如果我有以下我的我的Canvas元素的DataContext的四个属性如何画圆弧半径和启动和停止角度
Point Center
double Radius
double StartAngle
double EndAngle
我可以划出一道弧线无任何背后额外的代码?
如果我有以下我的我的Canvas元素的DataContext的四个属性如何画圆弧半径和启动和停止角度
Point Center
double Radius
double StartAngle
double EndAngle
我可以划出一道弧线无任何背后额外的代码?
提供一个自定义组件是最好的解决方案。我这样使用它在我的代码
<Controls:Arc Center="{Binding Path=PreviousMousePositionPixels}"
Stroke="White"
StrokeDashArray="4 4"
SnapsToDevicePixels="True"
StartAngle="0"
EndAngle="{Binding Path=DeltaAngle}"
SmallAngle="True"
Radius="40"/>
SmallAngle
当真正将呈现点之间的小角度无关的 StartAngle
和EndAngle
秩序。当SmallAngle
为假时,圆弧呈现为顺时针方向的计数器 。
执行是。
using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Shapes;
public sealed class Arc : Shape
{
public Point Center
{
get { return (Point)GetValue(CenterProperty); }
set { SetValue(CenterProperty, value); }
}
// Using a DependencyProperty as the backing store for Center. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CenterProperty =
DependencyProperty.Register("Center", typeof(Point), typeof(Arc)
, new FrameworkPropertyMetadata(new Point(0, 0), FrameworkPropertyMetadataOptions.AffectsRender));
public double StartAngle
{
get { return (double)GetValue(StartAngleProperty); }
set { SetValue(StartAngleProperty, value); }
}
// Using a DependencyProperty as the backing store for StartAngle. This enables animation, styling, binding, etc...
public static readonly DependencyProperty StartAngleProperty =
DependencyProperty.Register("StartAngle", typeof(double), typeof(Arc)
, new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender));
public double EndAngle
{
get { return (double)GetValue(EndAngleProperty); }
set { SetValue(EndAngleProperty, value); }
}
// Using a DependencyProperty as the backing store for EndAngle. This enables animation, styling, binding, etc...
public static readonly DependencyProperty EndAngleProperty =
DependencyProperty.Register("EndAngle", typeof(double), typeof(Arc)
, new FrameworkPropertyMetadata(Math.PI/2.0, FrameworkPropertyMetadataOptions.AffectsRender));
public double Radius
{
get { return (double)GetValue(RadiusProperty); }
set { SetValue(RadiusProperty, value); }
}
// Using a DependencyProperty as the backing store for Radius. This enables animation, styling, binding, etc...
public static readonly DependencyProperty RadiusProperty =
DependencyProperty.Register("Radius", typeof(double), typeof(Arc)
, new FrameworkPropertyMetadata(10.0, FrameworkPropertyMetadataOptions.AffectsRender));
public bool SmallAngle
{
get { return (bool)GetValue(SmallAngleProperty); }
set { SetValue(SmallAngleProperty, value); }
}
// Using a DependencyProperty as the backing store for SmallAngle. This enables animation, styling, binding, etc...
