cesium 图层构建的那些事 （十七）

根据基础聚合类，我们构建geojosn序列化的聚合使用类

首先是参数定义

• interface ClassBreak {
• minValue: number,
• maxValue: number,
• symbol: any
• }
• interface UniqueValue {
• value: number,
• symbol: any
• }
•  
• export interface PRenderer {
• type: "simple"|"uniqueValue"|"classBreaks",
• field?: string,//simple不需要该参数
• symbol: any,
• classBreakInfos?: Array<ClassBreak>,
• uniqueValueInfos?:Array<UniqueValue>
• }

renderer设置
```javascript

import {PRenderer} from "./PRenderer";
import {ColorUtil} from "../utils/ColorUtil";

export class Renderer {
type = "Renderer";
private renderer: PRenderer;

• constructor(renderer: PRenderer) {
• this.renderer = renderer;
• }
•  
• /**
• * 获得symbol
• * @param attributes 属性
• * @param {boolean} isEntity 是否是Entity解析
• * @returns {any} symbol
• */
• public getSymbol(attributes: any, isEntity = false): any {
• const {type, field, symbol, uniqueValueInfos, classBreakInfos} = this.renderer;
• if (type === "simple") {
• if (!symbol) {
• throw new Error("缺少属性symbol");
• }
• return symbol;
• }
• let value = attributes[field || ""];
• if (isEntity) {
• value = value?._value
• }
• if (type === "uniqueValue") {
• if (!uniqueValueInfos) {
• throw new Error("缺少属性uniqueValueInfos");
• }
• for (const item of uniqueValueInfos) {
• if (item.value == value) {
• return item.symbol;
• }
• }
• }
• if (type === "classBreaks") {
• if (!classBreakInfos) {
• throw new Error("缺少属性classBreakInfos");
• }
• for (const item of classBreakInfos) {
• if (value >= item.minValue && value < item.maxValue) {
• return item.symbol;
• }
• }
• }
• return symbol;
• }
•  
•  
• public setEntitySymbol(entity: any, attributes: any) {
• const symbol = this.getSymbol(attributes, true);
• Renderer.setEntityProperties(entity, attributes, symbol);
• }
•  
•  
• public static setEntityProperties(obj: any, attributes: any, properties: any) {
• for (const key in properties) {
• const value = properties[key];
• if (Object.prototype.toString.call(value) == "[object Object]") {
• if (value instanceof Cesium.Color) {
• obj[key] = value
• } else if (value instanceof Cesium.LabelGraphics) {
• const v = value.clone();
• v.text = v.text._value.replace(/\${(\w+)+}/g, function (match, key) {
• return attributes[key]._value;
• });

 更多参考 https://xiaozhuanlan.com/topic/4596712380