我创建一个使用谷歌地图API的android一个Android应用程序。结果这个应用程序需要有一个对点击多边形的功能,但因为它不适用于谷歌地图Android的API V2。我做了一些研究,发现一个变通此功能。结果我结束了同是检查点是否在多边形的方法。结果我使用这个库。而且它的工作pretty好,如果你手工创建的界限。结果如果可以创建能够解决我的问题一个循环的界限。结果我从数据库中获取的多边形点。
I creating a android app that uses google maps android api. This app need to to have a on click polygon function, but since it not available on google maps android api v2. I did some research and found a work around for this function. What i ended up with is to check if a point is in a polygon method. I'm using this library. And it work pretty well if you create the bounds manually. If can create the bounds in a loop that would solve my problem. I get the polygon points from my database.
下面是我的MapFragment code:
Here is my MapFragment code:
public class MapBlocksMapView extends Fragment {
protected GoogleMap googleMap;
protected LatLng latLng;
protected Intent intent;
protected String color, crops, block_code, tmp_user;
public MapBlocksMapView() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ActionBar actionBar = getActivity().getActionBar();
actionBar.setTitle("Block View");
View rootView = inflater.inflate(R.layout.fragment_blocksmapview, container, false);
if (googleMap== null) {
googleMap= ((SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map)).getMap();
}
Bundle bundle = getArguments();
if (bundle != null) {
block_code = bundle.getString("block_code");
tmp_user = bundle.getString("user");
}
googleMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng latLng) {
checkpoint(latLng.latitude, latLng.longitude);
}
});
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState){
getdata(getActivity(), block_code);
super.onActivityCreated(savedInstanceState);
}
private void checkpoint(double latitude, double longitude) {
System.out.println(latitude +"," +longitude);
}
public void getdata(Context ctx, String block_code) {
SQLHelper dbhelper = new SQLHelper(ctx);
dbhelper.getReadableDatabase();
JSONArray jsonArray = dbhelper.getSingleBlocks(block_code);
try {
for (int a = 0; a < jsonArray.length(); a++) {
JSONObject jsonObject = new JSONObject(String.valueOf(jsonArray.getJSONObject(a)));
JSONArray jsonArray1 = jsonObject.getJSONArray("b_points");
if (jsonObject.getJSONArray("b_points").length() > 0) {
color = jsonObject.getString("b_color");
crops = jsonObject.getString("b_crop");
PolygonOptions rectOptions = new PolygonOptions();
for (int b = 0; b < jsonArray1.length(); b++) {
JSONArray jsonArray2 = jsonArray1.getJSONArray(b);
rectOptions.add(new LatLng(jsonArray2.getDouble(0), jsonArray2.getDouble(1)));
System.out.println(jsonArray2.get(0) + " / " + jsonArray2.get(1));
}
latLng = new LatLng(jsonArray1.getJSONArray(0).getDouble(0), jsonArray1.getJSONArray(0).getDouble(1));
rectOptions.strokeWidth(1).strokeColor(Color.parseColor(color)).fillColor(Color.parseColor(color));
googleMap.addPolygon(rectOptions);
CameraUpdate cameraPosition = CameraUpdateFactory.newLatLngZoom(latLng, 17);
googleMap.animateCamera(cameraPosition);
} else {
Toast.makeText(getActivity(), "Error with the selected block", Toast.LENGTH_LONG).show();
closeFragment();
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onDestroyView() {
super.onDestroyView();
SupportMapFragment f = (SupportMapFragment) getFragmentManager()
.findFragmentById(R.id.map);
if (f != null)
getFragmentManager().beginTransaction().remove(f).commit();
}
private void closeFragment() {
getActivity().getFragmentManager().popBackStack();
}
}
下面是从图书馆的例子code:
Here is the example code from the library:
Polygon polygon = Polygon.Builder()
.addVertex(new Point(1, 3))
.addVertex(new Point(2, 8))
.addVertex(new Point(5, 4))
.addVertex(new Point(5, 9))
.addVertex(new Point(7, 5))
.addVertex(new Point(6, 1))
.addVertex(new Point(3, 1))
.build();
Point point = new Point(4.5f, 7);
boolean contains = polygon.contains(point);
如果一些有其他的解决方案或建议将是有益的。结果谢谢
If some have a other solution or suggestions would be helpful. Thanks
我管理的一些周围挖后解决了这个发现在GitHub上这个code。结果我使用这个库现在,它就像一个魅力。
I manage to solve this after some digging around and found this code on github. I'm using this library now and it works like a charm.
我的多边形点存储像这样在我的数据库字符串。
My polygon points are stored like this in my database as string.
[[3.65E-4,-1.1E-5],[-5.0E-6,3.54E-4],[-3.0E-6,-1.1E-4]]
下面是一个例子code
Here is a example code
protected double[] points;
public void getdata(){
SQLHelper dbhelper = new SQLHelper(ctx);
dbhelper.getReadableDatabase();
String[] ls =dbhelper.getSingleBlocksPointsArray(block_code)
.replaceAll("\\[", "")
.replaceAll("\\]","")
.split(",");
points = new double[ls.length];
for(int i=0;i<ls.length;i++)
{
points[i] = Double.parseDouble(ls[i]);
}
}
在onCreateView我用这个:
in onCreateView i use this:
googleMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng latLng) {
if(contains(new Coordinate(latLng.latitude,latLng.longitude), points)) {
Toast.makeText(getActivity(),"True",Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(getActivity(),"False",Toast.LENGTH_SHORT).show();
}
}
});