public static readonly DependencyProperty SmallAngleProperty =
DependencyProperty.Register("SmallAngle", typeof(bool), typeof(Arc)
, new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.AffectsRender));
static Arc()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(Arc), new FrameworkPropertyMetadata(typeof(Arc)));
}
protected override Geometry DefiningGeometry
{
get
{
var a0 = StartAngle < 0 ? StartAngle + 2 * Math.PI : StartAngle;
var a1 = EndAngle < 0 ? EndAngle + 2 * Math.PI : EndAngle;
if (a1<a0)
{
a1 += Math.PI * 2;
}
SweepDirection d = SweepDirection.Counterclockwise;
bool large;
if (SmallAngle)
{
large = false;
double t = a1;
if ((a1-a0)>Math.PI)
{
d = SweepDirection.Counterclockwise;
}
else
{
d = SweepDirection.Clockwise;
}
}else{
large = (Math.Abs(a1 - a0) < Math.PI);
}
Point p0 = Center + new Vector(Math.Cos(a0), Math.Sin(a0)) * Radius;
Point p1 = Center + new Vector(Math.Cos(a1), Math.Sin(a1)) * Radius;
List<PathSegment> segments = new List<PathSegment>(1);
segments.Add(new ArcSegment(p1, new Size(Radius, Radius), 0.0, large, d, true));
List<PathFigure> figures = new List<PathFigure>(1);
PathFigure pf = new PathFigure(p0, segments, true);
pf.IsClosed = false;
figures.Add(pf);
Geometry g = new PathGeometry(figures, FillRule.EvenOdd, null);
return g;
}
}
}
谢谢你花时间发布这个。为我节省了很多时间做一个弧形动画,注意这个形状可以在XAML中用于
我可以提供一个稍微不同的解决方案吗?
class ArcII:FrameworkElement
{
/// <summary>
/// Center point of Arc.
/// </summary>
[Category("Arc")]
public Point Center
{
get { return (Point)GetValue(CenterProperty); }
set { SetValue(CenterProperty, value); }
}
// Using a DependencyProperty as the backing store for Center. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CenterProperty =
DependencyProperty.Register("Center", typeof(Point), typeof(ArcII), new FrameworkPropertyMetadata(new Point(0, 0), FrameworkPropertyMetadataOptions.AffectsRender));
/// <summary>
/// Forces the Arc to the center of the Parent container.
/// </summary>
[Category("Arc")]
public bool OverrideCenter
{
get { return (bool)GetValue(OverrideCenterProperty); }
set { SetValue(OverrideCenterProperty, value); }
}
// Using a DependencyProperty as the backing store for OverrideCenter. This enables animation, styling, binding, etc...
public static readonly DependencyProperty OverrideCenterProperty =
DependencyProperty.Register("OverrideCenter", typeof(bool), typeof(ArcII), new FrameworkPropertyMetadata((bool)false, FrameworkPropertyMetadataOptions.AffectsRender));
/// <summary>
/// Start angle of arc, using standard coordinates. (Zero is right, CCW positive direction)
/// </summary>
[Category("Arc")]
public double StartAngle
{
get { return (double)GetValue(StartAngleProperty); }
set { SetValue(StartAngleProperty, value); }
}
// Using a DependencyProperty as the backing store for StartAngle. This enables animation, styling, binding, etc...
public static readonly DependencyProperty StartAngleProperty =
DependencyProperty.Register("StartAngle", typeof(double), typeof(ArcII), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.AffectsRender));
/// <summary>
/// Length of Arc in degrees.
/// </summary>
[Category("Arc")]
public double SweepAngle
{
get { return (double)GetValue(SweepAngleProperty); }
set { SetValue(SweepAngleProperty, value); }
}
// Using a DependencyProperty as the backing store for SweepAngle. This enables animation, styling, binding, etc...
public static readonly DependencyProperty SweepAngleProperty =
DependencyProperty.Register("SweepAngle", typeof(double), typeof(ArcII), new FrameworkPropertyMetadata((double)180, FrameworkPropertyMetadataOptions.AffectsRender));
/// <summary>
/// Size of Arc.
/// </summary>
[Category("Arc")]
public double Radius
{
get { return (double)GetValue(RadiusProperty); }
set { SetValue(RadiusProperty, value); }
}
// Using a DependencyProperty as the backing store for Radius. This enables animation, styling, binding, etc...
public static readonly DependencyProperty RadiusProperty =
DependencyProperty.Register("Radius", typeof(double), typeof(ArcII), new FrameworkPropertyMetadata(10.0, FrameworkPropertyMetadataOptions.AffectsRender));
[Category("Arc")]
public Brush Stroke
{
get { return (Brush)GetValue(StrokeProperty); }
set { SetValue(StrokeProperty, value); }
}
// Using a DependencyProperty as the backing store for Stroke. This enables animation, styling, binding, etc...
