調用map.getSource（...）。setData（...）導致TypeError：無法讀取未定義的屬性「長度」

Question

我正在製作一個地圖，我正在根據數據異步創建GeoJSON圖層一個JSON API。我的初始數據加載工作，看着GeoJSON對象，它似乎得到添加額外的元素。

但是，如果我再嘗試撥打map.getSource（...）。使用setData（...）具有相同源（指向更新以GeoJSON對象中的數據元素），我得到

錯誤：類型錯誤：無法讀取性能在Actor.receive（actor.js：77）的不確定 「長度」

我可以在網上找到的唯一參考與嘗試調用使用setData上不再存在的風格或者具有無效的GeoJSON數據，但似乎並非如此 - 例如

> map.getSource("advertisers"); 
e {id: "advertisers", type: "geojson", minzoom: 0, maxzoom: 18, tileSize: 512, …} 
> features; 
(7634) [{…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, {…}, …] 
> features[0]; 
{type: "Feature", geometry: {…}, properties: {…}} 
> features[0].geometry; 
{type: "Point", coordinates: Array(2)} 
> map.getSource("advertisers").setData(features); 
e {id: "advertisers", type: "geojson", minzoom: 0, maxzoom: 18, tileSize: 512, …} 
evented.js:111 Error: TypeError: Cannot read property 'length' of undefined 
at Actor.receive (actor.js:77) 

任何建議表示讚賞。

Answer 1

看起來您正在向setData()傳遞一組功能，但您需要傳遞有效的GeoJSON對象。

，就應該替換：map.getSource("advertisers").setData(features);

有：

map.getSource("advertisers").setData({ 
    type: 'FeatureCollection', 
    features: features 
});