關於GDIRECTION的CLEAR方法

[wei]

GEvent.addListener(map, "click", clickDirection);

function clickDirection(overlay, latlng) {
directions = new GDirections(map, directionsPanel);
directions.clear();
var lat = latlng.lat();
var lng = latlng.lng();
var latlngs = latlng.lat() + "," + latlng.lng();
arrDir.push(latlngs);
directions.loadFromWaypoints(arrDir, { "avoidHighways":
true });

}

arrDir陣列宣告在FUNCTION INITIALIZE外

想請問一下為什麼這裡的CLEAR方法都沒有發揮作用
因為想要每點一次都會把上次留存的DIRECTION陸線刪掉
但是沒有作用
請問問題出在哪?

[Kevin Liu]

you are creating a new GDirections every time in the function;

you should create it once and then clear it every time, something like:

var directions = new GDirections(map, directionsPanel);

function clickDirection(overlay, latlng) {

           directions.clear();

           ...

}

2009/10/28 wei <wei...@gmail.com>

--
Kevin Tsung-Yuan Liu
Google Taipei Software Engineer

[wei]

另外想請問這樣的寫法
為什麼會造成每次SHOW出來的路徑距離都少一次
就是我click第二次秀出路徑後並沒有秀出距離
而是click第三次之後才秀出地一次到第二次的距離
請問問題是出在哪裡?

GEvent.addListener(map, "click", clickDirection);

function clickDirection(overlay, latlng) {

var lat = latlng.lat();
var lng = latlng.lng();
var latlngs = latlng.lat() + "," + latlng.lng();
arrDir.push(latlngs);

directions.loadFromWaypoints(arrDir, { "avoidHighways":
true });

var dist = directions.getDistance();
document.getElementById("Label13").innerHTML = dist.html;
}



// var dist = directions.getDistance();
// document.getElementById("Distance").innerHTML =
dist.meters;
// document.getElementById("Distance").value =
dist.meters;

}

On 10月28日, 上午6時31分, Kevin Liu <kty...@google.com> wrote:
> you are creating a new GDirections every time in the function;
> you should create it once and then clear it every time, something like:
>
> var directions = new GDirections(map, directionsPanel);
> function clickDirection(overlay, latlng) {
> directions.clear();
> ...
>
> }
>

> 2009/10/28 wei <weic...@gmail.com>

[Kevin Liu]

getting directions is not instantaneous,

you need to do something like:

GEvent.addListener(directions, "load", onGDirectionsLoad);

function onGDirectionsLoad() {

  var dist = directions.getDistance();

  document.getElementById("Label13").innerHTML = dist.html;

}

see a complete example at: http://code.google.com/intl/zh-TW/apis/maps/documentation/examples/directions-advanced.html

2009/10/28 wei <wei...@gmail.com>

[wei]

感謝你
問題解決了

On 10月28日, 下午7時03分, Kevin Liu <kty...@google.com> wrote:
> getting directions is not instantaneous,
> you need to do something like:
> GEvent.addListener(directions, "load", onGDirectionsLoad);
> function onGDirectionsLoad() {
> var dist = directions.getDistance();
> document.getElementById("Label13").innerHTML = dist.html;
>
> }
>

> see a complete example at:http://code.google.com/intl/zh-TW/apis/maps/documentation/examples/di...
>
> 2009/10/28 wei <weic...@gmail.com>