My alertview appears twice and requires 2 user clicks to dismiss.
- (void) showAlert: (NSString *) message
{
UIAlertView *av = [[UIAlertView alloc] initWithTitle:#"You chose"
message: message
delegate: self
cancelButtonTitle:#"Cancel"
otherButtonTitles:#"ok",nil];
av.tag = SLIDER_ALERT;
[av show];
}
I am then releasing the alertview in the delegate method "alertView: (UIAlertView *) alertView clickedButtonAtIndex: (int) index"
I suspect the problem is that I have built my own view hierarchy programmaticaly. I have one parent view for the viewcontroller. Under that i have 2 other views (parentView -> subview1 and subview2). I've tried to call [self.view addSubview: av] but that does not work. Neither does bringToFrontSubView:
Any help would be much appreciated
Peyman
The Alert code is fine (other than the release, mentioned in the comments).
[av show] is all that's required to show a view. You don't add UIAlertViews as subviews.
Call it after a delay of 0.1 sec [self performSelector:#selector(showAlert:) withObject:nil afterDelay:0.10];
Hope this will solve your problem.
With using autorelease the Alert View seems to be twice or 3 times. And for iOS4 it needs to be autoreleased otherwise it will crash.
Related
I'm having a terrible time getting a UIAlertView to work within my custom NSObject class. In the research I've done it appears it should be possible but here's what I've run into.
First, here's my code:
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
NSLog(#"clickedButtonAtIndex: %d", buttonIndex);
}
-(void)testAlertView {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"List Contains Items"
message:#"List contains items. Remove all items & delete?"
delegate:self
cancelButtonTitle:#"No"
otherButtonTitles:#"Yes", nil];
[alertView show];
}
If I set the delegate to self this code crashes as soon as I tap a button. If I set it to nil clickedButtonAtIndex is never called. I've tried with and without using the <UIAlertViewDelegate>.
I know someone will ask 'why are you doing this in NSObject instead of in your UIViewController?'. Primarily because I want to separate this code out so I can use it from multiple places in my app. But also because this is a small piece of a larger block of logic that makes sense to be on it's own.
Any ideas what I'm doing wrong?
Thanks,
Rich
I had the same problem using ARC. The root of the problem was the same. I solved it by putting my custom NSObject into a "strong" property to make sure the object exists as long as the calling object (an UIVIewCOntroller in my case) exists, so when the delegate of my alert view is called I still have my custom object around and the delegate method works fine.
Add the NSObject as strong property:
#import "Logout.h" // is NSObject
.
.
.
#property (nonatomic, strong) Logout *logout;
Then you will get the delegatemethods called in your NSObject.
Don´t forget to register the delegate for the UIAlertView:
#interface Logout () <UIAlertViewDelegate>
and in your method:
UIAlertView *a = [[UIAlertView alloc] initWithTitle:#"title"
message:#"message" delegate:self cancelButtonTitle:#"cancel"
otherButtonTitles:#"ok", nil];
[a show];
How To Present An Alert View Using UIAlertController When You Don't Have A View Controller. Detail description.
Yes, you can only use UIAlertController only in UIViewController classes. So how can we do it in NSObject classes. If you see the description link given above you will get to the answer. To summarise in a line for the above description: Create a new window above the the current window. This new window will be our viewController where we display alert. So using this viewController you can call the method [presentViewController: animated: completion:].
Answer:
dispatch_async(dispatch_get_main_queue(), ^{
UIWindow* window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
window.rootViewController = [UIViewController new];
window.windowLevel = UIWindowLevelAlert + 1;
NSString *msg=#“Your mssg";
UIAlertController* alertCtrl = [UIAlertController alertControllerWithTitle:#“Title" message:msg preferredStyle:UIAlertControllerStyleAlert];
[alertCtrl addAction:[UIAlertAction actionWithTitle:NSLocalizedString(#"Yes",#"Generic confirm") style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
// do your stuff
// very important to hide the window afterwards.
window.hidden = YES;
}]];
UIAlertAction *cancelAction= [UIAlertAction actionWithTitle:#"cancel" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
window.hidden = YES;
}];
[alertCtrl addAction:cancelAction];
//http://stackoverflow.com/questions/25260290/makekeywindow-vs-makekeyandvisible
[window makeKeyAndVisible]; //The makeKeyAndVisible message makes a window key, and moves it to be in front of any other windows on its level
[window.rootViewController presentViewController:alertCtrl animated:YES completion:nil];
});
would you please look at that piece of code:
/* This app is a game, the user can click an "abort" button anytime,
* and he/she is therefore asked for confirmation ("really abort game?")
*/
- (IBAction)btnAbortClicked:(id)sender {
UIAlertView *alert = [[UIAlertView alloc] init];
[alert setMessage:#"Really abort game?"];
[alert setDelegate:self];
[alert addButtonWithTitle:#"Yes"];
[alert addButtonWithTitle:#"No"];
[alert show];
[alert release];
}
/* Delegate method (I don't like it, I wish I had modal blocking windows) */
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
if (buttonIndex == 0)
[self quitGame];
}
/* pop the view controller */
- (void)quitGame {
[self.navigationController popToRootViewControllerAnimated:YES];
}
The problem is simple - but apparently not enough for me to solve. The UIViewController gets popped, but doesn't get deallocated. And the problem is strictly related to the UIAlertView, because if I just call quitGame from btnAbortClicked:, the view controller is popped and immediately deallocated.
