问题
The requirement that I have is to have a green polyline to be showed on the map. But when the map is switched to satellite view, the green polyline becomes unclear.
I can't get the color of the polyline changed. So to distinguish the polyline from the background(Satellite view of the map), I need to draw white outline to the polyline.
I went through the documentation of GMSPolyline class and could not find anything using which I can outline the polyline with very thin two white lines.
Can anyone please give me suggestions as to how can I achieve this? (Without drawing/overlapping the main polyline with two boundary polylines)
回答1:
The easiest way I've found is to draw a fatter line underneath your main polyline, thereby adding a stroke to either side.
When you define your main polyline(s), add a zIndex:
polyline.strokeColor = [UIColor whiteColor];
polyline.strokeWidth = 2;
polyline.zIndex = 10;
polyline.map = mapView;
Then add another polyline with the same path, modifying your original's strokeWidth and zIndex:
GMSPolyline *stroke = [GMSPolyline polylineWithPath:samePathAsYourMainPolyline];
stroke.strokeColor = [UIColor blackColor];
stroke.strokeWidth = polyline.strokeWidth + 1;
stroke.zIndex = polyline.zIndex - 1;
stroke.map = mapView;
来源：https://stackoverflow.com/questions/23900703/outline-of-polyline-in-google-maps-sdk-for-ios