convert cgcs2000(4528, 4549, 4490) polygon shp or txt to CGCS_2000(EPSG:4490) geojson 代码写得很烂，凑活用吧，后面有空再重构

For node.js

npm install --save cgcsfile2json

import file2coor from 'cgcsfile2json'

let txtFile = getFile('test.txt');
let coors = file2coor.getCoordinates();
// coors: [4528, 4549, 4490];
// coorsCh: ['大地2000 有带号直角坐标系', '大地2000 无带号直角坐标系', '大地2000经纬度坐标系']
// txt's coordinate defalut is '大地2000 有带号直角坐标系'
let data = file2coor.convertFile(txtFile, 'txt'); 

let shpFile = getFile('test.shp');
let data2 = file2coor.convertFile(shpFile, 'shp', coors[2]); 

[4528, 4549, 4490]

convert .shp or .txt file to geojson

check if the geojson data is out of bounds when 'order' value is true, representes the point's coordinates is [lat, lon], otherwise defalut is [lon, lat]

defalut boundary is:

{ // 杭州范围
  xMin: 118.1217,
  xMax: 120.7753,
  yMin: 29.1304,
  yMax: 30.6191
}

judge the file(shp or txt)'s coordinates, txt file is 4528('大地2000 有带号直角坐标系').

The coordinate system of SHP file will be judged by whether the converted data exceeds the set boundary

parse the shp file to geojson

parsingShape(file).then(res => {
  console.log(res);
})

convert the data to CGCS_2000(EPSG:4490) geojson when precise param is false, use the offline algorithm, which can only be accurate to the seven decimal place. defalut chose the online algorithm provided by arcgis server.

convert cscs2000(XYZ) point to cscs2000(BLH)