Instead, it seems some mysterious entity retains it.
Can you help me? Thanks in advance.
Well, I think that you're still inside the alertView when clickedButtonAtIndex is called. I'd suggest moving to alertView:disDismissWithButtonIndex instead, so that you're called after the alertview disappears.
I'm having a similar issue to Anthony Chan's question, and after trying every suggested solution, I'm still stuck.
Somehow, only after interacting with my UIAlertView, I'm unable to dismiss the keyboard in another view of my app. It's as though the Alert is breaking my UITextField's ability to resignFirstResponder. Below I instantiate my UIAlertView, which then calls its didDismissWIthButtonIndex method. Then, I call the showInfo method, which loads another UIViewController.
UIAlertView *emailFailAlert = [[UIAlertView alloc] initWithTitle:#"Error"
message:#"error message text."
delegate:self
cancelButtonTitle:#"Not now"
otherButtonTitles:#"Settings", nil];
[emailFailAlert setTag:2];
[emailFailAlert show];
[emailFailAlert release];
Once the 'Settings' option is pressed, I'm calling this method:
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
if ([alertView tag] == 2) {
if (buttonIndex == 1){
[self showInfo:nil];
}
}
}
My showInfo method loads the other ViewController, via the code below:
- (IBAction)showInfo:(id)sender {
FlipsideViewController *fscontroller = [[FlipsideViewController alloc] initWithNibName:#"FlipsideView" bundle:nil];
fscontroller.delegate = self;
fscontroller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:fscontroller animated:YES];
[fscontroller release];
}
Upon clicking any textField in this Flipside VC, I'm unable to dismiss the keyboard as I normally can with - (BOOL)textFieldShouldReturn:(UITextField *)textField, and [textField resignFirstResponder]. I've omitted this code bc this question is getting long, but I'm happy to post if necessary.
The interesting part is that if I comment out the [self showInfo:nil] call made when the button is clicked and call it by clicking a test button (outside the alertView didDismissWithButtonIndex: method), everything works fine. Any idea what's happening here?
Thanks in advance!
When an alert, with more than one dismissal option, is called above a keyboard - the keyboard becomes un-dismissible with resignFirstResponder on the active textfield;
You will need to dismiss the keyboard before showing the alert.
Assuming your UITextField is called myTextField;
[myTextField resignFirstResponder]; //That's the only line I added
UIAlertView *emailFailAlert = [[UIAlertView alloc] initWithTitle:#"Error"
message:#"error message text."
delegate:self
cancelButtonTitle:#"Not now"
otherButtonTitles:#"Settings", nil];
[emailFailAlert setTag:2];
[emailFailAlert show];
[emailFailAlert release];
I hope this helps anyone who had to deal with this oddly obscure issue.
You should not call alertView:didDismissWithButtonIndex: directly. This delegate method will be executed automatically in all cases after the alert has disappeared. Otherwise the code will be run twice!
I have such error: when I click navigationbar.backItemButton I'm showing UIAlertView with two buttons. When I press on any of them application terminates just with EXC_BAD_ACCESS. Method - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex don't called. How can I solve it? Thanx!
//h - file
#interface DetailsTableViewController : UITableViewController <UITextFieldDelegate, UIAlertViewDelegate>
//m - file
- (void)viewWillDisappear:(BOOL)animated
{
//if changes unsaved - alert reask window
if (isDirty)
{
UIAlertView *message = [[UIAlertView alloc] initWithTitle:#"Save changes?"
message:#"Press YES if you want to save changes before exit, NO - other case."
delegate: self
cancelButtonTitle: #"NO"
otherButtonTitles: #"YES", nil];
[message show];
[message autorelease];
}
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
NSString *title = [alertView buttonTitleAtIndex: buttonIndex];
if([title isEqualToString: #"YES"])
{
[self saveBtnUserClick];
}
}
I think the problem is that after you tapped back button your current controller is removed from navigation stack and deallocated, so when alert tries to call its delegate methods it calls them on deallocated object which results in EXC_BAD_ACCESS error. To workaround the problem I see 2 obvious options (although there may be better solutions):
Extra retain your controller somewhere (in previous controller may be), but you need to find way to release it when you're done.
Create your custom button instead of standard "back" and just show alert when it tapped. Then in alert's delegate method pop your current controller from navigation stack.
Try Changing delegate to nil instead of self. It fixed my issue.
Is your view controller implementing the UIAlertViewDelegate? If not, add in you interface declaration before the { starts.
Also try NSLogging inside the clickedButtonAtIndex method and print the buttonIndex values and see the console.
Edit: Reading your post again, I guess you indeed have missed the UIAlertViewDelegate in your interface declaration.
