Features graphics Geometries

目录

• Features graphics Geometries
  • Geometries
    • Geometries的基础作用
    • Envelope
    • Point
    • Multipoint
    • Polyline
    • Polygon
    • Multipart (Polygon and Polyline)
  • Features和graphics的关系
  • Features和graphics组成
  • Features和graphics比较
  • Features和graphics的展示依赖
  • 创建features
  • 创建graphics

Features graphics Geometries

Geometries

Geometries的基础作用

Envelope

// Envelope with bounding coords defined in longitude and latitude
var areaOfInterest = new Envelope(-117.85, 32.20, -116.50, 33.45, SpatialReferences.Wgs84);

// Envelope with lower-left (southwest) and upper-right (northeast) points
var southwestPoint = new MapPoint(-117.85, 32.20, SpatialReferences.Wgs84);
var northeastPoint = new MapPoint(-116.50, 33.45, SpatialReferences.Wgs84);
var env = new Envelope(southwestPoint, northeastPoint);

Point

// create a point with x, y, and z coordinate values using the WGS 1984 coordinate system
var saltLakeCity = new MapPoint(-111.88, 40.75, 1320, SpatialReferences.Wgs84);

经纬度的话为(latitude, longitude)

Multipoint

var pointCollection = new MapPoint[] { southwestPoint, northeastPoint, saltLakeCity };
var oneMultipoint = new Multipoint(pointCollection, SpatialReferences.Wgs84);

遍历Multipoint

foreach (var pt in oneMultipoint.Points)
{
    var coordValues = string.Format("x: {0} y: {1} z: {2}", pt.X, pt.Y, pt.Z);
    Debug.WriteLine(coordValues);
}

Polyline

// define some map points (airports: LA, Chicago, Paris)
var laxPoint = new MapPoint(-118.408, 33.943, SpatialReferences.Wgs84);
var ordPoint = new MapPoint(-87.905, 41.979, SpatialReferences.Wgs84);
var orlyPoint = new MapPoint(2.379, 48.723, SpatialReferences.Wgs84);


// add the points to a collection
var stops = new MapPoint[] { laxPoint, ordPoint, orlyPoint };


// create a new Polyline from the points
var myFlightPath = new Esri.ArcGISRuntime.Geometry.Polyline(stops);

Polygon

// create a point collection; add each corner of the state of Colorado
var coloradoCorners = new Esri.ArcGISRuntime.Geometry.PointCollection(SpatialReferences.Wgs84);
coloradoCorners.Add(-109.048, 40.998);
coloradoCorners.Add(-102.047, 40.998);
coloradoCorners.Add(-102.037, 36.989);
coloradoCorners.Add(-109.048, 36.998);


// create a new polygon from the point collection
var coloradoPoly = new Esri.ArcGISRuntime.Geometry.Polygon(coloradoCorners);

Multipart (Polygon and Polyline)

// loop through all points (vertices) in all parts of a Polygon
foreach (var part in hawaiiPoly.Parts)
{
    foreach (var pt in part.Points)
    {
        // read the point coordinates
        var coordValues = string.Format("x: {0} y: {1} z: {2}", pt.X, pt.Y, pt.Z);
        Debug.WriteLine(coordValues);
    }
}

Features和graphics的关系

Features和graphics组成

Features and graphics are similar to one another in that they both have a geometry and attributes, this is represented by the geo-element interface which they both implement.

graph LR
geometry --> Features/graphics
attributes --> Features/graphics

Features和graphics比较

Features和graphics的展示依赖

graph LR
features-->Feature_layers
Feature_layers --> feature_table

graph LR
MapView -->map
MapView -->graphic_overlays
graphic_overlays-->graphics 

graphic_overlays在所有layer上面

创建features

// define an online data source (ServiceFeatureTable)
var uri = new Uri("http://sampleserver6.arcgisonline.com/arcgis/rest/services/SF311/FeatureServer/0");
var incidentsFeatureTable = new ServiceFeatureTable(uri);


// await loading of the table then check the load status
await incidentsFeatureTable.LoadAsync();
if(incidentsFeatureTable.LoadStatus == Esri.ArcGISRuntime.LoadStatus.Loaded)
{
    // create a new feature layer, pass the service feature table to the constructor
    var incidentsLayer = new Esri.ArcGISRuntime.Mapping.FeatureLayer(incidentsFeatureTable);


    // add the feature layer to the map
    MyMapView.Map.OperationalLayers.Add(incidentsLayer);
}

创建graphics

private void DrawLineGraphic(Polyline polylineShape)
{
    // get the first graphics overlay in the map view
    var myGraphics = MyMapView.GraphicsOverlays[0];


    // define a line symbol (dashed blue)
    var lineSymbol = new SimpleLineSymbol();
    lineSymbol.Color = Colors.Blue;
    lineSymbol.Style = SimpleLineSymbolStyle.Dash;
    lineSymbol.Width = 2;
         // create a new graphic; set the Geometry and Symbol
    var lineGraphic = new Esri.ArcGISRuntime.UI.Graphic();
    lineGraphic.Geometry = polylineShape;
    lineGraphic.Symbol = lineSymbol;


    // add the graphic to the graphics overlay
    myGraphics.Graphics.Add(lineGraphic);
}

视频资料