web端使用谷歌地图限制地图拖动范围

			//配置地图的拖动限制范围。
			var leftLowerLimitX =31.101783284242128;
            var leftLowerLimitY =117.33213196289057;
            var rightUpperLimitX =34.529788977139795;
            var rightUpperLimitY =121.39981995117182;
            var strictBounds = new google.maps.LatLngBounds(
                new google.maps.LatLng(leftLowerLimitX, leftLowerLimitY), //左下
                new google.maps.LatLng(rightUpperLimitX, rightUpperLimitY)//右上
            );
            google.maps.event.addListener(map, 'drag', function () {
                if (strictBounds.contains(map.getCenter())) {
                    return;
                }
                layer.msg('拖动范围已经超出限制', function () {
                });
                map.setCenter(new google.maps.LatLng(centX,centY));
            });