Probably [message autorelease];
is you mistake use
[message release];
Because you have used [[UIAlertView alloc] init.....]; there for you should release the memory.
autorelease is something will work with the structure which memory is compiler dependent or you have not given the memory manually.
Enjoy.
"Try Changing delegate to nil instead of self. It fixed my issue." worked for me. Thanx
A UIAlertView is displayed if an error occurs. But in the meantime the view on which the UIAlertView were called has been dismissed (and therefore released). If the user clicks on OK the app crashes because a message to a released instance is sent. This will cause your app crashing:
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"test" message:#"test" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alertView show];
[alertView release];
alertView = nil;
[self.navigationController popViewControllerAnimated:YES];
I thought the UIAlertView is an independent unit. But it seems it isn't. Is there a way how I could avoid the app crashing (except not dismissing the view)?
The delegate is called when the UIAlertView is dismissed, so in your case:
delegate:self
Delegates are not retained, like an object added to an array, or a subview would be. So in your case, when you call:
[self.navigationController popViewControllerAnimated:YES];
self is most likely being released, and when the the user dismisses the alert, self is called, but has been dealloc'd so it no longer exists.
An easy way to check this is to put a logger statement, like NSLog(#"I'm gone"); in self's dealloc method, if it's ran, then you know your self isn't around anymore, and any messages sent to it will cause a crash.
Make the UIAlertView a retained property of your view controller so that you can refer to it in your dealloc, then set the alert view's delegate to nil when the view controller is deallocated.
Be sure to properly release the retained alert view once it's been dismissed and on dealloc.
For instance:
#interface MyViewController : UIViewController <UIAlertViewDelegate> {
UIAlertView *alertView;
}
#property (nonatomic, retain) UIAlertView *alertView;
#implementation MyViewController
#synthesize alertView;
- (void)showAlert {
if (alertView) {
// if for some reason the code can trigger more alertviews before
// the user has dismissed prior alerts, make sure we only let one of
// them actually keep us as a delegate just to keep things simple
// and manageable. if you really need to be able to issue multiple
// alert views and be able to handle their delegate callbacks,
// you'll have to keep them in an array!
[alertView setDelegate:nil];
self.alertView = nil;
}
self.alertView = [[[UIAlertView alloc]
initWithTitle:#"Error"
message:#"Something went wrong"
delegate:self
cancelButtonTitle:#"Cancel"
otherButtonTitles:#"Retry",nil] autorelease];
[alertView show];
}
- (void)alertView:(UIAlertView *)alertViewParam didDismissWithButtonIndex:(NSInteger)buttonIndex {
self.alertView = nil; // release it
// do something...
}
- (void)dealloc {
[alertView setDelegate:nil]; // this prevents the crash in the event that the alertview is still showing.
self.alertView = nil; // release it
[super dealloc];
}
The downside here is that you will not be able to handle the alert view's callback when the user dismisses it. However, since your controller is already gone/released, presumably you don't need to. If you do, you have to set the alert view's delegate to something that will persist.
If the UIAlertView object is to be usable from anywhere in the app, not just on the current view, then retain it inside something that is available from anywhere in the app, either some persistant root view controller under the entire possible view stack, or the app delegate.
Added:
This top level object can also retain the alert view's delegate until after it's done being needed (after alert view dismissal).
(People might wonder I am late by years in answering this question,but it might help someone else)
I guess your problem lies some where in popping the view controller,you are displaying the alert view and at the same time trying to navigate the user back to a view.I would recommend you to follow a hierarchal approach here i.e.:
First of all declare your alert view as a global object,i.e.
#property(nonatomic,retain) UIAlertView *sampleAlert;
Now write your alert view display code where ever desired,say for instance:
-(IBAction)buttonClicked:(id)sender
{
self.sampleAlert = [[UIAlertView alloc] initWithTitle:#"test" message:#"test" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[sampleAlert show];
[sampleAlert release];
}
Finally try to navigate the user to the desired view when the "Ok" button is pressed,i.e. you need to make use of alertView didDismissWithButtonIndex method,i.e.
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
if(alertView == sampleAlert)
{
[self.navigationController popViewControllerAnimated:YES];
}
}
Please note that if you have alert view with multiple buttons,you also need to check for button index for distinguishing actions,i.e. check using
if(alertView == sampleAlert && buttonIndex == 0)
{
//Do your stuff
}
else
{
//Do something else
}
This will definitely avoid application crash,thanks :)
Easier way that worked for me is to hold all the alert views in a Array and when the parent view is deallocated enumerate alertViews array and assign the delegate to nil. This will ensure that the touch event is ignored and app will function.
// ARC world
#property (strong, nonatomic) NSMutableArray *alertViews;
- (void)dealloc
{
[self.alertViews makeObjectsPerformSelector:#selector(setDelegate:) withObject:nil];
}
Make sure you are implementing the UIAlertViewDelegate protocol.
If you don't care about when the alert is dismissed just init with delegate as nil.
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"test" message:#"test" delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];