Android GIS开发系列-- 入门季（3） GraphicsLayer添加点、线、面

GraphicsLayer是图形图层，可以自定义图形添加到地图上。调用GraphicsLayer的addGraphic方法就能添加图形，此方法要一个Graphic对象，此对象的构造方法是Graphic(Geometry geometry, Symbol symbol)，前面第一个是要素，而Geometry的子类有Envelope, MultiPath, MultiPoint, Point, Segment，Line, Polygon, Polyline。我们所常用的有点Point，线Polyline，面Polygon。而后面一

个参数是样式，点的样式是SimpleMarkerSymbol，线的样式是SimpleLineSymbol，面的样式是SimpleFillSymbol。

一、GraphicsLayer添加点：

1. Graphic graphic = new Graphic(point, new SimpleMarkerSymbol(Color.RED,5, SimpleMarkerSymbol.STYLE.CIRCLE));  
2.  graphicsLayer.addGraphic(graphic);

二、添加线，样式有实线、虚线、点虚线、点点虚线、点线等。效果图如下：

1. Polyline polyline = new Polyline();  
2.         polyline.startPath(new Point(113,23));//第一个点用startPath,后面的点用lineTo方法  
3.          polyline.lineTo(new Point(123,23));  
4.          graphic = new Graphic(polyline,new SimpleLineSymbol(Color.RED,3, SimpleLineSymbol.STYLE.SOLID));  
5.          graphicsLayer.addGraphic(graphic);

三、添加面Polygon，效果图如下：

1. Polygon polygon = new Polygon();  
2.                  //第一个点startPath,后面的点用lineTo  
3.                   polygon.startPath(new Point(118,23));  
4.                   polygon.lineTo(new Point(118,15));     
5.                   polygon.lineTo(new Point(113,13));  
6.                        
7.                 graphic = new Graphic(polygon,new SimpleFillSymbol(Color.GREEN,SimpleFillSymbol.STYLE.SOLID));  
8.                 graphicsLayer.addGraphic(graphic);

Code for all:

1. package com.arcgis.test;  
2.   
3. import android.graphics.Color;  
4. import android.os.Bundle;  
5. import android.support.annotation.Nullable;  
6. import android.support.v7.app.AppCompatActivity;  
7. import android.view.View;  
8. import android.widget.AdapterView;  
9. import android.widget.Button;  
10. import android.widget.Spinner;  
11. import com.esri.android.map.GraphicsLayer;  
12. import com.esri.android.map.MapView;  
13. import com.esri.android.map.ags.ArcGISTiledMapServiceLayer;  
14. import com.esri.android.map.event.OnSingleTapListener;  
15. import com.esri.core.geometry.Point;  
16. import com.esri.core.geometry.Polygon;  
17. import com.esri.core.geometry.Polyline;  
18. import com.esri.core.map.Graphic;  
19. import com.esri.core.symbol.SimpleFillSymbol;  
20. import com.esri.core.symbol.SimpleLineSymbol;  
21. import com.esri.core.symbol.SimpleMarkerSymbol;  
22. import java.util.ArrayList;  
23. import java.util.List;  
24.   
25.   
26. public class GraphicActivity extends AppCompatActivity {  
27.   
28.     private MapView mMapView;  
29.     private Spinner graphicTypeSpinner;  
30.     private Button clernBtn;  
31.     private ArcGISTiledMapServiceLayer arcGISTiledMapServiceLayer;  
32.     private GraphicsLayer graphicsLayer;  
33.     private String mapServerUrl = "http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer";  
34.     //点集合  
35.     private List<Point> pointList = new ArrayList<>();  
36.   
37.     private Graphic graphic;  
38.   
39.     @Override  
40.     protected void onCreate(@Nullable Bundle savedInstanceState) {  
41.         super.onCreate(savedInstanceState);  
42.         setContentView(R.layout.activity_graphic);  
43.         initView();  
44.         addLayer();  
45.     }  
46.   
47.     private void initView() {  
48.         mMapView = (MapView) findViewById(R.id.map_view);  
49.         //mapview点击事件  
50.         mMapView.setOnSingleTapListener(new OnSingleTapListener() {  
51.             @Override  
52.             public void onSingleTap(float x, float y) {  
53.                 handleSingleTap(x, y);  
54.             }  
55.         });  
56.   
57.         graphicTypeSpinner = (Spinner) findViewById(R.id.spinner_type);  
58.         graphicTypeSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {  
59.             @Override  
60.             public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {  
61.                 pointList.removeAll(pointList);  
62.                 graphicsLayer.removeAll();  
63.             }  
64.   
65.             @Override  
66.             public void onNothingSelected(AdapterView<?> parent) {  
67.   
68.             }  
69.         });  
70.   
71.         clernBtn = (Button) findViewById(R.id.clear_graphic);  
72.         clernBtn.setOnClickListener(new View.OnClickListener() {  
73.             @Override  
74.             public void onClick(View v) {  
75.                 pointList.removeAll(pointList);  
76.                 graphicsLayer.removeAll();  
77.             }  
78.         });  
79.   
80.   
81.     }  
82.   
83.   
84.     private void addLayer() {  
85.         arcGISTiledMapServiceLayer = new ArcGISTiledMapServiceLayer(mapServerUrl);  
86.         mMapView.addLayer(arcGISTiledMapServiceLayer);  
87.   
88.         graphicsLayer = new GraphicsLayer();  
89.         mMapView.addLayer(graphicsLayer);  
90.     }  
91.   
92.   
93.     private void handleSingleTap(float x, float y) {  
94.         Point point = mMapView.toMapPoint(x, y);  
95.         graphicsLayer.removeAll();  
96.         pointList.add(point);  
97.         String type = graphicTypeSpinner.getSelectedItem().toString().trim();  
98.         switch (type) {  
99.             case "点":  
100.                 graphic = new Graphic(point, new SimpleMarkerSymbol(Color.RED,5, SimpleMarkerSymbol.STYLE.CIRCLE));  
101.                 graphicsLayer.addGraphic(graphic);  
102.                 break;  
103.             case "线":  
104.                 Polyline polyline = new Polyline();  
105.                 if (pointList.size()>1){  
106.                     for(int i=0;i<pointList.size();i++){  
107.                         if (i==0){  
108.                             polyline.startPath(pointList.get(i));  
109.                         }else{  
110.                             polyline.lineTo(pointList.get(i));  
111.                         }  
112.                     }  
113.                 }  
114.                 graphic = new Graphic(polyline,new SimpleLineSymbol(Color.RED,3, SimpleLineSymbol.STYLE.SOLID));  
115.                 graphicsLayer.addGraphic(graphic);  
116.                 break;  
117.             case "面":  
118.                 Polygon polygon = new Polygon();  
119.                     for(int i=0;i<pointList.size();i++){  
120.                         if (i==0){  
121.                             polygon.startPath(pointList.get(i));  
122.                         }else{  
123.                             polygon.lineTo(pointList.get(i));  
124.                         }  
125.                     }  
126.                 graphic = new Graphic(polygon,new SimpleFillSymbol(Color.GREEN,SimpleFillSymbol.STYLE.SOLID));  
127.                 graphicsLayer.addGraphic(graphic);  
128.                 break;  
129.         }  
130.     }  
131. }