In a popover page, I'm trying to store some data in CoreData, and I need to show a loading view until the process is done.
I found a good and easy way, using a alert controller to show a loading label. In the function, I added a shouldPresent Boolean to make it false when the coreData process is done and hide the alert.

private func presentLoadingView(shouldPresent: Bool) {
     let alert = UIAlertController(title: nil, message: "Retrieving Owner Data", preferredStyle: .alert)
     let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 3, y: 5, width: 50, height: 50))
     loadingIndicator.hidesWhenStopped = true
     loadingIndicator.style = UIActivityIndicatorView.Style.medium
     loadingIndicator.startAnimating()

     alert.view.addSubview(loadingIndicator)
     presentAnimated(alert)
        
     if !shouldPresent {
        alert.dismiss(animated: true)
     }
  }

The problem is, when I use

dismiss(animated: true)

the entire popover will be dismissed and when I use

alert.dismiss(animated: true)

Nothing happen, could anyone help me on this. Thanks in advance.

CodePudding user response：

Try replaceing

    presentAnimated(alert)
   
if !shouldPresent {
   alert.dismiss(animated: true)
}

with

    if shouldPresent {
    presentAnimated(alert)
}

It seems it will do the work , accroding to your example code.

CodePudding user response：

I think using alert view for loading is not good enough for your needs.

You can use this extension easily for showing a loading view.

extension UIViewController{
    func showActivityIndicator(){
        DispatchQueue.main.async {[weak self] in
            guard let self = self else {return}
            let indicator = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
            indicator.backgroundColor = UIColor.init(hexString: "#010101").withAlphaComponent(0.6)
            indicator.layer.cornerRadius = 6
            indicator.center = self.view.center
            indicator.hidesWhenStopped = true
            indicator.color = UIColor(hexString: "#FFEE00")
            indicator.style = UIActivityIndicatorView.Style.large
            indicator.startAnimating()
            self.view.isUserInteractionEnabled = false
            indicator.tag = 1000000
            for subView in self.view.subviews{
                if subView.tag == 1000000{
                    print("Already Added")
                    return
                }
            }
            self.view.addSubview(indicator)
        }
    }
    func hideActivityIndicator(){
        DispatchQueue.main.async { [weak self] in
            guard let self = self else {return}
            let indicator = self.view.viewWithTag(1000000) as? UIActivityIndicatorView
            indicator?.stopAnimating()
            indicator?.removeFromSuperview()
            self.view.isUserInteractionEnabled = true
            indicator?.isHidden = true
        }
    }
}

In your view controller just call self.showActivityIndicator() when you want to show loader and call self.hideActivityIndicator() for dismiss the loader.