public static readonly DependencyProperty StrokeProperty =
DependencyProperty.Register("Stroke", typeof(Brush), typeof(ArcII), new FrameworkPropertyMetadata((Brush)Brushes.Black,FrameworkPropertyMetadataOptions.AffectsRender));
[Category("Arc")]
public double StrokeThickness
{
get { return (double)GetValue(StrokeThicknessProperty); }
set { SetValue(StrokeThicknessProperty, value); }
}
// Using a DependencyProperty as the backing store for StrokeThickness. This enables animation, styling, binding, etc...
public static readonly DependencyProperty StrokeThicknessProperty =
DependencyProperty.Register("StrokeThickness", typeof(double), typeof(ArcII), new FrameworkPropertyMetadata((double)1,FrameworkPropertyMetadataOptions.AffectsRender));
protected override void OnRender(DrawingContext dc)
{
base.OnRender(dc);
Draw(dc);
}
private void Draw(DrawingContext dc)
{
Point center = new Point();
if (OverrideCenter)
{
Rect rect = new Rect(RenderSize);
center = Polar.CenterPointFromRect(rect);
}
else
{
center = Center;
}
Point startPoint = Polar.PolarToCartesian(StartAngle, Radius, center);
Point endPoint = Polar.PolarToCartesian(StartAngle + SweepAngle, Radius, center);
Size size = new Size(Radius, Radius);
bool isLarge = (StartAngle + SweepAngle) - StartAngle > 180;
List<PathSegment> segments = new List<PathSegment>(1);
segments.Add(new ArcSegment(endPoint, new Size(Radius, Radius), 0.0, isLarge, SweepDirection.Clockwise, true));
List<PathFigure> figures = new List<PathFigure>(1);
PathFigure pf = new PathFigure(startPoint, segments, true);
pf.IsClosed = false;
figures.Add(pf);
Geometry g = new PathGeometry(figures, FillRule.EvenOdd, null);
dc.DrawGeometry(null, new Pen(Stroke,StrokeThickness), g);
}
}
用法:
<!--Centerd on Parent-->
<local:ArcII Center="0,0"
OverrideCenter="True"
StartAngle="150"
SweepAngle="240"
Radius="100"
Stroke="Red"
StrokeThickness="3"
/>
<!--Centerd on Parent-->
<local:ArcII Center="0,0"
OverrideCenter="True"
StartAngle="150"
SweepAngle="240"
Radius="95"
Stroke="Red"
StrokeThickness="3"
/>
<!--Centerd on Parent-->
<local:ArcII Center="0,0"
OverrideCenter="True"
StartAngle="150"
SweepAngle="240"
Radius="90"
Stroke="Red"
StrokeThickness="3"
/>
<!--Centerd on Point-->
<local:ArcII Center="0,150"
OverrideCenter="False"
StartAngle="270"
SweepAngle="180"
Radius="100"
/>
<!--Centerd on Point-->
<local:ArcII Center="525,150"
OverrideCenter="False"
StartAngle="90"
SweepAngle="180"
Radius="100"
/>
注: A)这不会做360 SweepAngle,对于使用的椭圆。 B)OverrideCenter:这将弧的中心放在其父项的中心。请注意像网格这样的元素可以被分区,但仍然有一个中心,这可能不是弧所在的列或行。
也许[this](http://stackoverflow.com/questions/6744350/how -can-i-draw-a-circle-sector-with-the-ellipse-class)很有用 – dkozl
差不多,但我仍然需要手动计算代码背后或视图模型中弧段的起点和终点。我可以那样做,但希望我不必这样做。 :( – bradgonesurfing
我可能只是像这里定义一个自定义的弧形状http://stackoverflow.com/questions/12374643/wpf-custom-shape – bradgonesurfing