问题描述
我在从Path绘制的画布上有弧线,其中包含以下详细信息。我想得到Point(115,225)。请查看屏幕截图以获取更多详细信息。请帮助我使公式达到目标(115,225)。
startX=250
startY=250
ArcSegment Size (70,70)
ArcSegment Point (250,200)
computation
var meanX=(startX+startX)/2-rX;//(250+250)/2-70=180
var meanY=(startY+ArcSegment.Point.Y)/2-rY;//(250+200)/2-70=225
//center Point (180,225)
//What is the formula if I want to get Point(115,225)
XAML
<Canvas Name="canvas" Background="White" Opacity="99">
<Path stroke="Blue" MouseLeftButtonDown="Path_MouseLeftButtonDown" >
<Path.Data>
<PathGeometry>
<PathfigureCollection>
<Pathfigure StartPoint="250,250" IsClosed="True">
<ArcSegment Size="70,70" IsLargeArc="True" SweepDirection="Clockwise" Point="250,200"/>
</Pathfigure>
</PathfigureCollection>
</PathGeometry>
</Path.Data>
</Path>
</Canvas>
C#
private void Path_MouseLeftButtonDown(object sender,MouseButtonEventArgs e)
{
var curve = sender as Path;
var geometry = curve.Data as PathGeometry;
var figure = geometry.figures.FirstOrDefault();
var arcSegment = figure.Segments.FirstOrDefault() as ArcSegment;
var startX = figure.StartPoint.X;
var yStart = figure.StartPoint.Y;
var startAngle = arcSegment.Point.X;
var sweepAngle = arcSegment.Point.Y;
var rX = arcSegment.Size.Width;
var rY = arcSegment.Size.Height;
var endAngle = startAngle + sweepAngle;
var meanX = (startX + startAngle) / 2 - rX;
var meanY = (yStart + sweepAngle) / 2 - rY;
}