如何动态应用OpenLayers Stymbolizer上下文？

出于中详细说明的原因，我有一些样式代码如下所示：

myStyle.Events = OpenLayers.Util.extend({}, OpenLayers.Feature.Vector.style['default']);
myStyle.Events.extendDefault = true;
myStyle.Events.maxScaleDenominator = 200000000;
myStyle.Events.graphicWidth = 36;
myStyle.Events.graphicHeight = 36;
myStyle.Events.graphicOpacity = 0.75;
myStyle.Events.externalGraphic = "/img/icons/${icon}.png";
myStyle.Events.label = "${count}";
myStyle.Events.labelOutlineWidth = 1;
myStyle.Events.labelOutlineColor = "#000";
myStyle.Events.fontColor = "#000";
myStyle.Events.fontOpacity = 8.0;
myStyle.Events.fontSize = "11px";
myStyle.Events.labelYOffset = 3;

myStyle.Events.context = {
  icon: function(feature) {
    var iconMap,
        iconPath,
        type = "single";

    iconMap = {
      ...
    }

    if(feature.attributes.count) {
      type = "clustered";
    }

    return iconMap[feature.attributes.name][type];
  },
  count: function(feature) {
    var labelText = "";

    if(feature.attributes.count) {
      labelText = feature.attributes.count;
    }

    return labelText;
  }
};

---

我怎样才能像那样在飞行中正确地应用该上下文？我不能使用典型的OpenLayers.Style（{}，{context:context}）；语法。

必须将

上下文

属性应用于

OpenLayers.Style

实例，如下所示：

var style = OpenLayers.Util.extend({}, OpenLayers.Feature.Vector.style["default"]);
style.pointRadius = "${radius}";
style.fillColor = '${colorFunction}';

var defaultStyle = new OpenLayers.Style(style, {
    context: {
        colorFunction: function(feature) {
            return colors[feature.attributes.temp];
        }
    }
});

我建议您使用（主题7样式）或查看源代码示例（第7章-使用样式图和功能的属性替换改进样式）

干杯