iOS - MKOverlayView 自定义视图矩形填充有效,但线条绘制无效
地图叠加新手,但这是一个非常奇怪的问题。
我将 mapView.visibleMapRect 传递给我的覆盖实现,并将其作为boundingMapRect返回,这目前很好 - 只是尝试在整个地图矩形上画一条线。
我的drawMapRect 被调用,在下面的代码中 - 绘制了部分透明的绿色矩形,但没有绘制线条。我已经验证了 uiview 子类的drawRect中的线条绘制代码,所以我知道它画了一些东西:-)
我确信我一定错过了一些简单的东西,但我看不到它:-)让
我困惑的东西关闭的是,当转换为 CGRect 时,visibleMapRect 有非常奇怪的坐标 - 它们对我来说根本不像屏幕坐标 - 这对我来说似乎是问题的根源。
任何帮助将不胜感激:
drawMapRect 被多次调用,我在下面附上输出。
谢谢, Bob
ViewController 设置代码:
CLLocationCoordinate2D center;
center.latitude = 29.46;
center.longitude = -98.30;
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta = 0.2;
span.longitudeDelta = 0.2;
region.center = center;
region.span = span;
self.mapView.region = region;
MyOverlay *myoverlay = [[MyOverlay alloc] initWithCoordinate: center andBoundingRect: self.mapView.visibleMapRect];
[self.mapView addOverlay:myoverlay];
MyOverlay 代码:
@implementation MyOverlay
@synthesize coordinate;
@synthesize boundingMapRect;
- (id) initWithCoordinate: (CLLocationCoordinate2D) coord andBoundingRect: (MKMapRect) bRect {
if ((self = [super init])) {
//customize here
coordinate = coord;
boundingMapRect = bRect;
}
return self;
}
MyOverlayView 绘图代码
- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context {
CGRect theRect = [self rectForMapRect:mapRect];
NSLog(@"in drawMapRect ...theRect is %f, %f, size of %f x %f", theRect.origin.x, theRect.origin.y, theRect.size.width, theRect.size.height);
CGContextSetAlpha(context, 1.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, theRect.origin.x, theRect.origin.y);
CGContextAddLineToPoint(context, theRect.size.width, theRect.size.width);
CGContextSetAlpha(context, .25);
CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);
CGContextFillRect(context, theRect);
}
输出
2011-05-16 11:25:18.037 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 61440.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.038 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.042 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 323584.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.044 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.046 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.048 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 61440.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.052 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.054 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 323584.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.056 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.057 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.059 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 61440.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.061 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 61440.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.063 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.064 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 323584.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.066 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.068 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.070 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.072 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 585728.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.074 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.075 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -462848.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.082 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 61440.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.082 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.085 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 61440.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.087 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -462848.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.089 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.099 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.102 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.106 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.109 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.111 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.116 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.119 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 585728.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.124 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -462848.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.126 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, -486400.000000, size of 262144.000000 x 262144.000000
New to Map Overlays, but this is a really weird problem.
I pass in the mapView.visibleMapRect to my overlay implementation and return that as the boundingMapRect, which is fine for now - just trying to draw a line on the whole map rect.
My drawMapRect is getting called, and in the following code - the partially transparent green rectangle is drawn, but the lines are not. I've verified the line drawing code in drawRect of a uiview subclass, so I know it draws something :-)
I'm sure I must be missing something easy, but I can't see it :-)
The thing that throws me off is that the visibleMapRect, when converted to a CGRect has very strange coordinates - they don't look like screen coordinates to me at all - which seems like the source of the problem to me.
Any help would be greatly appreciated:
The drawMapRect is called multiple times, i'm attaching the output below.
