我想创建一个将几个MKShapes组合在一起的MKOverlay,但是我遇到了合成的MKOverlayRenderer问题。
我想避免将这些作为单独的MKOverlays和MKOverlayRenderers,因为a)这是很多文件而b)它们在概念上是相同的。
这就是我所拥有的。来自MyOverlay.h:
@property (nonatomic) CLLocationCoordinate2D coordinate;
@property (nonatomic, readonly) MKMapRect boundingMapRect;
@property (strong, nonatomic, readonly) MKCircle *circle;
@property (strong, nonatomic, readonly) MKCircle *editCircle;
@property (strong, nonatomic, readonly) MKPolyline *radiusLine;
来自MyOverlay.m:
- (id)initWithCoordinate:(CLLocationCoordinate2D)coordinate {
self = [super init];
if (self) {
_coordinate = coordinate;
_circle = [MKCircle circleWithCenterCoordinate:_coordinate radius:_radius];
_editCircle = [MKCircle circleWithCenterCoordinate:_coordinate radius:_radius * 0.1];
CLLocationCoordinate2D offset = [self translateCoord:_coordinate distanceLat:0.0 distanceLong:_radius];
CLLocationCoordinate2D coords[2];
coords[0] = _coordinate;
coords[1] = offset;
_radiusLine = [MKPolyline polylineWithCoordinates:coords count:2];
_boundingMapRect = MKMapRectUnion(MKMapRectUnion(_circle.boundingMapRect, _editCircle.boundingMapRect), _radiusLine.boundingMapRect);
}
return self;
}
来自MyOverlayRenderer.m:
@interface MyOverlayRenderer ()
@property (nonatomic, strong) MKCircleRenderer *circleRenderer;
@property (nonatomic, strong) MKCircleRenderer *editCircleRenderer;
@property (nonatomic, strong) MKPolylineRenderer *radiusLineRenderer;
@property (nonatomic) MKMapRect circleBoundingMapRect;
@property (nonatomic) MKMapRect editCircleBoundingMapRect;
@property (nonatomic) MKMapRect radiusLineBoundingMapRect;
@end
@implementation MyOverlayRenderer
- (instancetype)initWithMyOverlay:(MyOverlay *)overlay {
self = [super initWithOverlay: overlay];
if (self) {
_circleRenderer = [[MKCircleRenderer alloc] initWithCircle: overlay.circle];
_circleRenderer.lineWidth = 2.0;
_circleRenderer.strokeColor = overlay.color;
_circleBoundingMapRect = overlay.circle.boundingMapRect;
CGFloat red, green, blue, alpha;
[overlay.color getRed:&red green:&green blue:&blue alpha:&alpha];
_circleRenderer.fillColor = [UIColor colorWithRed:red green:green blue:blue alpha:alpha * 0.2];
_editCircleRenderer = [[MKCircleRenderer alloc] initWithCircle:overlay.editCircle];
_editCircleRenderer.fillColor = overlay.color;
_editCircleBoundingMapRect = overlay.editCircle.boundingMapRect;
_radiusLineRenderer = [[MKPolylineRenderer alloc] initWithPolyline:overlay.radiusLine];
_radiusLineRenderer.lineWidth = 1.5;
_radiusLineRenderer.strokeColor = overlay.color;
_radiusLineRenderer.lineDashPattern = @[@2.0, @2.0];
_radiusLineBoundingMapRect = overlay.radiusLine.boundingMapRect;
}
return self;
}
- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context {
double x = MKMapRectGetMidX(mapRect);
double y = MKMapRectGetMidY(mapRect);
CGContextSaveGState(context);
[_circleRenderer drawMapRect:_circleBoundingMapRect zoomScale:zoomScale inContext:context];
CGContextRestoreGState(context);
CGContextSaveGState(context);
CGContextMoveToPoint(context, x, y);
[_editCircleRenderer drawMapRect:_editCircleBoundingMapRect zoomScale:zoomScale inContext:context];
CGContextRestoreGState(context);
CGContextMoveToPoint(context, x, y);
[_radiusLineRenderer drawMapRect:_radiusLineBoundingMapRect zoomScale:zoomScale inContext:context];
}
结果很难看。 radiusLine应该来自圆的中心,而editCircle应该沿着圆的边缘。
我相信我的错误出现在drawMapRect:zoomScale:inContext:
方法中 - 这只是我在那里尝试的最新代码 - 但我不确定错误是什么......
答案 0 :(得分:1)
是的,问题发生在drawMapRect:zoomScale:inContext:
。在绘制复合材料之前,我必须将其转换为复合材料中每个元素的来源。这有效:
- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context {
CGPoint p;
CGContextSaveGState(context);
p = [self pointForMapPoint:_circleMapRect.origin];
CGContextTranslateCTM(context, p.x, p.y);
[_circleRenderer drawMapRect:_circleBoundingMapRect zoomScale:zoomScale inContext:context];
CGContextRestoreGState(context);
CGContextSaveGState(context);
p = [self pointForMapPoint:_editCircleBoundingMapRect.origin];
CGContextTranslateCTM(context, p.x, p.y);
[_editCircleRenderer drawMapRect:_editCircleBoundingMapRect zoomScale:zoomScale inContext:context];
CGContextRestoreGState(context);
CGContextSaveGState(context);
p = [self pointForMapPoint:_radiusLineBoundingMapRect.origin];
CGContextTranslateCTM(context, p.x, p.y);
[_radiusLineRenderer drawMapRect:_radiusLineBoundingMapRect zoomScale:zoomScale inContext:context];
CGContextRestoreGState(context);
}