我试图找出MKMapRect的大小(即iPhone的320x568点)。将MKMapRect转换为CGRect
有没有类似的东西转换坐标点?即
[self.mapView convertCoordinate:coordinate1 toPointToView:self.view];
我试图找出MKMapRect的大小(即iPhone的320x568点)。将MKMapRect转换为CGRect
有没有类似的东西转换坐标点?即
[self.mapView convertCoordinate:coordinate1 toPointToView:self.view];
地图视图具有convertRegion:toRectToView:
方法,该方法需要一个MKCoordinateRegion
并将其转换为CGRect
相对于指定视图。
如果您有MKMapRect
,请先使用MKCoordinateRegionForMapRect
函数将其转换为MKCoordinateRegion
,然后再调用convertRegion:toRectToView:
。
实施例:
MKCoordinateRegion mkcr = MKCoordinateRegionForMapRect(someMKMapRect);
CGRect cgr = [mapView convertRegion:mkcr toRectToView:self.view];
记住的是,虽然MKMapRect
一段固定的区域将不会作为地图改变被缩放或平移,相应CGRect
将在其origin
和size
变化。
也许作为一个实际的例子...我用这个代码在屏幕上添加一个叠加到地图上,然后检查是否需要更新屏幕的哪一部分。
此方法是MKOverlay类的一部分。我的UIViewController被命名为“MyWaysViewController”,并在屏幕上的地图上被称为“MapOnScreen”(只是为了了解代码)
它的斯威夫特3/IOS 10码
/**
-----------------------------------------------------------------------------------------------
adds the overlay to the map and sets "setNeedsDisplay()" for the visible part of the overlay
-----------------------------------------------------------------------------------------------
- Parameters:
- Returns: nothing
*/
func switchOverlayON() {
DispatchQueue.main.async(execute: {
// add the new overlay
// if the ViewController is already initialised
if MyWaysViewController != nil {
// add the overlay
MyWaysViewController!.MapOnScreen.add(self)
// as we are good citizens on that device, we check if and for what region we setNeedsDisplay()
// get the intersection of the overlay and the visible region of the map
let visibleRectOfOverlayMK = MKMapRectIntersection(
self.boundingMapRect,
MyWaysViewController!.MapOnScreen.visibleMapRect
)
// check if it is null (no intersection -> not visible at the moment)
if MKMapRectIsNull(visibleRectOfOverlayMK) == false {
// It is not null, so at least parts are visible, now a two steps aproach to
// convert MKMapRect to cgRect. first step: get a coordinate region
let visibleRectCoordinateRegion = MKCoordinateRegionForMapRect(visibleRectOfOverlayMK)
// second step, convert the region to a cgRect
let visibleRectOfOverlayCG = MyWaysViewController!.MapOnScreen.convertRegion(visibleRectCoordinateRegion, toRectTo: MyWaysViewController!.MapOnScreen)
// ask to refresh that cgRect
MyWaysViewController!.MapOnScreen.setNeedsDisplay(visibleRectOfOverlayCG)
}
}
})
}