问题
I am using Android Google maps v2 API and have it set up to add markers on long click. I need a way to save these markers and reload them when the app resumes again. What will be the best way to do this? Please help
Currently I add markers as follows:
map.addMarker(new MarkerOptions().position(latlonpoint)
.icon(bitmapDescriptor).title(latlonpoint.toString()));
回答1:
I got it! I can easily do this via saving the array list of points to a file and then reading them back from file
I do the following onPause
:
try {
// Modes: MODE_PRIVATE, MODE_WORLD_READABLE, MODE_WORLD_WRITABLE
FileOutputStream output = openFileOutput("latlngpoints.txt",
Context.MODE_PRIVATE);
DataOutputStream dout = new DataOutputStream(output);
dout.writeInt(listOfPoints.size()); // Save line count
for (LatLng point : listOfPoints) {
dout.writeUTF(point.latitude + "," + point.longitude);
Log.v("write", point.latitude + "," + point.longitude);
}
dout.flush(); // Flush stream ...
dout.close(); // ... and close.
} catch (IOException exc) {
exc.printStackTrace();
}
And onResume
: I do the opposite
try {
FileInputStream input = openFileInput("latlngpoints.txt");
DataInputStream din = new DataInputStream(input);
int sz = din.readInt(); // Read line count
for (int i = 0; i < sz; i++) {
String str = din.readUTF();
Log.v("read", str);
String[] stringArray = str.split(",");
double latitude = Double.parseDouble(stringArray[0]);
double longitude = Double.parseDouble(stringArray[1]);
listOfPoints.add(new LatLng(latitude, longitude));
}
din.close();
loadMarkers(listOfPoints);
} catch (IOException exc) {
exc.printStackTrace();
}
回答2:
You can implement the onLongClickListener
for the marker as below :
map.addMarker(new MarkerOptions()
.position(latlonpoint)
.icon(bitmapDescriptor)
.title(latlonpoint.toString()));
map.setOnMapLongClickListener(new OnMapLongClickListener() {
@Override
public void onMapLongClick(LatLng p_point) {
// TODO ...
}
});
来源:https://stackoverflow.com/questions/14494102/save-markers-on-android-google-maps-v2