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. graphic = new Graphic(polygon,new SimpleFillSymbol(Color.GREEN,SimpleFillSymbol.STYLE.SOLID));
7. graphicsLayer.addGraphic(graphic);

Code for all:

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