Question

我想将MKMapPoint转换为NSValue。在Objective-C中，我可以使用以下语句来完成：

MKMapPoint point = MKMapPointForCoordinate(location.coordinate);
NSValue *pointValue = [NSValue value:&point withObjCType:@encode(MKMapPoint)];

我怎样才能在Swift中做到这一点？谢谢！

Answer 1

在Swift中不可能，但您仍然可以在ObjC中创建一个类别并在Swift项目中使用它

// NSValue+MKMapPoint.h
@interface NSValue (MKMapPoint)

+ (NSValue *)valueWithMKMapPoint:(MKMapPoint)mapPoint;
- (MKMapPoint)MKMapPointValue;

@end


// NSValue+MKMapPoint.m
@implementation NSValue (MKMapPoint)

+ (NSValue *)valueWithMKMapPoint:(MKMapPoint)mapPoint {
    return [NSValue value:&mapPoint withObjCType:@encode(MKMapPoint)];
}

- (MKMapPoint)MKMapPointValue {
    MKMapPoint mapPoint;
    [self getValue:&mapPoint];
    return mapPoint;
}

@end

Swift中的用法：

let mapValue = CGValue(MKMapPoint: <your map point>)
let mapPoint = mapValue.MKMapPointValue();

Answer 2

我认为狮子座的答案不再正确，我设法通过下面的代码将MKMapPoint数组转换为CGPoint数组：

let polygonView = MKPolygonRenderer(overlay: overlay)
let polyPoints = polygonView.polygon.points() //returns [MKMapPoint]
var arrOfCGPoints : [CGPoint] = []
for i in 0..<polygonView.polygon.pointCount {
    arrOfCGPoints.append(polygonView.point(for: polyPoints[i])) //converts to CGPoint
    }
print(arrOfCGPoints)
//prints [(10896.74671715498, 10527.267575368285), (10830.46552553773, 10503.901612073183), (10741.784851640463, 10480.270403653383), (10653.04738676548, 10456.62348484993), (10566.442882657051, 10409.803505435586)]

然后转到NSValue：

ler someCgPoint = arrOfCGPoints[0]
var pointObj = NSValue(CGPoint: someCgPoint)

Answer 3

可悲的是，这在Swift中是不可能的。

Answer 4

试试这个

        let mapPoint = MKMapPointForCoordinate(coordinate)

        let type = NSValue(MKCoordinate: coordinate).objCType // <- THIS IS IT

        let value = NSValue(bytes: unsafeAddressOf(mapPoint as! AnyObject), objCType: type);

在Swift中将MKMapPoint转换为NSValue

4 个答案: