# android - How to bind the distance between two Markers to my polyline?

First of all I apologise for my poor English.

I currently working on an android-app and I am using the google api v2. I have got 2 Markers on my google map and calculate the distance between them, with the .distancebetween method. Then I draw a Polyline between the markers.

Now i want to bind the distance to my Polyline. The distance should be under the polyline and if i move a marker the distance should still under the polyline.

This method may help you to find the distance, it finds the distance between the starting points LatLng and ends point LatLng

``````public double CalculationByDistance(LatLng StartP, LatLng EndP) {
int Radius=6371;//radius of earth in Km
double lat1 = StartP.latitude;
double lat2 = EndP.latitude;
double lon1 = StartP.longitude;
double lon2 = EndP.longitude;
double dLat = Math.toRadians(lat2-lat1);
double dLon = Math.toRadians(lon2-lon1);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
Math.sin(dLon/2) * Math.sin(dLon/2);
double c = 2 * Math.asin(Math.sqrt(a));
double valueResult= Radius*c;
double km=valueResult/1;
DecimalFormat newFormat = new DecimalFormat("####");
int kmInDec =  Integer.valueOf(newFormat.format(km));
double meter=valueResult%1000;
int  meterInDec= Integer.valueOf(newFormat.format(meter));
Log.i("Radius Value",""+valueResult+"   KM  "+kmInDec+" Meter   "+meterInDec);

return Radius * c;
}
``````

you can also try this :

``````Location locationA = new Location("location A");

locationA.setLatitude(locationA.getLatitudeE6() / 1E6);
locationA.setLongitude(locationA.getLongitudeE6() / 1E6);

Location locationB = new Location("location B");

locationB.setLatitude(locationB.getLatitudeE6() / 1E6);
locationB.setLongitude(locationB.getLongitudeE6() / 1E6);

double distance = locationA.distanceTo(locationB);
``````

This is not easy to do, but certainly possible.

Here are the steps:

• calculate center of each line
• for that center latitude, calculate point that is 50dp below it (using `Projection`)
• put a marker on that position
• set marker icon to `Bitmap` with text
• update markers position when you get calls to `OnCameraChangeListener.onCameraChange` or in `Handler`'s `Runnable` posted every few milliseconds