Thanks,
Bob
ViewController setup code:
CLLocationCoordinate2D center;
center.latitude = 29.46;
center.longitude = -98.30;
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta = 0.2;
span.longitudeDelta = 0.2;
region.center = center;
region.span = span;
self.mapView.region = region;
MyOverlay *myoverlay = [[MyOverlay alloc] initWithCoordinate: center andBoundingRect: self.mapView.visibleMapRect];
[self.mapView addOverlay:myoverlay];
MyOverlay code:
@implementation MyOverlay
@synthesize coordinate;
@synthesize boundingMapRect;
- (id) initWithCoordinate: (CLLocationCoordinate2D) coord andBoundingRect: (MKMapRect) bRect {
if ((self = [super init])) {
//customize here
coordinate = coord;
boundingMapRect = bRect;
}
return self;
}
MyOverlayView drawing code
- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context {
CGRect theRect = [self rectForMapRect:mapRect];
NSLog(@"in drawMapRect ...theRect is %f, %f, size of %f x %f", theRect.origin.x, theRect.origin.y, theRect.size.width, theRect.size.height);
CGContextSetAlpha(context, 1.0);
CGContextSetStrokeColorWithColor(context, [UIColor blueColor].CGColor);
CGContextMoveToPoint(context, theRect.origin.x, theRect.origin.y);
CGContextAddLineToPoint(context, theRect.size.width, theRect.size.width);
CGContextSetAlpha(context, .25);
CGContextSetFillColorWithColor(context, [UIColor greenColor].CGColor);
CGContextFillRect(context, theRect);
}
Output
2011-05-16 11:25:18.037 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 61440.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.038 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.042 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 323584.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.044 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.046 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.048 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 61440.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.052 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.054 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 323584.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.056 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.057 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.059 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 61440.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.061 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 61440.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.063 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.064 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 323584.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.066 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.068 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.070 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.072 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 585728.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.074 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.075 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -462848.000000, 37888.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.082 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 61440.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.082 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.085 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 61440.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.087 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -462848.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.089 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, -224256.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.099 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.102 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, 300032.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.106 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 323584.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.109 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -200704.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.111 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -200704.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.116 coolOverlayTest[71661:760b] in drawMapRect ...theRect is 585728.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.119 coolOverlayTest[71661:7903] in drawMapRect ...theRect is 585728.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.124 coolOverlayTest[71661:7903] in drawMapRect ...theRect is -462848.000000, -486400.000000, size of 262144.000000 x 262144.000000
2011-05-16 11:25:18.126 coolOverlayTest[71661:760b] in drawMapRect ...theRect is -462848.000000, -486400.000000, size of 262144.000000 x 262144.000000
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评论(3)
需要考虑的一件事是,出于性能原因,在多个线程上调用
drawMapRect:
。这解释了为什么您会看到drawMapRect:
被多次调用。此外,此方法的mapRect
输入不一定等于可见的mapView.visibleMapRect
。事实上,mapRect
通常是mapView.visibleMapRect
的一小部分,不同的线程渲染mapView.visibleMapRect
的不同区域。因此,仅仅因为一个点包含在mapView.visibleMapRect
内,并不意味着它包含在传递给所有对drawMapRect
结果调用的mapRect
内。代码>.One thing to consider is that for performance reasons,
drawMapRect:
is called on multiple threads. This explains why you seedrawMapRect:
getting called multiple times. Additionally themapRect
input to this method is NOT necessarily equal to the visiblemapView.visibleMapRect
. In factmapRect
is usually a small section ofmapView.visibleMapRect
and different threads render different regions ofmapView.visibleMapRect
. Thus just because a point is contained insidemapView.visibleMapRect
it does not mean that it is contained within themapRect
passed to all of the resulting calls todrawMapRect
.您在调用 CGContextAddLineToPoint 时坐标错误。你有:
但它应该是:
至少如果你希望在你的矩形上画一条对角线。
另外,正如 Ludvik Polak 上面提到的,您可能还需要使用以下方法设置线宽:
You have the wrong coordinates in your call to CGContextAddLineToPoint. You have:
but it should be:
At least if you are hoping to draw a line diagonally across your rectangle.
Also as Ludvik Polak mentioned above, you probably also need to set the line width using something like:
当同一张地图上加载另一个 MKTileOverlay 时,我遇到了这个问题。它将导致自定义覆盖层刷新,直到另一个覆盖层绘制图块为止,这在网络负载的情况下可能需要几秒钟的时间。
I have come across this when there is another MKTileOverlay loading on the same map. It will cause the custom overlay to refresh until a tile is drawn by the other overlay, which may take several seconds in case of network load.