我创建了一个类«Chargement»,它允许显示带有加载的警报并关闭它。
import Foundation
class Chargement {
var alert : UIAlertController;
var message : String = NSLocalizedString("PleaseWait", comment:"") ;
let loadingIndicator : UIActivityIndicatorView;
init(message : String?) {
if(message != nil){
self.message = message!;
}
self.alert = UIAlertController(title: nil, message: self.message, preferredStyle: UIAlertControllerStyle.alert)
self.loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 4, width: 40, height: 60))
}
func showLoading(view : UIViewController){
loadingIndicator.hidesWhenStopped = true
loadingIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
loadingIndicator.startAnimating();
alert.view.addSubview(loadingIndicator)
view.present(alert, animated: true, completion: nil)
}
func closeLoading(){
alert.dismiss(animated: true, completion: nil)
}
}
当我在没有UICollectionView
的controllerView中使用我的类“Chargement”时,它可以用作例如:
class ViewController : UIViewController{
let loadingView : Chargement = Chargement(message: nil);
override func viewDidLoad() {
super.viewDidLoad();
loadingView.showLoading(view: self);
}
@IBAction func btn_Action(_ sender: UIButton) {
self.loadingView.closeLoading();//it works
}
}
但是当我在带有UICollectionView
的controllerView中使用它时,警报显示有效,但它不会关闭。
class TTwoViewController: UIViewController,UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout {
let loadingView : Chargement = Chargement(message: nil);
@IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad();
loadingView.showLoading(view: self);
loadingData();
}
func loadingData() {
dataManager().getData(num: 1, completion: {
(data, messages) in
self.loadingView.closeLoading(); //it don't work
DispatchQueue.main.async(execute: {
self.collectionView.reloadData();
//self.loadingView.closeLoading(); //it don't work
})
})
}
}
如果您只想显示活动指示器,可以使用NVActivityIndicatorView简化整个过程:
override func viewDidLoad() {
super.viewDidLoad();
let activityData = ActivityData()
NVActivityIndicatorPresenter.sharedInstance.startAnimating(activityData)
NVActivityIndicatorPresenter.sharedInstance.setMessage("Please Wait")
loadingData();
}
func loadingData() {
dataManager().getData(num: 1, completion: { (data, messages) in
DispatchQueue.main.async {
self.collectionView.reloadData()
NVActivityIndicatorPresenter.sharedInstance.stopAnimating()
}
})
}