I have 15 buttons on my app, which are displayed as an image. When I click on an image the getEventContact function is called which brings up a modal view controller. In this next view a contact is selected - the modal view is dismissed and the setEventContact function is run (to return the selected contact (which is its own class)).
Is there a way to determine the previous sender which triggered the getEventContact function as it could be one of 15 buttons.
-(IBAction)getEventContact:(id)sender {
[self performSegueWithIdentifier:#"selectContact" sender:self];
}
-(void)setEventContact:(Contact *)selectedContact
{
//do something
}
Cheers.
SomeType *someVariable;
-(IBAction)getEventContact:(id)sender
{
someVariable = sender;
[self performSegueWithIdentifier:#"selectContact" sender:self];
}
-(void)setEventContact:(Contact *)selectedContact
{
//not a real method
[someVariable someMethod];
}
Related
I am playing around with the new iOS 5 features and trying to rewriting one of my apps as pure iOS 5 app using the new storyboarding feature.
To cut a long story short, I have a start screen where the app tries to connect to a server if the user saved some login data, if not, it should ask for them.
Here is how I would do it. I create a Viewcontroller which is doing the connection thing in the viewDidLoad method. If there is no login data or the login is not successful, I need a to do a manual segue to the login screen.
Now is this even possible, or do I need 2 story boards for that ?
I have solved it by putting a login view without any segues (to or from it) like in the screenshot below:
Then, I used a custom class in the tab bar controller to show it whenever I need it.
In the tab bar controller class, I use 'viewDidLoad' to fire up the login view. To show the modal view, I do have a singleton thingy that stores some state, say BOOL isAuthenticated, where I do the magic:
- (void) performLoginIfRequired: (UIViewController *) source {
if (!self.isAuthenticated) {
NSLog(#"Is not authed");
UIStoryboard *storyboard = [UIApplication sharedApplication].delegate.window.rootViewController.storyboard;
UIViewController *loginController = [storyboard instantiateViewControllerWithIdentifier:#"loginScreen"];
[source presentModalViewController:loginController animated:YES];
} else {
NSLog(#"Is authe");
}
}
And, in my case, I wanted it to be shown when the app first starts, but also when it enters foreground again. So, I registered my tab bar controller with the notification center, so I get notified if the app is coming back:
-(void)viewDidLoad {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(willEnterForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];
}
In the willEnterForeground method, I do:
-(void) willEnterForeground: (NSNotification *)notification {
[[myStateThingy defaultState] performLoginIfRequired:self];
}
It sounds like you need to use the performSegueWithIdentifier method. Make sure both views are in the same storyboard, link them together using a Push segue, and give that segue a name. Then, from your first view controller's code simply call the performSegueWithIdentifier to perform a manual segue.
Hope this helps!
See also: Conditionally following a segue
Cheers,
Jesse L. Zamora
I had this same issue, and I solved it simply by doing the following: Instead of trying to segue to a login screen(modally or push), I made the login screen my root view controller. In the login view controller's viewWillAppear method, I check if someone's logged in already. If so, I push my home screen:
// mutableFetchResults is an array with my persistent Credentials object
if ([mutableFetchResults count] > 0) { // Someone's already logged in
[self performSegueWithIdentifier:#"Home" sender:self];
}
Also, in the Home screen view controller's viewWillAppear method, I hid the back button with this line, so the user can't go "back" to the login screen:
self.navigationItem.hidesBackButton = YES;
Finally, every page of my app has a "Sign Out" bar button on the top right. Signing out and putting the login screen up was as simple as this:
- (IBAction)signOutButtonPressed:(UIBarButtonItem *)sender {
MyAppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
[appDelegate signOutCurrentUser]; // this method in my app delegate deletes the current Credentials
[self.navigationController popToRootViewControllerAnimated:YES];
}
Hope that was simple enough!
