Executing a snippet of code in the AlertView OK button declaration - iphone

in my Alert View, there is two button, OK and Cancel. When the user click the OK button, the delegate method dismissWithClickedButtonIndex:animated get called, and if the index is 0, then i get called to a method to execute some code:
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Alert"
message:#"Are you sure you want to exit"
delegate:self cancelButtonTitle: #"OK"
otherButtonTitles: #"Cancel",nil];
[alert show];
[alert release];//release the reference
Delegate method:
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex{
if (buttonIndex==0) {
[self aMethod];
}
}
-(void)aMethod{
//Some useful code
}
Now, what i want to instead of all this, is to execute the code of the aMethod method in the AlertView directly, without referring to A delegate method and a method which get called, something like that:
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Alert"
message:#"Are you sure you want to exit"
delegate:self cancelButtonTitle: #"OK" //Put here some useful code
otherButtonTitles: #"Cancel",nil];
Is it possible?

Unfortunately this is not possible at this time (iOS 5.1). The AlertView class does not support blocks.

I made a pair of UIAlertView and UIActionSheet subclasses that do exactly that. Grab them here:
https://github.com/rydermackay/RMActionSheet
Use them like this:
RMAlertView *alertView = [RMAlertView alertViewWithTitle:#"Alert!" message:nil];
[alertView addButtonWithTitle:#"OK"
action:^{
NSLog(#"OK");
}];
[alertView addCancelButtonWithTitle:#"Cancel"
action:nil];
[alertView show];
EDIT:
From your comments it sounds like you're not familiar with blocks. Read this now. Seriously.
http://developer.apple.com/library/ios/#documentation/cocoa/Conceptual/Blocks/Articles/00_Introduction.html
This is a good one too:
http://www.mikeash.com/pyblog/friday-qa-2009-08-14-practical-blocks.html

Related

Why is app crashing when showing UIAlertView?

I've implemented the Reachability function in a method that handles all the server requests. I can see through NSLogs that the function works perfectly. However there is never a "pause" within the method which means I can't use the UIAlertView without crashing the program.
I might be going at this the completely wrong way, but I can't find anything else...
Does anybody have an idea of how to get a notification to show somehow?
Thanks in advance
CODE:
-(id) getJson:(NSString *)stringurl{
Reachability * reach = [Reachability reachabilityWithHostname:#"www.google.com"];
NSLog(#"reached %d", reach.isReachable);
if (reach.isReachable == NO) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Passwords don't match."
message:#"The passwords did not match. Please try again."
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
}else{
id x =[self getJsonFromHttp:stringurl];
return x;
}
return nil;
}
After moving the discussion to a chat, we discovered that your UIAlertView was being called from a background thread. Never do anything related to updating the UI (User-Interface) in a background thread. The UIAlertView updates the UI by adding a little pop-up dialog, so it should be done on the main thread. Fix by making these changes:
// (1) Create a new method in your .m/.h and move your UIAlertView code to it
-(void)showMyAlert{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Passwords don't match."
message:#"The passwords did not match. Please try again."
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
}
// (2) In -(id)getJson replace your original UI-related code with a call to your new method
[self performSelectorOnMainThread:#selector(showMyAlert)
withObject:nil
waitUntilDone:YES];

