How to make the application detect a button press at home?

Question

I want to create it so that if the user clicks the home button and then returns to the application, the application recognizes this action and generates a message for the user to see (for example, welcome). I suppose I need to change appdelegate for this, but I don’t know how to do this to encode it ... can anyone lend a hand?

Answer 1

Whenever an application wakes up from the background .. it enters this delegate in the application delegate -

- (void)applicationWillEnterForeground:(UIApplication *)application { /* Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background. */ } 

You can show msg to the user in this delet

Also check out these delegates -

 - (void)applicationWillResignActive:(UIApplication *)application { /* Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state. Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game. */ } - (void)applicationDidEnterBackground:(UIApplication *)application { /* Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits. */ } - (void)applicationWillEnterForeground:(UIApplication *)application { /* Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background. */ } - (void)applicationDidBecomeActive:(UIApplication *)application { /* Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. */ } - (void)applicationWillTerminate:(UIApplication *)application { /* Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:. */ }