After trying many different methods, I was able to solve this problem with this:
-(void)viewWillAppear:(BOOL)animated {
// Check if user is already logged in
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:#"log"] intValue] == 1) {
self.view.hidden = YES;
}
}
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
// Check if user is already logged in
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if ([[prefs objectForKey:#"log"] intValue] == 1) {
[self performSegueWithIdentifier:#"homeSeg3" sender:self];
}
}
-(void)viewDidUnload {
self.view.hidden = NO;
}
Hi guys i am trying an app this is my link http://web.missouri.edu/~dnk6y2/Shealth%20app/
1.when i click on a annotation it will go inti an another view when i click show bulding it pop back the same view with single annotation and the code iam using for this is
-(void)viewWillAppear:(BOOL)animated
{
if ((i%2==0)) {
[mapView addAnnotations:djObjects];
i++;
}
else
{
if((show1==YES))
[mapView addAnnotation:annotation];
else
[mapView addAnnotations:djObjects];
// i++;
}
}
the app is working fine when i press back button even it is showing one annotation where i need all the annpotaions to come down....
so my question is can i set an action to an back button i have gone thru the apple documentation but i have no clue...
I assume that you're using a UINavigationController. UINavigationBarDelegate is the delegate class and it implements -navigationBar:shouldPopItem. You can put the action you want to trigger in that method.
Alternately, you can put it in -viewWillDisappear after checking that the view is disappearing because it was popped from the stack:
-(void) viewWillDisappear:(BOOL)animated {
if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) {
// action code here
}
[super viewWillDisappear:animated];
}
I need to fully UNLOAD the flipview don't ask me why but i NEED to. i have tried [super release]; and it didnt work below is my back button and then the did finish. Please help me to unload the view.
on the first view which gets activated once the flipview has finished.
- (void)flipViewControllerDidFinish:(FlipViewController *)controller
{
[self dismissModalViewControllerAnimated:YES];
}
on the flip view which is a button that hides the flip view just hides doesn't unload
- (IBAction)Back:(id)sender
{
[self.delegate flipViewControllerDidFinish:self];
}
[myFlipViewController.view removeFromSuperview];
I am sure this is in the Apple documentation or must have been answered somewhere on this forum, since it seems so basic, but I could not find it nor a particularly elegant solution myself.
What I have is a UIViewController that pushes an editing view on its navigation stack. The editing view has a bunch of UITextFields in it. If one of them is being editing when the back button is touched, the original view's ViewWillAppear method is called before either the UITextField delegate methods of textFieldShouldEndEditing or textFieldDidEndEditing, or the IB linked action textFieldEditingEnded method are called.
Here is some code that I hope will make it clearer:
In the UIViewController:
- (void) viewWillAppear: (BOOL) animated {
[super viewWillAppear: animated];
NSLog( #"Entering view will appear for master view" );
nameLabelField.text = objectToEdit.name;
}
- (IBAction) editMyObject: (id) sender {
NSLog( #"Editing the object" );
EditViewController *evc = [[EditViewController alloc] initWithNibName: #"EditTableView" bundle: nil];
evc.editedObject = objectToEdit;
[self.navigationController pushViewController: evc animated: YES];
[evc release];
}
In the EditViewController <UITextFieldDelegate>:
- (void) viewWillAppear: (BOOL) animated {
[super viewWillAppear: animated];
nameField.text = editedObject.name;
}
- (void) viewWillDisappear: (BOOL) animated {
[super viewWillDisappear: animated];
NSLog( #"In viewWillDisappear" );
if( [self.navigationController.viewControllers indexOfObject: self] == NSNotFound ) {
NSLog( #"-- We are not in controller stack... the back button has been pushed" );
}
}
- (BOOL) textFieldShouldEndEditing: (UITextField *) textField {
NSLog( #"In textFieldShouldEndEditing" );
// Store text field value here???
// editedObject.name = nameField.text;
return YES;
}
- (void) textFieldDidEndEditing: (UITextField *) textField {
NSLog( #"In textFieldDidEndEditing" );
// Store text field value here???
// editedObject.name = nameField.text;
}
- (IBAction) textFieldEditingEnded: (id) sender {
NSLog( #"In textFieldEditingEnded" );
// Store text field value here???
