MKOverlay有时会消失

Question

我在我的地图中有两个覆盖选项:一个MKCircleOverlay和一个MKPolygonOverlay.The首先是可变半径，通过UISlider.The控制最后是可自定义的取决于corners.If的数量和位置我改变非常快的圆的半径(减少UISlider的值)有时我的覆盖消失(圆)和之后，多边形不能再被绘制(当然，圆也).No崩溃的app.What可能是？

下面是我使用的一些代码：

- (IBAction) addCircle:(id)sender
{
slider.hidden = NO;
slider.transform = CGAffineTransformMakeRotation(M_PI*(-0.5));

_longPressRecognizer= [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
_longPressRecognizer.minimumPressDuration = 1.0; 

[mapview addGestureRecognizer:_longPressRecognizer];
[_longPressRecognizer release];
}

- (void)handleLongPress:(UIGestureRecognizer *)gestureRecognizer
{
if (gestureRecognizer.state != UIGestureRecognizerStateBegan)
    return;
CGPoint touchPoint = [gestureRecognizer locationInView:mapview];    
CLLocationCoordinate2D touchMapCoordinate = [mapview convertPoint:touchPoint toCoordinateFromView:mapview];

MKPointAnnotation *pa = [[MKPointAnnotation alloc] init];
pa.coordinate = touchMapCoordinate;
pa.title = @"Circle Based Search";

[mapview addAnnotation:pa];
[pa release];

tmC = touchMapCoordinate;
double radius = 1000.0;

self.circleOverlay = [MKCircle circleWithCenterCoordinate:tmC radius:radius];
[mapview removeOverlays:[mapview overlays]];
[mapview addOverlay:circleOverlay];
[mapview removeAnnotations:[mapview annotations]];
}


-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id)overlay 
{
if ([overlay isKindOfClass:[MKCircle class]])
{
    MKCircleView* circleView = [[MKCircleView alloc] initWithOverlay:overlay] ;
    circleView.fillColor = [UIColor blueColor];
    circleView.strokeColor = [UIColor blueColor];
    circleView.lineWidth = 5.0;
    circleView.alpha = 0.20;
        return circleView;
}
else
    if ([overlay isKindOfClass:[MKPolygon class]])
{
    MKPolygonView *polygonView = [[MKPolygonView alloc] initWithOverlay:overlay ];
    polygonView.fillColor = [UIColor blueColor];
    polygonView.strokeColor = [UIColor blueColor];
    polygonView.lineWidth = 5.0;
    polygonView.alpha = 0.20;
    return polygonView;
}
return [kml viewForOverlay:overlay];
}

- (void)addCircleWithRadius:(double)radius
{
self.circleOverlay = [MKCircle circleWithCenterCoordinate:tmC radius:radius];
[mapview removeOverlays:[mapview overlays]];
[mapview addOverlay:circleOverlay];
[mapview removeAnnotations:[mapview annotations]];
}

- (IBAction)sliderChanged:(UISlider *)sender
{
    double radius = (sender.value);
[self addCircleWithRadius:radius];
[mapview removeAnnotations:[mapview annotations]];
}

Answer 1

问题出在UISlider，在笔尖上，在Values solved.It property Continuous I checked.After下的滑块检查器中，我取消选中它，问题就解决了。