How to remove only user-added subviews from my UIView

问题

I'm trying to remove all the subviews that I've added to my view, so I've implemented a loop to iterate over the subviews with the following:

for subview in view.subviews {
    println(subview)
    //subview.removeFromSuperview()
}

I tested this by adding a UILabel to my view and then ran this code. The output contained my UILabel but also a _UILayoutGuide. So, my question is how can I determine if a subview is one that I added or one that the system added?

回答1:

If you just want to prevent the loop from removing the _UILayoutGuide (which is of class UILayoutSupport), try this:

for subview in self.view.subviews {
    if !(subview is UILayoutSupport) {
        print(subview)
        subview.removeFromSuperview()
     }
}

And generally speaking, if you'd like to prevent the removal of views other than the _UILayoutGuide and if you know the specific types of subviews you'd like to remove from your UIView, you can limit the subviews you remove to those types, ex:

for subview in view.subviews {
    if subview is ULabel {
        println(subview)
        subview.removeFromSuperview()
    }
}

回答2:

One option is to give all the views you add a specific tag. Then only remove them if they have that tag.

userCreatedView.tag = 100;

...

for subview in view.subviews {
    if (subview.tag == 100) {
        subview.removeFromSuperview()
    }
}

You could also keep an Array of all the subviews that the user has added then check to see if that subview is in your userAddedViewsArray

Or you could create a subclass of UIView for your user added views and then only remove the subviews that are that class

回答3:

i solve problem like this way.... first i added sub view

[self.view addSubview:genderPicker];

then remove only that subview from the view

[genderPicker removeFromSuperview];

回答4:

indicator on off by string input fun swift 2.2 and above

func activityonoff(viewcontroler:UIViewController,string:String){
let container: UIView = UIView()
let loadingView: UIView = UIView()
if string == "on"{
container.frame = viewcontroler.view.frame
container.center = viewcontroler.view.center
container.backgroundColor = UIColor.whiteColor()
container.alpha = 1
container.tag = 1

loadingView.frame = CGRectMake(0, 0, 80, 80)
loadingView.center = container.center
loadingView.backgroundColor = UIColor(red: 4/255, green: 68/255, blue: 68/255, alpha: 0.7)
loadingView.clipsToBounds = true
loadingView.layer.cornerRadius = 10

let actInd: UIActivityIndicatorView = UIActivityIndicatorView()
actInd.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
actInd.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.WhiteLarge
actInd.center = CGPointMake(loadingView.frame.size.width / 2,loadingView.frame.size.height / 2);
loadingView.addSubview(actInd)
container.addSubview(loadingView)
viewcontroler.view.addSubview(container)
actInd.startAnimating()
}
else{
    for v in viewcontroler.view.subviews{
        if v.tag == 1{
            v.removeFromSuperview()
        }
    }

}

}

来源：https://stackoverflow.com/questions/27237457/how-to-remove-only-user-added-subviews-from-my-uiview

标签

ios

swift

uiview

subviews