How to show activity indicator while tableView loads?

Question

When I switch between my tabs it loads some seconds and I want to know that my data is loading. For that I decided to add an activity indicator.

I wrote a little function:

func showActivityIndicator() {     dispatch_async(dispatch_get_main_queue()) {         self.spinner = UIActivityIndicatorView(activityIndicatorStyle: .WhiteLarge)         self.spinner.frame = CGRect(x: 0.0, y: 0.0, width: 80.0, height: 80.0)         self.spinner.center = CGPoint(x:self.loadingView.bounds.size.width / 2, y:self.loadingView.bounds.size.height / 2)          self.loadingView.addSubview(self.spinner)         self.view.addSubview(self.loadingView)         self.spinner.startAnimating()     } } 

that will show my indicator. And try to use it when I tapped from my infoController to button:

@IBAction func goToMainFromInfo(sender: AnyObject) {         self.showActivityIndicator()         self.performSegueWithIdentifier("fromMainToInfoWActivity", sender: nil)         self.hideActivityIndicator()     } } 

I show it before segue perform and hide after. It doesn't help me. When I did try to use sync:

@IBAction func goToMainFromInfo(sender: AnyObject) {     dispatch_async(dispatch_get_main_queue()) {         self.showActivityIndicator()         self.performSegueWithIdentifier("fromMainToInfoWActivity", sender: nil)         self.hideActivityIndicator()     } } 

But it doesn't help too. When I press to tab it opacity becomes 0.5 and I wait while it loading. But I do not see my activity indicator.

What is the problem?

Answer 1

Just try this:

var indicator = UIActivityIndicatorView()  func activityIndicator() {     indicator = UIActivityIndicatorView(frame: CGRectMake(0, 0, 40, 40))     indicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray     indicator.center = self.view.center     self.view.addSubview(indicator)     } 

And where you want to start animating

indicator.startAnimating() indicator.backgroundColor = UIColor.whiteColor() 

For stop:

indicator.stopAnimating() indicator.hidesWhenStopped = true 

Note: Avoid the calling of start and stop at the same time. Just give some conditions.

SWIFT : 4.2 Just try this:

var indicator = UIActivityIndicatorView()  func activityIndicator() {     indicator = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 40, height: 40))     indicator.style = UIActivityIndicatorView.Style.gray     indicator.center = self.view.center     self.view.addSubview(indicator)    } 

And where you want to start animating

activityIndicator() indicator.startAnimating() indicator.backgroundColor = .white 

For stop:

indicator.stopAnimating() indicator.hidesWhenStopped = true 

Answer 2

Swift 3.0

// UIView Extension

fileprivate var ActivityIndicatorViewAssociativeKey = "ActivityIndicatorViewAssociativeKey" public extension UIView {    var activityIndicatorView: UIActivityIndicatorView {         get {             if let activityIndicatorView = getAssociatedObject(&ActivityIndicatorViewAssociativeKey) as? UIActivityIndicatorView {                 return activityIndicatorView             } else {                 let activityIndicatorView = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 40, height: 40))                 activityIndicatorView.activityIndicatorViewStyle = .gray                 activityIndicatorView.color = .gray                 activityIndicatorView.center = center                 activityIndicatorView.hidesWhenStopped = true                 addSubview(activityIndicatorView)                  setAssociatedObject(activityIndicatorView, associativeKey: &ActivityIndicatorViewAssociativeKey, policy: .OBJC_ASSOCIATION_RETAIN_NONATOMIC)                 return activityIndicatorView             }         }          set {             addSubview(newValue)             setAssociatedObject(newValue, associativeKey:&ActivityIndicatorViewAssociativeKey, policy: .OBJC_ASSOCIATION_RETAIN_NONATOMIC)         }     } } 

// NSObject Extension

public extension NSObject {     func setAssociatedObject(_ value: AnyObject?, associativeKey: UnsafeRawPointer, policy: objc_AssociationPolicy) {         if let valueAsAnyObject = value {             objc_setAssociatedObject(self, associativeKey, valueAsAnyObject, policy)         }     }      func getAssociatedObject(_ associativeKey: UnsafeRawPointer) -> Any? {         guard let valueAsType = objc_getAssociatedObject(self, associativeKey) else {             return nil         }         return valueAsType     } } 

start animation

tableView.activityIndicatorView.startAnimating()

stop animation

tableView.activityIndicatorView.stopAnimating()

You can find more code in Magic