I am having a hard time how to figure out when a user has selected & copied text the default iOS way:
canPerformSelector works before presenting this menu, but I am interested in knowing after the user has pressed the copy button.
Thank You
Use NSNotification as observer for UIPasteboardChangedNotification: then every time user copies it will call a method which you specified in Notification observer
Something like this
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(ClipBoardChanged) name:UIPasteboardChangedNotification object:nil];
-(void)ClipBoardChanged{
NSLog(#"ClipBoard data changed %#",[UIPasteboard generalPasteboard].string);
}
Related
I have created a method to check the status of a server in my viewcontroller, I need to check this, everytime I will open the app.
I call [self checkStatus]; from viewWillAppear and viewDidLoad, but when I open the app, by clicking home button, and I try to open the app again (clicking the app icon in applications) this method is not called. I have a NSLog to view when it is launched or not.
I'm frustrated. Thanks for your help.
You can react to app changes using NotificationCenter:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(doSomething:) name:UIApplicationDidBecomeActiveNotification object:nil];
BTW: don't forget to removeObserver when you don't need it!
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidBecomeActiveNotification object:nil];
You can also use UIApplicationWillEnterForegroundNotification etc, depending what do you need.
You should read about app lifecycle on Apple Developer pages :). Read:
AppleDeveloperLink Especially section: "Execution States for Apps" to know more about app lifecycle.
StackOverflowLink to know more about view lifecycle.
iOS is not calling those methods again, but the delegate methods in the AppDelegate. You have to propagate the message to your controllers then.
I hope this will help you: https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIApplicationDelegate_Protocol/
I have a widget that I would like to call back to my main app so as to make a call to the server to update data. I looked into delegation, but registering the widget's view controller as a delegate didn't seem very practical. So I moved on to trying to use NSNotificationCenter. I have set it up, but the selector is not being called. In my main iOS app I have this in the viewDidLoad method.
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(loadNewData:)
name:kUpdateData
object:nil];
And at the bottom of that file I have this:
/**
* Updates the table when the today widget is called for updated info
**/
- (void)loadNewData:(NSNotification *) notification
{
[self loadTableData];
}
That's in my main app. Now, in my notification center widget/extension, I make this call:
[[NSNotificationCenter defaultCenter]
postNotificationName:kUpdateData
object:nil];
The postNotificationName being passed in, `kUpdateData', is a constant that is resolved to #"updateData". I can see in the debugger that the postNotificationName method is being called, but the main app is not responding to it (regardless of it is in the foreground or the background). What am I doing wrong?
As a side note, the only reason I am doing this is to remove the need for repetitive code and re-implementing things I have already made.
As far as i know extension cant access or call main app methods... what can do is either do the server execution in extension or set a value in shared NSUserDefault so when your app is brought to foreground you can check this value and connect with server accordinly.
I have a UIView ,I want it to display in a new day.For example,today I launch my app,and that UIView comes to my view,but after this,I can't see that UIView until tomorrow.
So I want to know how to judge whether it is a new day to display the UIView?
You need to register for the UIApplicationSignificantTimeChangeNotification notification.
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(timeChange) name:UIApplicationSignificantTimeChangeNotification object:nil];
Then in the timeChange method (or whatever you call it) update your view.
Don't forget to unregister:
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationSignificantTimeChangeNotification object:nil];
This notification is sent at midnight, if the user changes the time on their device, or the timezone changes. If your app is in the background when the change happens, it will get notified when the app returns to the foreground.
I have read over many stack overflow questions where people ask to terminate their app oppose to let it run in the background.
The main answer I found was to set the application does not run in background BOOL to YES in my info.plist
I have done this and cleaned my project but still my application runs in the background when the user presses the home button. This solution simply does not work.
What can I do to make my application quit when a user presses the home button.
My app is currently running on iOS 6.
Any help is appreciated :)
This answer is for your first comment, not the original question. Have your iPod view controller register for the UIApplicationDidEnterBackgroundNotification notification. The implementation should stop the music. This is a much better user experience than choosing to have your app terminate on suspend.
// Put this in a good place like viewDidLoad
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(backgrounding) name:UIApplicationDidEnterBackgroundNotification object:nil];
// Handle the notification
- (void)backgrounding {
// app is leaving the foreground, stop the music
}
// In your dealloc method add:
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidEnterBackgroundNotification object:nil];
I have a scenario where I'd like to have a handler that gets triggered when the user presses the language change(globe icon) on the keyboard for iOS.
How I may achieve that?
Thanks
The following should work:
You would have to use a UIKeyboard notification within your code
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWillBeHidden:)
name:UIKeyboardWillHideNotification object:nil];
Then within your keyboardWillBeHidden: or similarly named method use the answer (link below) which returns you a two letter code for the currently selected language.
Link: Getting current device language in iOS?
So your method keyboardWillBeHidden: method is called when the keyboard is hidden reads from the system the keyboard language option that is currently selected.
Thats the theory, I haven't tried this myself, good luck.