Question

我使用的函数geocodeAddressString在swift 1.0中工作，但在swift2中没有。任何人都可以告诉我我的代码有什么问题以及如何解决这个问题？谢谢！

geocoder.geocodeAddressString(address, {(placemarks: [AnyObject], error: NSError) -> Void in  //Error: Missing argument for parameter 'completionHandler' in call

        if let placemark = placemarks?[0] as? CLPlacemark {
            let annotation = MKPointAnnotation()
            let location:CLLocationCoordinate2D = CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude)
            annotation.coordinate = location
            annotation.title = "\(StudentArray[student].firstName), \(StudentArray[student].lastName)"
            annotation.subtitle = "\(StudentArray[student].grade)"
            self.mapView.addAnnotation(annotation)
        }

    })

Answer 1

指定completionHandler参数名称：

geocoder.geocodeAddressString(address, completionHandler: { placemarks, error in
    if let placemark = placemarks.first as? CLPlacemark {
        let annotation = MKPointAnnotation()
        let location = CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude)
        annotation.coordinate = location
        annotation.title = "\(StudentArray[student].firstName), \(StudentArray[student].lastName)"
        annotation.subtitle = "\(StudentArray[student].grade)"
        self.mapView.addAnnotation(annotation)
    }
})

或者使用尾随闭包语法（参见 Swift编程语言的Closures章节中的尾随闭包部分），你可以在其中拉出闭包(和)并将其放在)：

之后

geocoder.geocodeAddressString(address) { placemarks, error in
    if let placemark = placemarks.first as? CLPlacemark {
        let annotation = MKPointAnnotation()
        let location = CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude)
        annotation.coordinate = location
        annotation.title = "\(StudentArray[student].firstName), \(StudentArray[student].lastName)"
        annotation.subtitle = "\(StudentArray[student].grade)"
        self.mapView.addAnnotation(annotation)
    }
}

Answer 2

在完成处理程序之前添加参数。

geocoder.geocodeAddressString(address, completionHandler: {(placemarks: [AnyObject], error: NSError) -> Void in  // Added argument for parameter 'completionHandler' in call

    if let placemark = placemarks?[0] as? CLPlacemark {
        let annotation = MKPointAnnotation()
        let location:CLLocationCoordinate2D = CLLocationCoordinate2DMake(placemark.location.coordinate.latitude, placemark.location.coordinate.longitude)
        annotation.coordinate = location
        annotation.title = "\(StudentArray[student].firstName), \(StudentArray[student].lastName)"
        annotation.subtitle = "\(StudentArray[student].grade)"
        self.mapView.addAnnotation(annotation)
    }

})

缺少参数＆＃39; completionHandler＆＃39;在电话中

2 个答案: