如何阻止谷歌地图渲染方向

不太确定谷歌是否会允许这么简单地克服8个路点的限制，但这里是。

我修改了__RenderRoute()，目的是:

• 构建一个包含所有directionsService数据的复合路由对象。路由段，这样…
• 返回一个承诺，该承诺在所有递归完成时被解决，或者被拒绝并带有有意义的错误消息。

主要功能__RenderRoute():

function __RenderRoute(points, i, waitTime, dfrd, errorObj) {//<<<<< Now called with a reduced number of parameters
    dfrd = dfrd || $.Deferred();
    errorObj = errorObj || {
        count: 0,
        threshold: 5//adjust as necessary
    };
    var tmpPoints = points.slice(i, i + 9);
    if (tmpPoints.length < 2) {
        if (i == 0) {//top level call
            dfrd.reject("Not enough points");
            return dfrd.promise();
        }
        else { return; }
    }
    var request = {
        origin: tmpPoints.shift().location,
        destination: tmpPoints.pop().location,
        waypoints: tmpPoints,
        travelMode: google.maps.TravelMode.DRIVING
    };
    var route = new RouteResult();//Custom object that allows successive directionsService.route results to be componded into a single route.
    var directionsService = new google.maps.DirectionsService();
    directionsService.route(request, function (result, status) {
        if (status == google.maps.DirectionsStatus.OK) {
            route.add(result);//Hopefully magic happens here.
            if(i + 9 < points.length) {
                __RenderRoute(points, i+8, 350, dfrd, errorObj);
            } else {
                dfrd.resolve(route);//<<<<< Resolve the jQuery Deferred object
            }
        } else {
            console.log("google.maps.DirectionsService status = " + status);
            if(++errorObj.count < errorObj.threshold) {
                console.log("Wait " + waitTime + " miliseconds.");
                setTimeout(function() {
                    __RenderRoute(points, i, waitTime*2, dfrd, errorObj);
                }, waitTime);
            }
            else {
                dfrd.reject('Error threshold (' + errorObj.threshold + ') exceeded'); //Reject the jQuery Deferred object
            }
        }
    });
    return dfrd;
}

在合适的范围内定义directionsDisplay:

//I think a DirectionsRenderer is reusable. If so `directionsDisplay` needs to be constructed only once as below. If not, then move this block inside foo().
var directionsDisplay = new google.maps.DirectionsRenderer({
    draggable: false,
    markerOptions: {
        visible: false
    },
    polylineOptions: {
        clickable: true,
        strokeColor: '#99F',//adjust as desired
        strokeOpacity: .6,
        strokeWeight: 6,
        zIndex: 5
    },
    preserveViewport: true
});
directionsDisplay.setMap(map);//Assumed to be defined elsewhere

在合适的范围内定义RouteResult():

/*
 * RouteResult is a utility class that will (hopefully)
 * allow several routes to be compounded into one.
 * Based on information here :
 * - https://developers.google.com/maps/documentation/javascript/directions
 * -
 * This is experimental and untested.
 */
function RouteResult() {
    var r = {
        legs: [],
        waypoint_order: [],
        overview_path: [],
        copyrights: [],
        warnings: [],
        bounds : new google.maps.LatLngBounds()//initially empty LatLngBounds obj
    };
    this.add = function (result) {
        r.legs = r.legs.concat(result.legs);
        r.waypoint_order = r.waypoint_order.concat(result.waypoint_order);
        r.overview_path = r.overview_path.concat(result.overview_path);
        r.copyrights = r.copyrights.concat(result.copyrights);
        r.warnings = r.warnings.concat(result.warnings);
        r.bounds = r.bounds.union(result.bounds);//???
        //or possibly just
        //r.bounds.union(result.bounds);//???
    };
    this.get = function() { return r; };
}

然后，调用__RenderRoute()，如下:

//foo() is an assumed function from which __RenderRoute() is called.
function foo() {
    ...
    //__RenderRoute returns a Promise, allowing `.done()` and `.fail()` to be chained.
    __RenderRoute(points, 0, 350).done(function(route) {
        directionsDisplay.setDirections(route.get());//route is a custom object. .get() returns the actuual route. 
        //You can safely call __RenderRoute() again here, eg. with `setTimeout(foo, delay)`.
    }).fail(function(errMessage) {
        console.log(errMessage);
    });
    ...
}

• 见代码注释
• 未测试，所以可能需要调试。
• 如果它不工作，也许它会给你一些想法。