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想象一下，我有 6 个圆圈。我的计时器在开始时调用前 2 个圆圈并将它们覆盖在地图视图上。然后在 2 秒后，它会调用其他圈子并将它们添加到地图视图中。我的问题是如何删除以前的叠加层。我想看到例如雷达地图的平滑过渡。

简而言之，它想删除以前的叠加层并添加新的叠加层而不闪烁！非常感谢提前！！

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
@synthesize mapView;
@synthesize timer;
@synthesize circle1,circle2,circle3,circle4,circle5,circle6;



- (void)viewDidLoad
{
    [super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
    CLLocationCoordinate2D zoomLocation1;

zoomLocation1.latitude=29.830071;
zoomLocation1.longitude=-95.319099;
circle1 = [MKCircle circleWithCenterCoordinate:zoomLocation1 radius:15000];
circle1.title=@"first level";

CLLocationCoordinate2D zoomLocation2;
zoomLocation2.latitude=29.830071;
zoomLocation2.longitude=-95.319099;
circle2 = [MKCircle circleWithCenterCoordinate:zoomLocation2 radius:4000];
circle2.title=@"first level";

CLLocationCoordinate2D zoomLocation3;
zoomLocation3.latitude=29.830071;
zoomLocation3.longitude=-95.319099;
circle3 = [MKCircle circleWithCenterCoordinate:zoomLocation3 radius:6000];
circle3.title=@"second level";

CLLocationCoordinate2D zoomLocation4;
zoomLocation4.latitude=29.830071;
zoomLocation4.longitude=-95.319099;
circle4 = [MKCircle circleWithCenterCoordinate:zoomLocation4 radius:18000];
circle4.title=@"second level";

CLLocationCoordinate2D zoomLocation5;
zoomLocation5.latitude=29.830071;
zoomLocation5.longitude=-95.319099;
circle5 = [MKCircle circleWithCenterCoordinate:zoomLocation5 radius:1000];
circle5.title=@"third level";

CLLocationCoordinate2D zoomLocation6;
zoomLocation6.latitude=29.830071;
zoomLocation6.longitude=-95.319099;
circle6 = [MKCircle circleWithCenterCoordinate:zoomLocation6 radius:13000];
circle6.title=@"third level";


    MKCoordinateRegion viewRegion=MKCoordinateRegionMakeWithDistance(zoomLocation1, 60*1609, 60*1609);

MKCoordinateRegion adjustedRegion=[mapView regionThatFits:viewRegion];

[mapView setRegion:adjustedRegion animated:YES];
mapView.mapType=MKMapTypeStandard;
[mapView setDelegate:(id)self];
i=0;
}

- (void)viewDidUnload
{
[self setMapView:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}

- (BOOL)shouldAutorotateToInterfaceOrientation:    (UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

- (IBAction)drawButton:(id)sender {
timer = [NSTimer scheduledTimerWithTimeInterval:(2.0) target:self     selector:@selector(addingOverlay) userInfo:nil repeats:YES];

}


- (void)addingOverlay {

i=i+1;    
switch(i%3)
{
    case 1:
        [mapView removeOverlays: [mapView overlays]];
        [mapView addOverlay:circle1];
        [mapView addOverlay:circle2];
        break;
    case 2:
        [mapView removeOverlays: [mapView overlays]];
        [mapView addOverlay:circle3];
        [mapView addOverlay:circle4];
        break;
    case 3:
        [mapView removeOverlays: [mapView overlays]];
        [mapView addOverlay:circle5];
        [mapView addOverlay:circle6];
        break;

}


}

-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay> )overlay
{
MKCircleView *circleView = [[MKCircleView alloc] initWithOverlay:overlay];
if ([overlay.title isEqualToString:@"first level"]) 
{
circleView.strokeColor = [UIColor redColor];
circleView.lineWidth = 2;
circleView.fillColor=[UIColor yellowColor];
}
else if([overlay.title isEqualToString:@"second level"])
{
circleView.strokeColor = [UIColor whiteColor];
circleView.lineWidth = 2;
circleView.fillColor=[UIColor blackColor];
}
else{
circleView.strokeColor = [UIColor greenColor];
circleView.lineWidth = 2;
circleView.fillColor=[UIColor redColor];


}

return circleView;
}




@end
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1 回答 1

1

我刚刚发布了一个类似问题的答案。

它有一个函数，我使用 ( drawRangeRings) 绘制两个圆圈。在我的示例中，两个圆的中心坐标相同，但半径值和颜色不同。如果需要，您可以轻松更改代码以对每个圆使用不同的中心坐标。

基本上，我drawRangeRings在中心坐标发生变化时调用，它会删除原来的两个圆，并在不同的位置绘制两个新圆。

如果这不是您所需要的，请告诉我。

当我在我的应用程序中使用它时，我没有看到任何闪烁。

于 2012-09-23T03:52:03.047 回答