MKMapViewiOS8中为什么不显示MKCircle?-WhyMKCircleisnotdisplayedonMKMapViewiOS8

3  

Rather than init, call the MKCircleRenderer method initWithCircle.

而不是init，调用MKCircleRenderer方法initWithCircle。

Obviously, make sure the delegate of the map view is set, that your code that adds the overlay and that instantiates the renderer is called at all, etc., but initWithCircle is the likely culprit.

显然，要确保map视图的委托已经设置，您添加叠加和实例化渲染器的代码已经被调用，等等，但是initWithCircle很可能是罪魁祸首。

7  

As per @Rob suggestion you need to init MKCircleRenderer using other method initWithCircle.

按照@Rob的建议，您需要使用其他方法initWithCircle初始化MKCircleRenderer。

- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id)overlay {
    MKCircleRenderer *circleRenderer = [[MKCircleRenderer alloc] initWithCircle:overlay];
    circleRenderer.fillColor = [UIColor greenColor];
    circleRenderer.alpha = 1.f;
    return circleRenderer;
}

Also make sure that fence distance is proper enough to visible the circle in map.

还要确保栅栏的距离足够在地图上显示圆形。

For example:

例如:

CLLocationDistance fenceDistance = 100000;
MKCircle *circle = [MKCircle circleWithCenterCoordinate:region.coordinate radius:fenceDistance];
[self.mapView addOverlay:circle];