几何处理

降低几何体的精度

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
Point point = new Point(1.344, 2.345, 3.345, 4.345);
point.RoundXY(digits: 2);

// 1.34, 2.35, 3.345, 4.345
Console.WriteLine("{0}, {1}, {2}, {3}", point.X, point.Y, point.Z, point.M);

point.RoundZ(digits: 1);

// 1.34, 2.35, 3.3, 4.345
Console.WriteLine("{0}, {1}, {2}, {3}", point.X, point.Y, point.Z, point.M);

LineString line = new LineString();
line.AddPoint(1.2, 2.3);
line.AddPoint(2.4, 3.1);
line.RoundXY(digits: 0);

// 1, 2
Console.WriteLine("{0}, {1}", line[0].X, line[0].Y);
// 2, 3
Console.WriteLine("{0}, {1}", line[1].X, line[1].Y);

获取几何体的面积

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var triangleRing = new LinearRing();
triangleRing.AddPoint(4, 6);
triangleRing.AddPoint(1, 3);
triangleRing.AddPoint(8, 7);
triangleRing.AddPoint(4, 6);
var triangle = new Polygon(triangleRing);

var squareRing = new LinearRing();
squareRing.AddPoint(0, 9);
squareRing.AddPoint(0, 7);
squareRing.AddPoint(2, 7);
squareRing.AddPoint(2, 9);
squareRing.AddPoint(0, 9);
var square = new Polygon(squareRing);

var multiPolygon = new MultiPolygon { triangle, square };

Console.WriteLine("{0:F}", triangle.GetArea());     // 4.50
Console.WriteLine("{0:F}", square.GetArea());       // 4.00
Console.WriteLine("{0:F}", multiPolygon.GetArea()); // 8.50

获取质心

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var polygon = new Polygon();
polygon.ExteriorRing = new LinearRing(new[]
{
    new Point(1, 0),
    new Point(2, 2),
    new Point(0, 4),
    new Point(5, 5),
    new Point(6, 1),
    new Point(1, 0),
});

IPoint centroid = polygon.GetCentroid();
Console.WriteLine("{0:F} {1:F}", centroid.X, centroid.Y); // 3.33 2.58

获取几何体的凸包

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var geometry = new MultiPoint
{
    new Point(3, 2),
    new Point(0, 0),
    new Point(6, 5),
    new Point(5, 10),
    new Point(10, 0),
    new Point(8, 2),
    new Point(4, 3),
};

var convexHull = geometry.GetConvexHull();

// [0] = (0 0)
// [1] = (5 10)
// [2] = (10 0)
// [3] = (0 0)
var ring = (ILinearRing)convexHull;
for (int i = 0; i < ring.Count; ++i)
{
    Console.WriteLine("[{0}] = ({1} {2})", i, ring[i].X, ring[i].Y);
}

获取几何体的缓冲区

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var line = new LineString();
line.AddPoint(0, 0);
line.AddPoint(3, 3);

// buffer with positive distance contains all points whose distance to input geometry is less or equal to 'distance' argument.
var lineBuffer = line.GetBuffer(distance: 1);

Console.WriteLine(lineBuffer.SpatiallyContains(new Point(1, 2)));     // True
Console.WriteLine(lineBuffer.SpatiallyContains(new Point(3.1, 3.1))); // True

var polygon = new Polygon();
polygon.ExteriorRing = new LinearRing(new[]
{
    new Point(0, 0),
    new Point(0, 3),
    new Point(3, 3),
    new Point(3, 0),
    new Point(0, 0),
});

// buffer with negative distance 'shrinks' geometry.
var polygonBuffer = (IPolygon)polygon.GetBuffer(distance: -1);

// [0] = (1 1)
// [1] = (1 2)
// [2] = (2 2)
// [3] = (2 1)
// [4] = (1 1)
var ring = polygonBuffer.ExteriorRing;
for (int i = 0; i < ring.Count; ++i)
{
    Console.WriteLine("[{0}] = ({1} {2})", i, ring[i].X, ring[i].Y);
}

获取几何体的长度

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var line = new LineString();
line.AddPoint(0, 0);
line.AddPoint(2, 2);
line.AddPoint(2, 0);

Console.WriteLine("{0:F}", line.GetLength()); // 4.83

var rectangle = new Polygon(new LinearRing(new[]
{
    new Point(0, 0),
    new Point(0, 1),
    new Point(1, 1),
    new Point(1, 0),
    new Point(0, 0),

}));

// GetLength() returns perimeter for polygons
Console.WriteLine("{0:F}", rectangle.GetLength()); // 4.00

获取表面上的点

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var polygon = new Polygon();
polygon.ExteriorRing = new LinearRing(new[]
{
    new Point(0, 0),
    new Point(0, 1),
    new Point(1, 1),
    new Point(0, 0),
});

IPoint pointOnSurface = polygon.GetPointOnSurface();

// point on surface is guaranteed to be inside a polygon.
Console.WriteLine(polygon.SpatiallyContains(pointOnSurface)); // True

用线条替换多边形

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
{
    var srcGeometry = Geometry.FromText(@"GeometryCollection (POLYGON((1 2, 1 4, 3 4, 3 2)), Point (5 1))");
    var dstGeometry = srcGeometry.ReplacePolygonsByLines();
    Console.WriteLine($"source: {srcGeometry.AsText()}");
    Console.WriteLine($"result: {dstGeometry.AsText()}");
}