// editedObject.name = nameField.text;
}
The log ends up with:
[...] Entering view will appear for master view
[...] Editing the object
[...] In viewWillDisappear
[...] -- We are not in controller stack... the back button has been pushed
[...] Entering view will appear for master view
[...] In textFieldShouldEndEditing
[...] In textFieldEditingEnded
[...] In textFieldDidEndEditing
I want to set self.editedObject.name = nameField.text before the label gets set in viewWillAppear for the UIViewController.
I thought about in the viewWillDisappear method for the EditViewController checking to see if any of my text fields are currently the first responder and if so getting their text and storing it, but this seems like such a kludge that will be a pain to maintain if I add or change text fields.
I can also implement the textFieldEditingChanged IB linked action to set the text in the edited object after every keystroke but this is also quite a bit of overhead since I have to figure out which text field I am in every keystroke (remember I only showed name but there are a whole bunch of them).
All I need is for the editing to be ended or to know the editing will be ended before viewWillAppear is called in the UIViewController so the nameFieldLabel is properly set.
OK, I figured out a simple solution after a lot of web-surfing, forum reading, and manual reading. It was, as I suspected, very simple, only one line of code added. In the viewWillDisappear method of the EditViewContorller I simply added:
[self.view.window endEditing: YES];
Now textFieldShouldEndEditing, textFieldEditingEnded, and textFieldDidEndEditing all get fired off before the viewWillAppear of the master view does.
So now the viewWillDisappear method looks like:
- (void) viewWillDisappear: (BOOL) animated {
[super viewWillDisappear: animated];
NSLog( #"In viewWillDisappear" );
// Force any text fields that might be being edited to end so the text is stored
[self.view.window endEditing: YES];
}
And the methods already in place to handle the 'Return' on the keyboard also handle the 'Back' button on the Navigation controller.
Thank you Aaron and Jeff for your assistance and helping me think this through.
Why not just create your own Back button with that logic in its action method?
I would think that from a UX perspective, you should display an alert to determine if the user wants to cancel the edit action they were in the middle of before exiting the current view.
By alerting the user, you can see if they hit the button by accident or if they did decide to leave the view, take the appropriate action.
// add this to the field(s) to be edited, selector will be called as the changes
// are being made... still difficult to handle a cancel, but should work
[objectToEdit addTarget:self action:#selector(updateNameField:)
forControlEvents:UIControlEventEditingChanged];
additional code here...
// the method called to update object from parent view
- (void)updateNameField:(id)sender {
<OBJECT TO UPDATE>.text = ((UITextField *)sender).text;
}
so basically in my app delegate i have a navigation.controller
This navigation controller has a view of a class named MainScreen.
In MainScreen.m , i have a IBAction which will bring me to a SelectionScreen.m page by pushing it. here is the coding for it
SelectionScreen *aSelectionScreenViewController = [[SelectionScreen alloc]initWithNibName:#"SelectionScreen" bundle:nil];
[self.navigationController pushViewController:aSelectionScreenViewController animated:YES];
[aSelectionScreenViewController release];
So how do i check if my current navigationController.view = this selectionscreen.view?
The reason for checking which current view it is, is because when i receieve a push notification, i would want to automatically switch to this SelectionScreen.m page and invoke some methods within it. But this checking can only be done in the appDelegate because the didReceiveRemoteNotification method is located in there.
This is how i'm doing it
for example if you have three ViewControllers ,and any of those have possibility to be pushed by NavigationController:
ViewControllerA
ViewControllerB
ViewControllerC
Then what you need to do is:
-(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
{
if ([[self.navigationController topViewController] isKindOfClass:[ViewControllerA class]]) {
//do sth
}
if ([[self.navigationController topViewController] isKindOfClass:[ViewControllerB class]]) {
//do sth
}
if ([[self.navigationController topViewController] isKindOfClass:[ViewControllerC class]]) {
//do sth
}
}//end of code
One way is to save selectionScreenViewController as a property of your app delegate, then:
if (self.navigationController.topViewController == self.selectionScreenViewController) {
//...
}
else {
//...
}
Hey guys, i did it in a simple way. In every view controller i had, i removed all objects and assigned an object to an array in the appdelegate. So this way, everytime i go to a new view, the value is different.
So in appdidrecieveremotenotification, i can check that array and decide on what to do accordingly.
Its just a simple way of checking.