ArcGIS Pro SDK （九）几何 7 多点

ArcGIS Pro SDK （九）几何 7 多点

文章目录

• ArcGIS Pro SDK （九）几何 7 多点
• • 1 构造多点 - 从映射点的枚举
  • 2 构造多点 - 使用 MultipointBuilderEx
  • 3 修改多点的点
  • 4 从多点检索点、2D 坐标、3D 坐标

    环境：Visual Studio 2022 + .NET6 + ArcGIS Pro SDK 3.0

    
    （图片来源网络，侵删）

    1 构造多点 - 从映射点的枚举

    // 使用 builderEx 的便捷方法或者使用 builderEx 构造函数。
    List list = new List();
    list.Add(MapPointBuilderEx.CreateMapPoint(1.0, 1.0));
    list.Add(MapPointBuilderEx.CreateMapPoint(1.0, 2.0));
    list.Add(MapPointBuilderEx.CreateMapPoint(2.0, 2.0));
    list.Add(MapPointBuilderEx.CreateMapPoint(2.0, 1.0));
    // 使用 builderEx 构造函数 - 不需要在 MCT 上运行。
    // 使用 AttributeFlags.NoAttributes - 我们在列表中有 2d 点
    MultipointBuilderEx builderEx = new MultipointBuilderEx(list, AttributeFlags.None);
    Multipoint multiPoint = builderEx.ToGeometry() as Multipoint;
    int ptCount = builderEx.PointCount;
    // builderEx 便捷方法不需要在 MCT 上运行
    multiPoint = MultipointBuilderEx.CreateMultipoint(list);
    // multiPoint.HasZ, HasM, HasID 将为 false - 属性是根据列表中点的属性状态确定的
    // 或者具体设置状态
    multiPoint = MultipointBuilderEx.CreateMultipoint(list, AttributeFlags.None);
    // multiPoint.HasM = false
    multiPoint = MultipointBuilderEx.CreateMultipoint(list, AttributeFlags.HasM);
    // multiPoint.HasM = true
    ptCount = multiPoint.PointCount;
    

    2 构造多点 - 使用 MultipointBuilderEx

    Coordinate2D[] coordinate2Ds = new Coordinate2D[] { new Coordinate2D(1, 2), new Coordinate2D(-1, -2) };
    SpatialReference sr = SpatialReferences.WGS84;
    MultipointBuilderEx builder = new MultipointBuilderEx(coordinate2Ds, sr);
    // builder.PointCount = 2
    builder.HasZ = true;
    // builder.Zs.Count = 2
    // builder.Zs[0] = 0
    // builder.Zs[1] = 0
    builder.HasM = true;
    // builder.Ms.Count = 2
    // builder.Ms[0] = NaN
    // builder.Ms[1] = NaN
    builder.HasID = true;
    // builder.IDs.Count = 2
    // builder.IDs[0] = 0
    // builder.IDs[1] = 0
    // 设置为空
    builder.SetEmpty();
    // builder.Coords.Count = 0
    // builder.Zs.Count = 0
    // builder.Ms.Count = 0
    // builder.IDs.Count = 0
    // 重置坐标
    List inCoords = new List() { new Coordinate2D(1, 2), new Coordinate2D(3, 4), new Coordinate2D(5, 6) };
    builder.Coordinate2Ds = inCoords;
    // builder.Coords.Count = 3
    // builder.HasZ = true
    // builder.HasM = true
    // builder.HasID = true
    double[] zs = new double[] { 1, 2, 1, 2, 1, 2 };
    builder.Zs = zs;   
    // builder.Zs.Count = 6
    double[] ms = new double[] { 0, 1 };
    builder.Ms = ms;   
    // builder.Ms.Count = 2
    // 坐标现在为   (x, y, z, m, id)
    //  (1, 2, 1, 0, 0), (3, 4, 2, 1, 0) (5, 6, 1, NaN, 0)
    MapPoint mapPoint = builder.GetPoint(2);
    // mapPoint.HasZ = true
    // mapPoint.HasM = true
    // mapPoint.HasID = true
    // mapPoint.Z  = 1
    // mapPoint.M = NaN
    // mapPoint.ID = 0
    // 添加一个 M 到列表
    builder.Ms.Add(2);
    // builder.Ms.count = 3
    // 坐标现在为   (x, y, z, m, id)
    //  (1, 2, 1, 0, 0), (3, 4, 2, 1, 0) (5, 6, 1, 2, 0)
    // 现在再次获取第二个点；它现在将有一个 M 值
    mapPoint = builder.GetPoint(2);
    // mapPoint.M = 2
    int[] ids = new int[] { -1, -2, -3 };
    // 分配 ID 值
    builder.IDs = ids;
    // 坐标现在为   (x, y, z, m, id)
    //  (1, 2, 1, 0, -1), (3, 4, 2, 1, -2) (5, 6, 1, 2, -3)
    // 创建一个新点
    MapPoint point = MapPointBuilderEx.CreateMapPoint(-300, 400, 4);
    builder.SetPoint(2, point);
    // 坐标现在为   (x, y, z, m, id)
    //  (1, 2, 1, 0, -1), (3, 4, 2, 1, -2) (-300, 400, 4, NaN, 0)
    builder.RemovePoints(1, 3);
    // builder.PointCount = 1
    

    3 修改多点的点

    // 假设一个多点是由 4 个点构成的
    // 修改后的多点将移除第一个点并移动最后一个点
    // 使用 builderEx 构造函数 = 不需要在 MCT 上运行。
    MultipointBuilderEx builderEx = new MultipointBuilderEx(multipoint);
    // 移除第一个点
    builderEx.RemovePoint(0);
    // 修改最后一个点的坐标
    var ptEx = builderEx.GetPoint(builderEx.PointCount - 1);
    builderEx.RemovePoint(builderEx.PointCount - 1);
    var newPtEx = MapPointBuilderEx.CreateMapPoint(ptEx.X + 1.0, ptEx.Y + 2.0);
    builderEx.AddPoint(newPtEx);
    Multipoint modifiedMultiPointEx = builderEx.ToGeometry() as Multipoint;
    

    4 从多点检索点、2D 坐标、3D 坐标

    ReadOnlyPointCollection points = multipoint.Points;
    IReadOnlyList coords2d = multipoint.Copy2DCoordinatesToList();
    IReadOnlyList coords3d = multipoint.Copy3DCoordinatesToList();