OpenLayers 5 获取范围坐标答案

【问题标题】：OpenLayers 5 get extent coordinatesOpenLayers 5 获取范围坐标
【发布时间】：2019-07-16 14:34:21
【问题描述】：

我正在尝试从 OpenLayers 5 中的范围创建 MultiPolygon

我通过dragBox的地图交互来获取范围

let extent = selectBox.getGeometry().getExtent();
    myService.select(extent);

select(extent){
let topLeft = extent.getTopLeft();
let topRight = extent.getTopRight();
let bottomLeft = extent.getBottomLeft();
let bottomRight = extent.getBottomRight();
};

getter 似乎不起作用，我收到一条错误消息，例如：“extent.getTopLeft 不是函数”

感谢任何帮助

【问题讨论】：

标签： openlayers openlayers-5 angular-openlayers

【解决方案1】：

使用类似的东西

import * as olExtent from 'ol/extent';

let extent = selectBox.getGeometry().getExtent();
    myService.select(extent);

select(extent){
let topLeft = olExtent.getTopLeft(extent);
let topRight = olExtent.getTopRight(extent);
let bottomLeft = olExtent.getBottomLeft(extent);
let bottomRight = olExtent.getBottomRight(extent);
};

【讨论】：

【解决方案2】：

我的解决方案...

import { getBottomLeft, getBottomRight, getTopLeft, getTopRight } from 'ol/extent';

然后在您的事件/功能中使用所选功能：

const bottomLeft = getBottomLeft(feature.getGeometry().getExtent());
const bottomRight = getBottomRight(feature.getGeometry().getExtent());
const topLeft = getTopLeft(feature.getGeometry().getExtent());
const topRight = getTopRight(feature.getGeometry().getExtent());
console.log(`bottomLeft = ${ bottomLeft }, bottomRight = ${ bottomRight }, topLeft = ${ topLeft }, topRight = ${ topRight }`);

输出：

bottomLeft = 961504.4946941067,5919028.71679848, bottomRight = 961504.4946941067,5919028.71679848, topLeft = 961504.4946941067,5919028.71679848, topRight = 961504.4946941067,5919028.71679848

可以参考官方文档：https://openlayers.org/en/latest/apidoc/module-ol_extent.html

【讨论】：