Google Map Api V3 系列之 导航(包括清除线路)

function NavigationTool() {
           var mode = google.maps.DirectionsTravelMode.DRIVING; //谷歌地图路线指引的模式
           var directionsDisplay = new google.maps.DirectionsRenderer();   //地图路线显示对象
           var directionsService = new google.maps.DirectionsService();    //地图路线服务对象
           var directionsVisible = false;  //是否显示路线
           directionsDisplay.setMap(null);
           directionsDisplay.setMap(map);
           var Navigpoints = []; //起终点
           google.maps.event.addListener(map, "click", function(evt) {
               if (Navigpoints.length == 0) {
                   if (confirm("是否将当前点设为起点？")) {
                       Navigpoints.push(evt.latLng);
                   }
               } else {
                   if (Navigpoints.length >= 2) { points = []; google.maps.event.clearListeners(map, "click"); return; }
                   if (confirm("是否将当前点设为终点？")) {
                       Navigpoints.push(evt.latLng);
                       var request = {
                           origin: Navigpoints[0], //起点
                           destination: Navigpoints[1], //终点
                           travelMode: mode,
                           optimizeWaypoints: true,
                           avoidHighways: false,
                           avoidTolls: false
                       };
                       directionsService.route(
                        request,
                        function(response, status) {
                            if (status == google.maps.DirectionsStatus.OK) {
                                directionsDisplay.setDirections(response);
                                //定时清除线路
                                setTimeout(function() { directionsDisplay.setMap(null) }, 8000);
                            }
                        }
                    );
                   }
               }

           });
           directionsVisible = true;
       }