如何使用子视图卸载 uiView

Question

I am having tough time figuring out how to unload my UIView.

So Here is what I am doing.

I have a UI View class

@protocol JitsiViewDelegate <NSObject>

@optional
- (void)meetingEnded;
@end

@interface JitsiView : UIView

@property (nonatomic, nullable, weak) id<JitsiViewDelegate> delegate;
- (void)join:(JitsiMeetingConfig*)config;
@end

Where join (.m) file looks like this

- (void) join:(JitsiMeetingConfig*)config
{
    RCTBridge *bridge = [[Jitsi sharedInstance] getReactBridge];
  rootView = [[RNRootView alloc] initWithBridge:bridge
                                moduleName: @"JitsiTest"
                              initialProperties: [self getInitialProperties:config]];
  rootView.backgroundColor = self.backgroundColor;
  // Add rootView as a subview which completely covers this one.
          [rootView setFrame:[self bounds]];
        rootView.autoresizingMask
            = UIViewAutoresizingFlexibleWidth
                | UIViewAutoresizingFlexibleHeight;
    [self addSubview:rootView];
}

In above

RNRootView is this

and RCTBridge would be this

I am using this in a swift project

import UIKit
import JitsiSdk;

class ViewController: UIViewController {
    @IBOutlet weak var videoButton: UIButton?
    fileprivate var JitsiView: jitsiView?
    fileprivate var config: JitsiMeetingConfig?
    
    override func viewDidLoad() {
        super.viewDidLoad()

       //Config (removed code intentionally as it wasn't realvent) 

    }
    
    @IBAction func joinMeeting(_ sender: Any) {
                let jitsiView = JitsiView(frame: CGRect(x: 0, y: 0, width: self.view.bounds.size.width, height:self.view.bounds.size.height ))
                .delegate = self
                self.jitsiView = jitsiView;
                self.view.addSubview(jitsiView)
                jitsiView.join(config);
    }
    
    fileprivate func onMeetingEnded() {
            if(jitsiView != nil) {
                jitsiView?.removeFromSuperview()
            }
        }
}


extension ViewController: JitsiViewDelegate {
    func meetingEnded() {
        onMeetingEnded()
    }
}

Here on meetingEnded, I want to remove JitsiView and show the content which were there in my view controller before loading JitsiMeetView but the current code is throwing following error

'NSInternalInconsistencyException', reason: 'Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread.'

Can someone help me in understanding that why I am getting this error and how I can fix it?

Answer 1

Modifications to the layout engine must not be performed from a background thread after it has been accessed from the main thread.

This means that you are trying to call onMeetingEnded() on a background thread. All UI work must happen on main/UI thread.

Here's what you can do -

func meetingEnded() {
    DispatchQueue.main.async { [weak self] in
        self?.onMeetingEnded()
    }
}