javascript - 如何在 gmaps4rails v2 中添加折线

Question

我升级到最新版本的 gmaps4rails (v2)，但在绘制多段线时遇到了一些问题。

我可以使用 wiki 上的示例代码获取标记，但如果我将 addMarkers 更改为 addPolylines，则 map 中不会呈现任何内容。这是处理程序代码:

handler = Gmaps.build('Google');
handler.buildMap({ provider: {}, internal: {id: 'map'}}, function(){
polylines = handler.addPolylines([{"lat":45.678295,"lng":-121.603813,"ele":438.626221,"time":1381851321},{"lat":45.678196,"lng":-121.603607,"ele":423.202148,"time":1381851363},{"lat":45.678181,"lng":-121.603607,"ele":421.108398,"time":1381851373},{"lat":45.678162,"lng":-121.603584,"ele":420.153442,"time":1381851383},{"lat":45.678123,"lng":-121.603569,"ele":422.561096,"time":1381851393},{"lat":45.678165,"lng":-121.6036,"ele":425.191284,"time":1381851403},{"lat":45.678169,"lng":-121.603607,"ele":425.262329,"time":1381851413}]);
handler.bounds.extendWith(polylines);
handler.fitMapToBounds();
});

javascript 控制台中没有错误，只是没有 map 渲染。有什么想法吗？

Answer 1

有几件事:

• 首先是我的 2.0.0 中的一个错误，我已经升级了 2.0.3

• 然后是您的解释中的一个问题:折线是一个经纬度数组，因此您的代码无法运行。

• google 没有提供任何方式来 get the bounds of a polyline ，所以很难自动调整 map 。

也就是说，你可以这样做:

polyline = [{"lat":45.678295,"lng":-121.603813,"ele":438.626221,"time":1381851321},{"lat":45.678196,"lng":-121.603607,"ele":423.202148,"time":1381851363},{"lat":45.678181,"lng":-121.603607,"ele":421.108398,"time":1381851373},{"lat":45.678162,"lng":-121.603584,"ele":420.153442,"time":1381851383},{"lat":45.678123,"lng":-121.603569,"ele":422.561096,"time":1381851393},{"lat":45.678165,"lng":-121.6036,"ele":425.191284,"time":1381851403},{"lat":45.678169,"lng":-121.603607,"ele":425.262329,"time":1381851413}]

handler.addPolyline(polyline); // and not addPolylines
handler.bounds.extend(polyline[0]);
handler.bounds.extend(polyline[ polyline.length - 1]);
handler.fitMapToBounds();

你最终会得到: