I want to be notified when the orientation of the device changes. I've setup a test method that's suppose to receive the notification. I'm trying several different observers to achieve that, and none of them are working. Why isn't testMethod being fired?
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
// register for orientation change notification
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(testMethod) name:#"UIDeviceOrientationDidChangeNotification" object:nil];
[[NSNotificationCenter defaultCenter] addObserver: self
selector: #selector(testMethod)
name: UIApplicationWillChangeStatusBarOrientationNotification
object: nil];
[[NSNotificationCenter defaultCenter] addObserver: self
selector: #selector(testMethod)
name: UIApplicationDidChangeStatusBarOrientationNotification
object: nil];
}
- (void)testMethod
{
NSLog(#"phone was rotated");
}
I accidentally had the rotation lock engaged on my phone. Always test on more than one phone!
You need to use the Orientation notification, which is UIDeviceOrientationDidChangeNotification. Do not put it inside the #"UIDeviceOrientationDidChangeNotification" because you dont know the actual content of the constant which is UIDeviceOrientationDidChangeNotification. It appears you are using a view controller. You should use willRotateToInterfaceOrientation:duration: and didRotateFromInterfaceOrientation:
end of the bool type something set the orientation .write return yes in all end of the view ..orientation in potrait and landscape mode takeplace
Related
I'm creating a subclass of UIView that needs to relayout its subviews when the orientation changes.
it needs to be able to "plug in anywhere" without any extra code so I'd rather not rely on the UIViewController methods to detect the autorotation
Is there anyway for the UIView to know when the orientation has changed?
How about a notification like this to detect the orientation change??
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
But, before that you need to register for generating notifications like this.
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
I found that for me this worked better than the UIDeviceOrientationDidChangeNotification:
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("layoutControls"), name: UIApplicationDidChangeStatusBarOrientationNotification, object: nil)
I didn't even need to add the first line with beginGeneratingDeviceOrientationNotifications.
In Swift, it will be done like this:
NotificationCenter.default.addObserver(self, selector: #selector(orientationChange(inNotification:)), name: NSNotification.Name.UIApplicationDidChangeStatusBarOrientation, object: nil)
#objc private func orientationChange(inNotification:Notification) -> Void {
// handle notification
}
I'm trying to pass an object between 2 VCs, from a popover to the detail view of split view controller.
I think I need to use NSNotificationCenter.
I tried this but can't seem to get it to work.
In didSelectRow of popover
[[NSNotificationCenter defaultCenter] postNotificationName:#"PassObject" withObject:objectToPass];
In detail VC
- (void) didReceiveNotificationPassObject:(NSNotification*)notification
{
YourObjectClass *theObject = (YourObjectClass*)notification.object;
}
- (void)viewDidLoad
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(didReceiveNotificationPassObject:) name:#"PassObject" object:nil];
}
Probably just a typo when entering the question but in the first line where you post the notification
[[NSNotificationCenter defaultCenter] postNotificationName:#"PassObject" withObject:objectToPass];
the method signature is wrong - it should be 'object:objectToPass' not 'withObject:objectToPass'. The line you have there will compile with a warning and crash at runtime.
Aside from that all the logic seems fine.
What is the problem you are facing? Does didReceiveNotificationPassObject: hit? If it doesn't, you could verify that viewDidLoad executes before didSelectRow.
Use [[NSNotificationCenter defaultCenter] postNotificationName:#"PassObject" object:objectToPass]; instead of [[NSNotificationCenter defaultCenter] postNotificationName:#"PassObject" withObject:objectToPass];
Also, don't forget to removeObserver in viewDidUnload.
HTH,
Akshay
A fast and easy solution to notify with multiple parameters is to call the notification it like this
[[NSNotificationCenter defaultCenter] postNotificationName:#"shareButton" object:#"camera"];
Where "camera" acts like your parameter. Then
- (void)shareButton:(id)sender
{
NSString *kindOf = [sender object];
if ([kindOf isEqualToString:#"camera"]) {
// Your code goes here
}
}
How can I center an activity indicator programmatically regardless of screen orientation?
Try setting the center property of your activity view, like this:
activity.center = CGPointMake(self.view.frame.size.width/2,self.view.frame.size.height/2);
In viewDidLoad, register for notifications for the device rotation:
- (void)viewDidLoad {
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:UIDeviceOrientationDidChangeNotification object:nil];
}
and implement didRotate:
-(void)didRotate:(NSNotification *)notification {
if (activity) {
activity.center = CGPointMake(self.view.frame.size.width/2,self.view.frame.size.height/2);
}
}
I suggest you use https://github.com/jdg/MBProgressHUD
Which is a great library for doing all kinds of "Loading" screens.
i need to dismiss my uiimagepicker modal viewcontroller automatically when the application enters the background.i tried to put the code to dismissmodalviewcontroller code in viewdiddissappear method,but its not being called.so i made a reference to the viewcontroller in appdelegate and tried to put it in the applicationdidenterbackgroundmethod but still it is not working.can someone point out the right way to do this
Try to add an NSNotificationCenter observer for UIApplicationDidEnterBackgroundNotification in the UIViewController that you want to dismiss. Use the selector to dismiss the modalview
- (void)viewWillAppear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] addObserver: self
selector: #selector(didEnterBackground:)
name:UIApplicationDidEnterBackgroundNotification
object:nil];
}
- (void)viewWillDisappear:(BOOL)animated
{
[[NSNotificationCenter defaultCenter] removeObserver: self
name:UIApplicationDidEnterBackgroundNotification
object:nil];
}
- (void)didEnterBackground:(NSNotification*)note
{
[self.navigationController dismissModalViewAnimated:NO];
}
Best way to remove the modal when app is moving to background and it works fine .
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(dismissView:)
name:UIApplicationDidEnterBackgroundNotification object:nil];
}
- (void)dismissView:(id)sender {
[self dismissModalViewControllerAnimated:YES];
}
- (void)dealloc {
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
Also you can remove observer like this
[[NSNotificationCenter defaultCenter] removeObserver: self
name:UIApplicationDidEnterBackgroundNotification
object:nil];
I don't think you need to go through all that.
From the docs:
If you present several modal view controllers in succession, and thus build a stack of modal view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack.
Try calling [self dismissModalViewController:NO] from the parent view controller in your implementation of - (void) viewDidUnload.
This is untested, but the docs imply that it should do the job for you.
every UIViewController has a method called willRotateToInterface.
Is it possible to do this within a UIView too?
Does this match the idea of model view controller ?
The only way I can think of is to send the event from the UIViewController to the UIView.
Is there a global variable for the current orientation?
Observe UIDeviceOrientationDidChangeNotification:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(orientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
...
- (void)orientationDidChange:(NSNotification *)note
{
NSLog(#"new orientation = %d", [[UIDevice currentDevice] orientation]);
}
UIDevice Class Reference
I should note that yo uneed to add -beginGeneratingDeviceOrientationNotifications when you want these notifications to be sent, and call -endGeneratingDeviceOrientationNotifications when you want them to stop. There is a battery impact of generating these, so you should only do so when your view is on screen. UIViewController does all this for you, so if you have a view controller, it is worth letting it do the work.
If you just want to adjust view to new size/layout when orientation changes, you should just override its layoutSubviews method.
It will be called whenever size of the view changes, which usually happens when view is rotated.
You can subscribe to a global notification and get a call when the device is rotated, it wont do anything for you though..
[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(didRotate:)
name:#"UIDeviceOrientationDidChangeNotification" object:nil];