Question

编译代码时，我在这一行上收到错误：我使用的是Swift 4.0

    } as! MKDirectionsHandler)

错误说：Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)

有人可以帮忙。代码如下：

 @objc func getDirections(sender: AnyObject){
       if let selectedPin = selectedPin {
            let mapItem = MKMapItem(placemark: selectedPin)
            //let launchOptions = [MKLaunchOptionsDirectionsModeKey : MKLaunchOptionsDirectionsModeDriving]
            //mapItem.openInMaps(launchOptions: launchOptions)

            let request = MKDirectionsRequest()
            request.source = MKMapItem.forCurrentLocation()

            request.destination = destination
            request.requestsAlternateRoutes = false

            let directions = MKDirections(request: request)

        directions.calculate(completionHandler: {(response: MKDirectionsResponse!, error: NSError!) in

            if error != nil {
                print("Error \(error)")

            } else {

                //self.displayRout(response)

                var overlays = self.mapView.overlays

                for route in response.routes {

                    self.mapView.add(route.polyline, level: MKOverlayLevel.aboveRoads)

                    for next in route.steps {
                        print(next.instructions)
                    }
                }
            }


            } as! MKDirectionsHandler)
        }

    //***********
    func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer!
    {
        let draw = MKPolylineRenderer(overlay: overlay)
        draw.strokeColor = UIColor.purple
        draw.lineWidth = 3.0
        return draw
    }
    }

这也是我得到的错误：

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)
  * frame #0: 0x00000001039d5c74 Map`ViewController.getDirections(sender=0x00007fff5c22e610, self=0x00007ff278553bc0) at ViewController.swift:117
    frame #1: 0x00000001039d6828 Map`@objc ViewController.getDirections(sender:) at ViewController.swift:0
    frame #2: 0x00000001050d1275 UIKit`-[UIApplication sendAction:to:from:forEvent:] + 83
    frame #3: 0x000000010524e4a2 UIKit`-[UIControl sendAction:to:forEvent:] + 67
    frame #4: 0x000000010524e7bf UIKit`-[UIControl _sendActionsForEvents:withEvent:] + 450
    frame #5: 0x000000010524d6ec UIKit`-[UIControl touchesEnded:withEvent:] + 618
    frame #6: 0x00000001056ba1a5 UIKit`_UIGestureEnvironmentSortAndSendDelayedTouches + 5560
    frame #7: 0x00000001056b4045 UIKit`_UIGestureEnvironmentUpdate + 1506
    frame #8: 0x000000010a912d37 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    frame #9: 0x000000010a912c8e CoreFoundation`__CFRunLoopDoObservers + 430
    frame #10: 0x000000010a8f7254 CoreFoundation`__CFRunLoopRun + 1572
    frame #11: 0x000000010a8f69b9 CoreFoundation`CFRunLoopRunSpecific + 409
    frame #12: 0x0000000107e309c6 GraphicsServices`GSEventRunModal + 62
    frame #13: 0x00000001050cf5e8 UIKit`UIApplicationMain + 159
    frame #14: 0x00000001039dac77 Map`main at AppDelegate.swift:12
    frame #15: 0x000000010d79cd81 libdyld.dylib`start + 1
    frame #16: 0x000000010d79cd81 libdyld.dylib`start + 1

Answer 1

您的代码中存在多个语法问题。

更改此行：

    directions.calculate(completionHandler: {(response: MKDirectionsResponse!, error: NSError!) in

为：

    directions.calculate(completionHandler: {(response, error) in

请注意error是Error，而不是NSError。

然后摆脱as! MKDirectionsHandler。没有理由投出完成处理程序。

    directions.calculate(completionHandler: { (response, error) in
        if error != nil {
            print("Error \(error)")
        } else {
            //self.displayRout(response)

            var overlays = self.mapView.overlays

            for route in response.routes {
                self.mapView.add(route.polyline, level: MKOverlayLevel.aboveRoads)

                for next in route.steps {
                    print(next.instructions)
                }
            }
        }
    })

单击对象时出错

1 个答案: