     </UserControl> 

在实现饼图之前,需要知道饼图里面的数据集合的,还需要用一个实体类PieDataItem来表示饼图的数据项,有两个属性一个是表示图形的数值Value属性,另外一个是表示饼图片形块的颜色Brush属性。PieDataItem代码如下:

 PieDataItem.cs文件代码 ------------------------------------------------------------------------------------------------------------------     using Windows.UI.Xaml.Media;     namespace PieChartDemo     {         /// <summary>         /// 饼图数据实体         /// </summary>         public class PieDataItem         {             public double Value { get; set; }             public SolidColorBrush Brush { get; set; }         }     } 

下面来实现饼图控件加载的逻辑,在饼图控件里面还需要自定义一些相关的属性,用来传递相关的参数。属性HoleSize表示饼图内圆的大小,按照比例来计算;属性PieWidth表示饼图的宽度。饼图的数据集合是通过控件的数据上下文属性DataContext属性来传递,在初始化饼图的时候需要把DataContext的数据读取出来然后再创建PiePiece图形。每个PiePiece图形都添加了Tap事件,用来实现当用户点击饼图的时候,相应的某一块回往外推出去。代码如下所示:

 PiePlotter.xaml.cs文件代码 ------------------------------------------------------------------------------------------------------------------     using System.Collections.Generic;     using Windows.UI.Xaml;     using Windows.UI.Xaml.Controls;     using Windows.UI.Xaml.Input;      namespace PieChartDemo     {         /// <summary>         /// 饼图控件         /// </summary>         public partial class PiePlotter : UserControl         {              #region dependency properties             // 注册内圆大小属性             public static readonly DependencyProperty HoleSizeProperty =                             DependencyProperty.Register("HoleSize", typeof(double), typeof(PiePlotter), new PropertyMetadata(0.0));             // 内圆的大小,按照比例来计算             public double HoleSize             {                 get { return (double)GetValue(HoleSizeProperty); }                 set                 {                     SetValue(HoleSizeProperty, value);                 }             }             // 注册饼图宽度属性             public static readonly DependencyProperty PieWidthProperty =                    DependencyProperty.Register("PieWidth", typeof(double), typeof(PiePlotter), new PropertyMetadata(0.0));              // 饼图宽度             public double PieWidth             {                 get { return (double)GetValue(PieWidthProperty); }                 set { SetValue(PieWidthProperty, value); }             }              #endregion             // 饼图的片形PiePiece的集合             private List<PiePiece> piePieces = new List<PiePiece>();             // 选中的当前饼图的数据项             private PieDataItem CurrentItem;              public PiePlotter()             {                 InitializeComponent();             }              // 初始化展示饼图的方法             public void ShowPie()             {                 // 获取控件的数据上下文,转化成数据集合                 List<PieDataItem> myCollectionView = (List<PieDataItem>)this.DataContext;                 if (myCollectionView == null)                     return;                 // 半径的大小                 double halfWidth = PieWidth / 2;                  // 内圆半径大小                 double innerRadius = halfWidth * HoleSize;                 // 计算图表数据的总和                 double total = 0;                 foreach (PieDataItem item in myCollectionView)                 {                     total += item.Value;                 }                 // 通过PiePiece构建饼图                 LayoutRoot.Children.Clear();                 piePieces.Clear();                 double accumulativeAngle = 0;                 foreach (PieDataItem item in myCollectionView)                 {                     bool selectedItem = item == CurrentItem;                     double wedgeAngle = item.Value * 360 / total;                     // 根据数据来创建饼图的每一块图形                     PiePiece piece = new PiePiece()                     {                         Radius = halfWidth,                         InnerRadius = innerRadius,                         CentreX = halfWidth,                         CentreY = halfWidth,                         PushOut = (selectedItem ? 10.0 : 0),                         WedgeAngle = wedgeAngle,                         PieceValue = item.Value,                         RotationAngle = accumulativeAngle,                         Fill = item.Brush,                         Tag = item                     };                     // 添加饼图片形的点击事件                     piece.Tapped += piece_Tapped;                     piePieces.Add(piece);                     LayoutRoot.Children.Add(piece);                     accumulativeAngle += wedgeAngle;                 }             }                      void piece_Tapped(object sender, TappedRoutedEventArgs e)             {                 PiePiece piePiece = sender as PiePiece;                 CurrentItem = piePiece.Tag as PieDataItem;                 ShowPie();             }         }     } 

在调用饼图控件时需要引用控件所属的空间,然后在XAML上调用饼图控件。

 MainPage.xaml文件主要代码 ------------------------------------------------------------------------------------------------------------------     ……省略若干代码 xmlns:local="using:PieChartDemo"     ……省略若干代码     <local:PiePlotter x:Name="piePlotter" Width="400" Height="400" PieWidth="400" HoleSize="0.2"></local:PiePlotter> 

在C#代码里面,对饼图的DataContext属性进行赋值饼图的数据集合,然后调用ShowPie方法初始化饼图。代码如下:

 MainPage.xaml.cs文件主要代码 ------------------------------------------------------------------------------------------------------------------     public MainPage()     {         InitializeComponent();         List<PieDataItem> datas=new List<PieDataItem>();         datas.Add(new PieDataItem{ Value=30, Brush = new SolidColorBrush(Colors.Red)});         datas.Add(new PieDataItem { Value = 40, Brush = new SolidColorBrush(Colors.Orange) });         datas.Add(new PieDataItem { Value = 50, Brush = new SolidColorBrush(Colors.Blue) });         datas.Add(new PieDataItem { Value = 30, Brush = new SolidColorBrush(Colors.LightGray) });         datas.Add(new PieDataItem { Value = 20, Brush = new SolidColorBrush(Colors.Purple) });         datas.Add(new PieDataItem { Value = 40, Brush = new SolidColorBrush(Colors.Green) });         piePlotter.DataContext = datas;         piePlotter.ShowPie();     } 

[深入浅出Windows 10]实现饼图控件

本文来源于《深入浅出Windows 10通用应用开发》

源代码下载:http://vdisk.weibo.com/u/2186322691

目录:http://www.cnblogs.com/linzheng/p/5021428.html

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