我試圖在動態地圖服務圖層上使用識別工具,並顯示一個信息窗口,顯示附加到記錄的圖像。我不得不四處尋找並獲取要素圖層,但這很好。我遇到延期問題。ArcGIS Javascript識別任務和延期
下面是問題:標識任務返回一個dojo延遲對象。我有一個回調,當延期解決時運行。在該回調函數中,我運行了另一個名爲queryAttachmentInfos的函數。運行時,「返回功能」行將在queryAttachmentInfos函數之前觸發。我不知道爲什麼。不應該在回調中發生所有事情嗎?如何使回調函數等待queryAttachmentInfo完成?我正在使用setTimeout強制腳本等待一秒鐘,這有時會起作用,但我知道這不是一個好的解決方案。
任何幫助將受到歡迎。下面
代碼...
function executeIdentifyTask(evt) {
identifyParams.geometry = evt.mapPoint;
identifyParams.mapExtent = map.extent;
var deferred = identifyTask.execute(identifyParams);
deferred.addCallback(function(response) {
return dojo.map(response, function(result) {
var feature = result.feature;
var fLayerPath = "http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/SanFrancisco/311Incidents/FeatureServer/0"
var featureLayer = new esri.layers.FeatureLayer(fLayerPath);
var objID = feature.attributes.OBJECTID;
feature.attributes.layerName = result.layerName;
//alert(result.layerId);
if(result.layerName === 'Tax Parcels'){
featureLayer.queryAttachmentInfos(6737858, function (infos) {
if (infos.length>0) {
el = document.createElement('img');
el.setAttribute('src', infos[0].url);
t = document.createElement('table');
//first row Request Type
r = t.insertRow(0);
r.bgColor="#00FFFF";
c = r.insertCell(0);
c1 = r.insertCell(1);
c.innerHTML="Request Type";
c1.innerHTML=feature.attributes.building;
//second row District
r1 = t.insertRow(-1);
c2 = r1.insertCell(0);
c2_1 = r1.insertCell(1);
c2.innerHTML="District";
c2_1.innerHTML=feature.attributes.UNIT;
//third row Status
r2 = t.insertRow(-1);
r2.bgColor="#00FFFF";
c3 = r2.insertCell(0);
c3_1 = r2.insertCell(1);
c3.innerHTML="Status";
c3_1.innerHTML=feature.attributes.PARCELID ;
var len = infos.length;
for (var i = 0; i < len;i++)
{
newRow = t.insertRow(-1);
newCell = newRow.insertCell(0);
newCell.colSpan=2;
newCell.innerHTML="<a href="+infos[i].url+"/><img src="+infos[i].url+"/>";
//els[i]= document.createElement('img');
//els[i].setAttribute('src', infos[i].url);
//alert(infos[i].url);
}
var template = new esri.InfoTemplate("", t);
feature.setInfoTemplate(template);
//return feature;
}
else
{
var template = new esri.InfoTemplate("", "${Postal Address} <br/> Different: ${First Owner Name}");
feature.setInfoTemplate(template);
//eturn feature;
}
});
console.log(feature.attributes.PARCELID);
}
else if (result.layerName === 'Building Footprints'){
var template = new esri.InfoTemplate("", "Parcel ID: ${PARCELID}");
feature.setInfoTemplate(template);
//return feature;
}
return feature;
});
});
setTimeout(function(){map.infoWindow.setFeatures([ deferred ])},1000);
map.infoWindow.show(evt.mapPoint);
}
」回調中的所有事情不應該同步發生嗎?「不必要。異步回調本身可能包含異步操作。 –