Method setOpacity

src/openlayers/overlay/HeatMap.js:142–154

* @function HeatMap.prototype.setOpacity * @description 设置图层的不透明度，取值范围：[0-1]。 * @param {number} opacity - 不透明度。

(opacity)

     * @param {number} opacity - 不透明度。
     */
    setOpacity(opacity) {
        if (opacity !== this.opacity) {
            this.opacity = opacity;
            var element = this.rootCanvas;
            CommonUtil.modifyDOMElement(element, null, null, null,
                null, null, null, opacity);

            if (this.map !== null) {
                // this.dispatchEvent({type: 'changelayer', value: {layer: this, property: "opacity"}});
                this.changed();
            }
        }
    }

    /**
     * @function HeatMap.prototype.updateHeatPoints