如何让Geometry应用Transfrom

var drawingImage = new DrawingImage(drawing);
if (drawing is GeometryDrawing)
{
	var geometryDraing = (GeometryDrawing)drawing;
	var geo = geometryDraing.Geometry as PathGeometry;
	var pathGeometry = new PathGeometry();
	foreach (var figure in geo.Figures)
	{
		pathGeometry.Figures.Add(figure);
	}
	var combineGeometry = Geometry.Combine(Geometry.Empty, pathGeometry, GeometryCombineMode.Union, geometryDraing.Geometry.Transform);
	geometryDraing.Geometry = combineGeometry;
	drawing = geometryDraing;
}