objective-c - MKMapPoint 不可转换为 Void 错误

Question

我正在尝试从坐标列表中在 MKMapView 上绘制路径，但出现两个错误。
这是代码（错误行有注释）：

var routes = [CoordVO]();
        routes.append(pn)
        routes.appe...

        var a = UInt(sizeof(CLLocationCoordinate2D)) * UInt(routes.count)
        var pointArr = malloc(a)

        for var idx = 0; idx < routes.count; idx++ {

            var obj = routes[idx]

            var workingCoordinate:CLLocationCoordinate2D!
            workingCoordinate.latitude=obj.lat
            workingCoordinate.longitude=obj.lng

            var point = MKMapPointForCoordinate(workingCoordinate)
            pointArr[idx] = point; // MKMapPoint is not convertible to Void

        }

        var routeLine = MKPolyline(points: pointArr, count: routes.count) // Void is not identical to MKMapPoint

        self.mapView.addOverlay(routeLine)

        free(pointArr);

Answer 1

看MKPolylineinit方法的定义：

init!(points points: UnsafeMutablePointer<MKMapPoint>, count count: Int)

它需要一个UnsafeMutablePointer<MKMapPoint>，但malloc你创建一个UnsafeMutablePointer<Void>，这会导致问题。