• 全文引用自 https://gist.github.com/IMcD23/1fda47126429df43cc989d02c1c5e4a0, 仅作为笔记, 侵删!

• 其他参考资料: https://www.raywenderlich.com/177890/swizzling-in-ios-11-with-uidebugginginformationoverlay

// Used for swizzling on iOS 11+. UIDebuggingInformationOverlay is a subclass of UIWindow
@implementation UIWindow (DocsUIDebuggingInformationOverlaySwizzler)

- (instancetype)swizzle_basicInit {
    return [super init];
}

// [[UIDebuggingInformationOverlayInvokeGestureHandler mainHandler] _handleActivationGesture:(UIGestureRecognizer *)]
// requires a UIGestureRecognizer, as it checks the state of it. We just fake that here.
- (UIGestureRecognizerState)state {
    return UIGestureRecognizerStateEnded;
}

@end
  
@implementation DebuggingOverlay
  
+ (void)toggleOverlay {
    id debugInfoClass = NSClassFromString(@"UIDebuggingInformationOverlay");

    // In iOS 11, Apple added additional checks to disable this overlay unless the
    // device is an internal device. To get around this, we swizzle out the
    // -[UIDebuggingInformationOverlay init] method (which returns nil now if
    // the device is non-internal), and we call:
    // [[UIDebuggingInformationOverlayInvokeGestureHandler mainHandler] _handleActivationGesture:(UIGestureRecognizer *)]
    // to show the window, since that now adds the debugging view controllers, and calls
    // [overlay toggleVisibility] for us.
    if (@available(iOS 11.0, *)) {
        id handlerClass = NSClassFromString(@"UIDebuggingInformationOverlayInvokeGestureHandler");
        
        UIWindow *window = [[UIWindow alloc] init];
        
        static dispatch_once_t onceToken;
        dispatch_once(&onceToken, ^{
            // Swizzle init of debugInfo class
            Method originalInit = class_getInstanceMethod(debugInfoClass, @selector(init));
            IMP swizzledInit = [window methodForSelector:@selector(swizzle_basicInit)];
            method_setImplementation(originalInit, swizzledInit);
        });
        
        id debugOverlayInstance = [debugInfoClass performSelector:NSSelectorFromString(@"overlay")];
        [debugOverlayInstance setFrame:[[UIScreen mainScreen] bounds]];
        
        id handler = [handlerClass performSelector:NSSelectorFromString(@"mainHandler")];
        [handler performSelector:NSSelectorFromString(@"_handleActivationGesture:") withObject:window];
    } else {
        id debugOverlayInstance = [debugInfoClass performSelector:NSSelectorFromString(@"overlay")];
        [debugOverlayInstance performSelector:NSSelectorFromString(@"toggleVisibility")];
    }

}