JavaScript ArcGIS SizeSlider用法及代码示例

AMD: require(["esri/widgets/smartMapping/SizeSlider"], (SizeSlider) => { /* code goes here */ });

ESM: import SizeSlider from "@arcgis/core/widgets/smartMapping/SizeSlider";

类： esri/widgets/smartMapping/SizeSlider

继承: SizeSlider > SmartMappingSliderBase > Widget > Accessor

自从：用于 JavaScript 4.12 的 ArcGIS API

SizeSlider 小部件旨在用于在可以使用 SizeVariable 渲染的任何层中创作和探索数据驱动的可视化。您至少必须设置小部件的最小、最大和停止属性。

有关此滑块上可用的可配置选项的摘要，请参见下图。

fromRendererResult 方法可用于根据 createContinuousRenderer 方法的结果方便地创建此滑块。

const sizeParams = {
  layer: layer,
  basemap: map.basemap,
  valueExpression: "( $feature.POP_POVERTY / $feature.TOTPOP_CY ) * 100",
  view: view
};

let rendererResult = null;

sizeRendererCreator
  .createContinuousRenderer(sizeParams)
  .then(function(response) {
    rendererResult = response;
    layer.renderer = response.renderer;

    return histogram({
      layer: layer,
      valueExpression: sizeParams.valueExpression,
      view: view,
      numBins: 70
    });
  })
   .then(function(histogramResult) {
     const sizeSlider = SizeSlider.fromRendererResult(rendererResult, histogramResult);
     sizeSlider.container = "slider";
   })
   .catch(function(error) {
     console.log("there was an error: ", error);
   });

此滑块应用于更新图层渲染器中的size visual variable。应用程序开发人员有责任在更新适当渲染器的大小变量时设置事件侦听器。

// when the user slides the handle(s), update the renderer
// with the updated size stops

sizeSlider.on(["thumb-change", "thumb-drag"], function() {
  const renderer = layer.renderer.clone();
  const sizeVariable = renderer.visualVariables[0];
  renderer.visualVariables = [ sizeSlider.updateVisualVariable(sizeVariable) ];
  layer.renderer = renderer;
});