UIAlertViewDelegate not acting as expected

I have a very simple process running where after each round of a simple game the scores are calculated, labels updated and all the normal, very simple stuff. I have a UIAlertView that informs the player of how s/he performed. I use a UIAlertViewDelegate to postpone all the updates, resetting of controls etc. till after the UIAlertView is dismissed. The methods are [startNewRound],[startOver] and [updateLabels]. It's fairly obvious what they all do. Anyway, when the user hits round ten, I've made another UIAlertView that informs the player that the game has ended and shows the overall score. Again, I hoped to use a delegate to postpone the resets till after the AlertView is dismissed. The only problem is, with the endGame AlertView, it seems to be using the first AlertView's delegate method causing the game to continue with a new round and not start from the beginning. I hope this makes sense. Anyway, here are snippets of my code.
if (round == 10){
UIAlertView *endGame = [[UIAlertView alloc]
initWithTitle: #"End of Game"
message: endMessage
delegate:self
cancelButtonTitle:#"New Game"
otherButtonTitles:nil];
[endGame show];
}
else {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle: title
message: message
delegate:self
cancelButtonTitle:#"Next"
otherButtonTitles:nil];
[alertView show];
}
And then the delegate methods:
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
[self startNewRound];
[self updateLabels];
}
- (void)endGame:(UIAlertView *)endGame didDismissWithButtonIndex:(NSInteger)buttonIndex
{
[self startOver];
}
So there it is. As I mentioned, the endGame AlertView appears to be using alertView's delegate, thus not activating the [self startOver] method. All the methods are working, it's just the AlertView is using the incorrect delegate method. Regards, Mike
Change your code like this,
if (round == 10){
UIAlertView *endGame = [[UIAlertView alloc]
initWithTitle: #"End of Game"
message: endMessage
delegate:self
cancelButtonTitle:#"New Game"
otherButtonTitles:nil];
endGame.tag = 111;
[endGame show];
}
else {
UIAlertView *alertView = [[UIAlertView alloc]
initWithTitle: title
message: message
delegate:self
cancelButtonTitle:#"Next"
otherButtonTitles:nil];
alertView.tag = 222;
[alertView show];
}
and delegate method as,
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
if(alertView.tag == 111)
{
[self startNewRound];
[self updateLabels];
}
else if(alertView.tag == 222)
{
[self startOver];
}
}
You cant have two delegate method for dismisswithbuttonindex, you need to handle this situation with tag.
Give both alert view a different tag and check it on delegate object. Thus you can differentiat the both alert view.

dismissing a UIAlertView programmatically

I need help on dismissing a UIAlertView programmatically. Currently I have this
UIAlertView *alert1 = [[UIAlertView alloc]initWithTitle:#"title" message:#"message" delegate:nil cancelButtonTitle:nil otherButtonTitles:nil];
then later on I call this
[alert1 dismissWithClickedButtonIndex:0 animated:NO];
but nothing happens.
You need to set two things.
1. include your .h file : <UIAlertViewDelegate>
2. please follow below implementation...
UIAlertView *alert1 = [[UIAlertView alloc]initWithTitle:#"title" message:#"message" delegate:nil cancelButtonTitle:nil otherButtonTitles:nil];
[alert1 show];
[self performSelector:#selector(dismiss:) withObject:alert1 afterDelay:1.0];
the dismiss method will be...
-(void)dismiss:(UIAlertView*)alert
{
[alert dismissWithClickedButtonIndex:0 animated:YES];
}
I hope this will help you.
I encountered this problem too.
In my case, for some reason calling:
[alert dismissWithClickedButtonIndex:0 animated:NO];
didn't work always (yes, even calling it on UI thread and yes, alert != nil), instead simply setting the animated flag to YES it worked:
[alert dismissWithClickedButtonIndex:0 animated:YES];
Maybe it's an Apple bug...
you should display it first:
UIAlertView *alert1 = [[UIAlertView alloc]initWithTitle:#"title" message:#"message" delegate:self cancelButtonTitle:#"Cancel" otherButtonTitles:nil];
[alert1 show];
then in delegate method
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex{
if(buttonIndex==0){
// do something
}
}
The methods you called is correct.
I guess the alert1 is nil when your call the method dismissWithClickedButtonIndex:animated:
Try to check your variable alert1.
You can use the delegate method -alertView:didDismissWithButtonIndex: instead—it gets called once the alert view’s been removed from the screen, OR better approach is , use a background thread, e.g. with -performSelectorInBackground:withObject:, to handle whatever processing you need to do.

