放大缩小在Expo的Mapview中不起作用

Question

我的地图运行良好，但是当我放大地图时会产生振动效果，并且不会发生缩放。下面是我的代码：

this.showDirection(this.props.pickUpAddress, this.props.destAddress);
      return (
        <MapView.Polyline
          coordinates={this.state.coords}
          strokeWidth={2}
          strokeColor={commonColor.brandPrimary}
        />
      );



async showDirection(startLoc, destinationLoc) {
    try {
      let resp = await fetch(
        `https://maps.googleapis.com/maps/api/directions/json?origin=${startLoc}&destination=${destinationLoc}`
      );
      let respJson = await resp.json();
      let points = Polyline.decode(respJson.routes[0].overview_polyline.points);
      let distance = respJson.routes[0].legs
        .map(leg => leg.distance.value)
        .reduce((a, c) => a + c);
      let coords = points.map((point, index) => {
        /*console.log("lat and long are");
        console.log(point);*/
        return {
          latitude: point[0],
          longitude: point[1]
        };
      });
      this.setState({ coords: coords });
    } catch (error) {
      console.log(error);
    }
  }

谢谢。