isHidden or view.removeFromSuperView are taking a long while - ios

Question

I'm trying to show a UITableView from a button, I tried 2 different ways:
One by showing by a UIStackView with was hidden from the beginning, and just show with "isHidden", another way with a view from another UIViewController, which is called with "didMove(toParentViewController: self)"
With both ways, the tableview is showing instantly, but to hide it again, that's taking forever.
I've tried to put the "isHidden = true" in "DispatchQueue.main.sync" to use the main thread, but still not working as I would like...
Any suggestions?
Here is some code of my application :
#IBAction func ProfilPicture1Pressed(_ sender: UIButton) {
let popUpTeamDog = storyboard?.instantiateViewController(withIdentifier: "selectTeamDogPopUp") as! SelectTeamDogPopUp
DispatchQueue.global().async(execute: {
DispatchQueue.main.sync{
self.addChildViewController(popUpTeamDog)
popUpTeamDog.view.frame = self.view.frame
self.view.addSubview(popUpTeamDog.view)
popUpTeamDog.didMove(toParentViewController: self)
}
})
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let dog: Dog
if(searching){
dog = searchArray[indexPath.row]
} else {
dog = dogs[indexPath.row]
}
let nameDog = dog.name
//let imgDog = UIImage(named: dog.image)
print(nameDog)
DispatchQueue.global().async(execute: {
DispatchQueue.main.sync{
self.view.removeFromSuperview()
}
})
So I can add that when I click on the searchBar, then select a dog, the tableView / View disappear instantly, so when the keyboard is activate, that's working well... Stranger things....

Answer 1

Your code uses main thread by default. So you don't have to use this DispatchQueue.global() and DispatchQueue.main. It's too slow.
So replace this
DispatchQueue.global().async(execute: {
DispatchQueue.main.sync{
self.addChildViewController(popUpTeamDog)
popUpTeamDog.view.frame = self.view.frame
self.view.addSubview(popUpTeamDog.view)
popUpTeamDog.didMove(toParentViewController: self)
}
})
with
self.addChildViewController(popUpTeamDog)
popUpTeamDog.view.frame = self.view.frame
self.view.addSubview(popUpTeamDog.view)
popUpTeamDog.didMove(toParentViewController: self)
and do the same with self.view.removeFromSuperview(). Replace this
DispatchQueue.global().async(execute: {
DispatchQueue.main.sync{
self.view.removeFromSuperview()
}
})
with
self.view.removeFromSuperview()