Re: can not find GetPointAtFractionLength Method in Silverlight.

08-18-2008 4:31 AM |

Unfortunately this method is not available in Silverlight. For this particular scenario, you can use the following code to turn the EllipseGeometry into a PathGeometry that contains a series of LineSegments:

PathGeometry pg = new PathGeometry();
PathFigure pf = new PathFigure();
pf.StartPoint = new Point(125, 60);
for (double i = 0; i <= 2 * Math.PI; i += 0.01)
{
LineSegment ls = new LineSegment();
double x = 60 + 65 * Math.Cos(i);
double y = 60 + 65 * Math.Sin(i);
ls.Point = new Point(x, y);
pf.Segments.Add(ls);
}
LineSegment lsEnd = new LineSegment();
lsEnd.Point = new Point(125, 60);
pf.Segments.Add(lsEnd);
pg.Figures.Add(pf);

 

It's not difficult to write a reusable method based on this code for an EllipseGeometry. But if you want a solution for an arbitrary Geometry, you need to write more code. I think it's not difficult. You can enumerate all Geometries in Silverlight: Line/Rectangle/Ellipse/PathGeometry. And PathGeometry can contain Arc/Bezire/Line/PolyBezire/PolyLine/PolyQuadraticBezire/QuadraticSegments. None of those geometries/segments has complex formulas. So just spend some time to build a robust solution.