我已将MKCircle作为MKOverlay添加到了我的MKMapView中。同时,我添加了一个UISlider来决定圆形的半径。不幸的是,在使用它时,它似乎有一些"延迟",不像我想要的那样平滑流畅。
示例: http://dl.dropbox.com/u/3077127/mkoverlayDelay.mov 以下是我的代码:
示例: http://dl.dropbox.com/u/3077127/mkoverlayDelay.mov 以下是我的代码:
- (void)addCircle
{
// draw the radius circle for the marker
double radius = 2000.0;
MKCircle *circle = [MKCircle circleWithCenterCoordinate:location radius:radius];
[circle setTitle:@"background"];
[mapView addOverlay:circle];
MKCircle *circleLine = [MKCircle circleWithCenterCoordinate:location radius:radius];
[circleLine setTitle:@"line"];
[mapView addOverlay:circleLine];
}
- (void)addCircleWithRadius:(double)radius
{
MKCircle *circle = [MKCircle circleWithCenterCoordinate:location radius:radius];
[circle setTitle:@"background"];
[mapView addOverlay:circle];
MKCircle *circleLine = [MKCircle circleWithCenterCoordinate:location radius:radius];
[circleLine setTitle:@"line"];
[mapView addOverlay:circleLine];
}
- (void)sliderChanged:(UISlider*)sender
{
[mapView removeOverlays:[mapView overlays]];
double radius = (sender.value * 100);
[self addCircleWithRadius:radius];
}
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay{
MKCircle *circle = overlay;
MKCircleView *circleView = [[[MKCircleView alloc] initWithCircle:overlay] autorelease];
if ([circle.title isEqualToString:@"background"])
{
circleView.fillColor = UIColorFromRGB(0x598DD3);
circleView.alpha = 0.25;
}
else
{
circleView.strokeColor = UIColorFromRGB(0x5C8AC7);
circleView.lineWidth = 2.0;
}
return circleView;
}
有人有关于如何使这个更加顺畅的建议吗?
最好的问候,
保罗·皮伦