Check null

Author: rogerhu

app/src/main/java/com/example/mapdemo/MapDemoActivity.java

@@ -202,7 +202,13 @@ public void onLocationResult(LocationResult locationResult) {
     }
 
     public void onLocationChanged(Location location) {
+        // GPS may be turned off
+        if (location == null) {
+            return;
+        }
+
         // Report to the UI that the location was updated
+
         mCurrentLocation = location;
         String msg = "Updated Location: " +
                 Double.toString(location.getLatitude()) + "," +