ios - 谷歌地图半径缩放级别

Question

我有一张 map ，上面有一个自定义 UIView。我正在根据缩放级别计算圆的半径。

func getCenterCoordinate() -> CLLocationCoordinate2D {
    let centerPoint = self.mapView.center
    let centerCoordinate = self.mapView.projection.coordinate(for: centerPoint)
    return centerCoordinate
}

func getTopCenterCoordinate() -> CLLocationCoordinate2D {
    // to get coordinate from CGPoint of your map
    let topCenterCoor = self.mapView.convert(CGPoint(x:self.circleView.frame.size.width / 2.0, y:0), from: self.circleView)
    let point = self.mapView.projection.coordinate(for: topCenterCoor)
    return point
}

func getRadius() -> CLLocationDistance {

    let centerCoordinate = getCenterCoordinate()
    // init center location from center coordinate
    let centerLocation = CLLocation(latitude: centerCoordinate.latitude, longitude: centerCoordinate.longitude)
    let topCenterCoordinate = self.getTopCenterCoordinate()
    let topCenterLocation = CLLocation(latitude: topCenterCoordinate.latitude, longitude: topCenterCoordinate.longitude)

    let radius = CLLocationDistance(centerLocation.distance(from: topCenterLocation)) / 1000
    print(radius)
    return round(radius)
}

现在，我想根据给定的半径缩放 map ？我该怎么做？

Answer 1

在圆的周长上选取任意坐标，并将 map 的缩放或相机的缩放设置为该坐标的边界，当然还要添加一些填充。现在对于这个逻辑，如果您的 map 允许用户缩放，则每次您的 map 相机移动或重新居中时，您都必须重新计算。

您可以使用此方法:mapView.animateWithCameraUpdate(GMSCameraUpdate.fitBounds(bounds, withPadding: 50.0))

这里的 bounds 是一个 GMSCoordinateBounds 对象。

希望对你有帮助