React uses the turf plug-in to determine whether the point is within the surface (including points on the boundary of the surface, which cannot be judged by openlayers)

You need to download the turf plugin in advance, command: npm install @turf/turf
use:

import * as turf from '@turf/turf';

Judging whether the point is in the plane: (lonlatValid() is just a verification method written by myself, which can be ignored)

const piontisin = (rtkobj: any) => {
    
    
    if (lonlatValid(rtkobj.orderpoint_x) && lonlatValid(rtkobj.orderpoint_y) == true) {
    
    
      //判断点是否在面内
      let point_arr = turf.point(
        transform(
          [Number(rtkobj.orderpoint_x), Number(rtkobj.orderpoint_y)],
          'EPSG:4326',
          'EPSG:3857'
        )
      );
      let poly = turf.polygon([
        [
          transform([Number(rtkobj.p1_x), Number(rtkobj.p1_y)], 'EPSG:4326', 'EPSG:3857'),
          transform([Number(rtkobj.p2_x), Number(rtkobj.p2_y)], 'EPSG:4326', 'EPSG:3857'),
          transform([Number(rtkobj.p3_x), Number(rtkobj.p3_y)], 'EPSG:4326', 'EPSG:3857'),
          transform([Number(rtkobj.p4_x), Number(rtkobj.p4_y)], 'EPSG:4326', 'EPSG:3857'),
          transform([Number(rtkobj.p1_x), Number(rtkobj.p1_y)], 'EPSG:4326', 'EPSG:3857')
        ]
      ]);
      let isin = turf.booleanPointInPolygon(point_arr, poly);
      if (isin == false) {
    
    
        message.error('点不位于面内！');
      }
    }
  };