Swift3 为UISegmentedControl Swift 3分配目标

我有一个

UISegmentedControl

，旨在在3种地图视图“标准”、“混合”和“卫星”之间切换。我在“.addTarget”行上遇到以下错误

“源文件中的编辑器占位符”

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请尝试一下……

这里发生了一些事情。您需要使用一个#选择器并更改函数的声明以抑制第一个参数命名，否则您还必须在选择器中声明它

    let  segmentedControl = UISegmentedControl(items: ["Standard", "Hybrid", "Satellite"])
    segmentedControl.backgroundColor = UIColor.white.withAlphaComponent(0.5)
    segmentedControl.selectedSegmentIndex = 0

// EVENT LISTENER FOR SEGMENT CONTROL

segmentedControl.addTarget(nil, action: #selector(mapTypeChanged(_:)), for: .valueChanged)

func mapTypeChanged(_ segControl: UISegmentedControl){

    switch segControl.selectedSegmentIndex{
    case 0: mapView.mapType = .standard
    case 1: mapView.mapType = .hybrid
    case 2: mapView.mapType = .satellite
    default: break
    }
}

---

“在声明之前使用局部变量'mapTypeChanged'”您将在何处插入此代码？在ViewController内部？在UIViewController的loadView（）内部将其移动到“viewDidLoad”我正在以编程方式创建地图视图，因此它是否应该不在loadView中\

let  segmentedControl = UISegmentedControl(items: ["Standard", "Hybrid", "Satellite"])
segmentedControl.backgroundColor = UIColor.white.withAlphaComponent(0.5)
segmentedControl.selectedSegmentIndex = 0

// EVENT LISTENER FOR SEGMENT CONTROL
segmentedControl.addTarget(self, action: "mapTypeChanged:", for: .valueChanged)

func mapTypeChanged() //removing the auto complete params
{
    switch segControl.selectedSegmentIndex{
    case 0:
        mapView.mapType = .standard
    case 1:
        mapView.mapType = .hybrid
    case 2:
        mapView.mapType = .satellite
    default:
        break
    }

}

    let  segmentedControl = UISegmentedControl(items: ["Standard", "Hybrid", "Satellite"])
    segmentedControl.backgroundColor = UIColor.white.withAlphaComponent(0.5)
    segmentedControl.selectedSegmentIndex = 0

// EVENT LISTENER FOR SEGMENT CONTROL

segmentedControl.addTarget(nil, action: #selector(mapTypeChanged(_:)), for: .valueChanged)

func mapTypeChanged(_ segControl: UISegmentedControl){

    switch segControl.selectedSegmentIndex{
    case 0: mapView.mapType = .standard
    case 1: mapView.mapType = .hybrid
    case 2: mapView.mapType = .satellite
    default: break
    }
}