放大或缩小时使半径恒定

Question

我是openlayers的新手，我试图弄清楚在放大或缩小创建要素的地图时如何使圆保持不变。到目前为止，这是我尝试过的。

<div *ngFor="let l of  line">
        <aol-feature *ngFor="let s of l?.segments" [id]="s.fromId">
          <aol-geometry-point>
            <aol-coordinate [x]="s?.from?.position?.longitude "     [y]="s?.from?.position?.latitude " [srid]="'EPSG:4326'"></aol-coordinate>
          </aol-geometry-point>
          <aol-style>
            <aol-style-circle [radius]="20" > //maybe here I'm doing wrong?
              <aol-style-stroke [color]="'black'"></aol-style-stroke>
              <aol-style-fill [color]="'white'"></aol-style-fill>
            </aol-style-circle>
            <aol-style-text [text]="s.from.name">
              <aol-style-fill [color]="'#black'"></aol-style-fill>
            </aol-style-text>
          </aol-style>
        </aol-feature>
  </div>