调用Google Directions API表单Xamarin.Forms应用

Question

I'm trying to set up a basic app to call the Google Directions API from a Xamarin.Forms app in Android. I'm new to Xamarin & C# generally, so have struggled searching for the right terms, but am familiar with the directions service from a javascript angle.

I'm using this basic app as a test bed: https://docs.microsoft.com/en-us/xamarin/android/platform/maps-and-location/maps/maps-api

I can add the button and associate a process with it, but how do i call the API & catch the results?

I'll worry about plotting etc later, i just want to write out the results to console for now.

Thanks for your help in advance!

Answer 1

1.First of all, you can used following URL to get Json data.(Please notice:You need to enable the Directions API in Google console,otherwise, you will get error message This API project is not authorized to use this API. )

https://maps.googleapis.com/maps/api/directions/json?origin=lat1,lon1&destination=lat2,lon2&key=yourApiKey

In this URL, you need to provide the latitude and longitude of Origin position and destination postion.API key(You can get the API key from a Google console)

2.You can play and just change variables in this link and open it in browser, to see the returning object like this screenshot.

3.When you receive the return object, you will need to parse it.(Prase json data: http://bsubramanyamraju.blogspot.com/2017/04/xamarinforms-consuming-rest-webserivce_17.html )

4.The distance will be at googleApiRouteObject.routes[0].legs[0].distance; There you will find a int representation in meeters, and string representation like 2km.

5.The waypoints will be coded in Polylines, you will need to parse them. You can find how to do that with code examples here: https://developers.google.com/maps/documentation/utilities/polylineutility

If you want to get the sample code, you can refer to this link.

https://agileapp.co/xamarin-forms-maps-polyline-route-highlighted-google-api