Multiple alertViews create error

Hello and good afternoon, I'm having some issues here, and to be honest, I don't understand
I have to create different alertViews for the same screen with different messages, most of these alerts only have 1 button, but there's this one to delete that needs 2 buttons, the thing is that, since the others have only 1 button, when I created the 2 button screenview and I added the (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex method, I have some problems
some code here
- (IBAction)saveInfo{
if (med.text.length ==0) {
UIAlertView *alertViewError = [[UIAlertView alloc] initWithTitle:NSLocalizedString(#"ERROR",#"")
message:NSLocalizedString(#"EMPTY1",#"")
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
[alertViewError show];
[alertViewError release];
}
else if(medicamento.text.length >= 41){
[self lenghtError:40:NSLocalizedString(#"TF_MED",#"")];
}
else if (med.text.length ==0 || descripcion.text.length == 0) {
UIAlertView *alertViewError = [[UIAlertView alloc] initWithTitle:NSLocalizedString(#"ERROR",#"")
message:NSLocalizedString(#"EMPTY2",#"")
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
[alertViewError show];
[alertViewError release];
}
else if (descripcion.text.length >= 41){
[self lenghtError:40:NSLocalizedString(#"TF_DESCRIPCION",#"")];
}
else{
[self insertDictionary];
UIAlertView *alertViewAcept = [[UIAlertView alloc] initWithTitle:#""
message: NSLocalizedString(#"ACCEPT_MSG",#"")
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
[alertViewAcept show];
[alertViewAcept release];
[self.navigationController popViewControllerAnimated:YES];
}
}
- (IBAction)cancelData{
UIAlertView *alertViewCancel =
[[UIAlertView alloc] initWithTitle: NSLocalizedString(#"BT_DELETE_MED",#"")
message: NSLocalizedString(#"MSG_DELETE_MED",#"")
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles: #"Cancel", nil];
[alertViewCancel setTag:999];
[alertViewCancel show];
[alertViewCancel release];
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (alertView.tag == 999) {
if(buttonIndex==0){
[self.Bayer_DB_obj deleteRowWithKeyValue:[NSString stringWithFormat:#"%d",IdMed] onKeyName:#"id_ctl_med" onTable:#"ctl_med"];
// code to delete here
[self.navigationController popViewControllerAnimated:YES];
}
}
}
So, in the first part, I created some alerts to indicate the user that he/she is making a mistake, in the second part, I need a confirmation before deletion, but here, I need 2 buttons, then, in the 3rd part, I have the method that is been called, I added a tag to my alert to avoid doing this comparison in all the alerts, the problem is that, when you show alertViewAcept, it takes you to the previous view controller, and after you click the ok button (that actually is the cancelbuttontitle) the app crashes without any "error message"
so I'm not sure what I'm doing wrong, please help
My guess the problem is that you set the delegate for the alertViewAcept, and right after you showed the alert, you pop the viewController and so your delegate will get released, which will then give you an error once a button on the alert view is clicked.
You should do this:
UIAlertView *alertViewAcept = [[UIAlertView alloc] initWithTitle:#""
message: NSLocalizedString(#"ACCEPT_MSG",#"")
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles: nil];
Even better, all your alerts which only have the OK button, do not need a delegate. And in that case you do not even need the tag.

IPHONE: UIAlertView called twice in a custom function/IBAction

i have an IBAction which does some processing and within will have a few UIAlertViews (to show alerts). However it seems that the FIRST alert in the paragraph is being called TWICE (once immediately after i clicked and another time after all the other alerts has occured). Additionally, the first time the alert appears, the alert automatically closes even though i have an OK button and the user has not clicked on it. The 2nd time the alert appears, it will require the user to click on OK.
I tried moving the paragraph out from IBAction into its own function but still the problem occurs.
all the alerts in my IBAction/function are the same:
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"blah" message:#"blah" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil,nil];
[alert show];
[alert release];
but the other alerts function normally.
the code looks like this ("blah" is the one being called twice):
-(void)function {
if (......) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"blah" message:#"blah" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil,nil];
[alert show];
[alert release];
for (int i=0; i<2; i++) {
if (.....) {
//do stuff
} else {
UIAlertView *alert2 = [[UIAlertView alloc] initWithTitle:#"blah2" message:#"blah2" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil,nil];
[alert2 show];
[alert2 release];
}
}
} else {
UIAlertView *alert3 = [[UIAlertView alloc] initWithTitle:#"blah3" message:#"blah3" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil,nil];
[alert3 show];
[alert3 release];
}
}
please help!
First of all, we need more code to diagnose your problem. What you provide is not sufficient.
Second, I once encountered a similar problem: when a compose an email action is triggered by the user who didn't set up her email account on that device, I asked my app to show an UIAlertView. However, when I tested my code on a real device with such a scenario, two consecutive UIAlertViews showed, one after another, both of which are about the email account not set up issue.
I finally figured out that the iOS system will automatically show an UIAlertView when the email account is not set up while a user tries to compose an email, which is why two UIAlertViews showed up when I only expected one.
Hope that helps.