swift - 谷歌 API 自动完成

Question

我正在尝试在我的应用中实现自动完成功能。

我已经设置了一个带有按钮的 View Controller 并添加了下面的代码。

但是我不断收到以下错误:

Cannot assign value of type 'selectAddress' to type 'GMSAutocompleteViewControllerDelegate?'

在这一行:

autocompleteController.delegate = self

谁知道这是为什么？

import Foundation
import UIKit
import GoogleMaps
import GooglePlaces

class selectAddress: UIViewController, UISearchBarDelegate {

    // Present the Autocomplete view controller when the button is pressed.
    @IBAction func autocompleteClicked(_ sender: UIButton) {
        let autocompleteController = GMSAutocompleteViewController()
        autocompleteController.delegate = self
        self.present(autocompleteController, animated: true, completion: nil)
    }
}

extension ViewController: GMSAutocompleteViewControllerDelegate {

    // Handle the user's selection.
    func viewController(_ viewController: GMSAutocompleteViewController, didAutocompleteWith place: GMSPlace) {
        print("Place name: \(place.name)")
        print("Place address: \(place.formattedAddress)")
        print("Place attributions: \(place.attributions)")
        dismiss(animated: true, completion: nil)
    }

    func viewController(_ viewController: GMSAutocompleteViewController, didFailAutocompleteWithError error: Error) {
        // TODO: handle the error.
        print("Error: ", error.localizedDescription)
    }

    // User canceled the operation.
    func wasCancelled(_ viewController: GMSAutocompleteViewController) {
        dismiss(animated: true, completion: nil)
    }

    // Turn the network activity indicator on and off again.
    func didRequestAutocompletePredictions(_ viewController: GMSAutocompleteViewController) {
        UIApplication.shared.isNetworkActivityIndicatorVisible = true
    }

    func didUpdateAutocompletePredictions(_ viewController: GMSAutocompleteViewController) {
        UIApplication.shared.isNetworkActivityIndicatorVisible = false
    }

    func viewController(viewController: GMSAutocompleteViewController!, didFailAutocompleteWithError error: NSError!) {
        // TODO: handle the error.
        print("Error: ", error.description)
    }

}

Answer 1

您正在将委托(delegate)设置为 self，这是一个类型为 selectAddress 的类，但是您拥有的扩展符合 GMSAutocompleteViewControllerDelegate协议(protocol)是 ViewController 类型。如果您将其更改为 extension selectAddress: GMSAutocompleteViewControllerDelegate，您将被设置。