I have searched and searched the board(s) and am not able to figure this out. It has got to be something simple and right in front of me.
I am trying clean up my code and make it more reusable. I was taking some UIActionSheet code that works from a UIViewController and making its own object file. Works fine, until I add UIActionSheetDelegate methods.
When a button is pressed, instead of firing the actionSheetCancel method, it crashes with no stack trace. Every time.
My code is below. Any help would be appreciated. My guess has been it is because I am not using the xcode storyboard tool to connect things together, but I would think this is legal.
egcTestSheet.h:
#import <UIKit/UIKit.h>
#interface egcTestSheet : NSObject <UIActionSheetDelegate> {
}
- (void) showSheet:(UITabBar *) tabBar
displayTitle:(NSString *) name;
#end
egcTestSheet.m
#import "egcTestSheet.h"
#implementation egcTestSheet
-(void) showSheet:(UITabBar *)tabBar displayTitle:(NSString *)name{
UIActionSheet *menu = [[UIActionSheet alloc] initWithTitle:name
delegate:self
cancelButtonTitle:#"Done"
destructiveButtonTitle:#"Cancel"otherButtonTitles:nil];
[menu showFromTabBar:tabBar];
[menu setBounds:CGRectMake(0,0,320, 700)];
}
// actionsheet delegate protocol item
- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex: (NSInteger)buttonIndex{
NSLog(#"button index = %d", buttonIndex);
}
- (void)actionSheetCancel:(UIActionSheet *)actionSheet{
NSLog(#"in action canceled method");
}
#end
call code from a UIViewController object:
egcTestSheet *sheet = [[egcTestSheet alloc] init];
[sheet showSheet:self.tabBarController.tabBar displayTitle:#"new test"];
Your action sheet is probably being released as it is dismissed (are you using ARC?). This means when it tries to call it's delegate to inform said delegate of its dismissal/selection, it is trying to call self. Self is a dangling pointer by this time, because it has been released.
In the view controller that is presenting/calling this action sheet, set a property to keep a reference to the action sheet. Set the property to nil on dismissal of the action sheet.
Related
.h
IBOutlet UIWebView *webview;
.m
- (void)viewDidLoad {
[webview loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://blabla.com"]]];
}
- (void)webView:(UIWebView *)webViewfail didFailLoadWithError:(NSError *)error {
if([webViewfail isEqual:webview]) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Connection Failed"
message:#"Check your Internet connection before refreshing."
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
}
}
I do not know what I did wrong, I tried making it appear but setting off internet connection. Any tips or suggestions will be helpful.
Make sure you have hooked up the delegate in interface builder (if that is what you are using). You can do this by selecting the web view, and drag (while holding control) to the view controller / file's owner, and then select delegate (which pops up when you release the mouse).
Or you can hook up your delegate in code in your viewDidLoad method like so:
[webView setDelegate:self]
Make sure your view controller conforms to the UIWebViewDelegate protocol by adding in your .h
#interface MyViewController : UIViewController <UIWebViewDelegate>
Good luck :)
Check this:
Make sure the object containing the quoted method is indeed the web view's delegate.
Give the web view's url request a really short timeoutInterval.
Try this also:
In your ViewController.h
#interface ViewController : UIViewController <UIWebViewDelegate>
And in ViewController.m below [super viewDidLoad] add :
self.webView.Delegate = self;
I know the ARC in iOS 5 but I'm now developing pre-iOS 5 code style, and want to solve this problem by a manual release approach.
My only goal for this is to make a very handy custom alert view with UITextField.
I have a 'BigView' view that has many functions in it. And it can possibly generate many UIAlertView for many different situation on the display with that view. So I know the way use UIAlertViewDelegate for each alert view, but kind of experimentally try want to make this as like UIButton's 'addTarget'(actually it's UIControl's method).
Briefly,
This is in the part of 'BigView' class and my 'TextAlert' instance fired by a button for email gathering .
BigView.m
- (void)emailFeedback:(id)sender
{
TextAlert *textAlert = [[TextAlert alloc] initWithTitle:#"Enter your email address"];
[textAlert setTarget:self action:#selector(textAlertInputed:)];
// [textAlert release];
}
- (void)textAlertInputed:(NSString *)text
{
NSLog(#"text alert inputed, text: %#", text);
}
and these are full my TextAlert files.
TextAlert.h
#import <Foundation/Foundation.h>
#interface TextAlert : NSObject <UIAlertViewDelegate>
{
UIAlertView *alertView;
UITextField *textField;
id target;
SEL action;
}
- (id)initWithTitle:(NSString *)title;
- (void)setTarget:(id)target action:(SEL)action;
#end
TextAlert.m
#import "TextAlert.h"
#implementation TextAlert
- (id)initWithTitle:(NSString *)title
{
if (self = [super init])
{
alertView = [[UIAlertView alloc] initWithTitle:title message:#"beneath" delegate:self cancelButtonTitle:#"Cancel" otherButtonTitles:#"OK", nil];
textField = [[UITextField alloc] initWithFrame:CGRectMake(12, 45, 260, 25)];
CGAffineTransform myTransform = CGAffineTransformMakeTranslation(0, 60);
[alertView setTransform:myTransform];
[textField setBackgroundColor:[UIColor whiteColor]];
[alertView addSubview:textField];
[alertView show];
}
return self;
}
- (void)dealloc
{
[alertView release]; alertView = nil;
[textField release]; textField = nil;
[super dealloc];
}
- (void)setTarget:(id)_target action:(SEL)_action
{
target = _target;
action = _action;
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
[target performSelector:action withObject:textField.text];
}
#end
So my main problem is the releasing point of TextAlert instance in the 'BigView' as you can see the only comment part full codes above. Of course if I remove that comment out, I got crash for call for method of deallocated.
And I also get error make textAlert instance as autoreleased one.
For me, the only solution for this is to make the 'textAlert' object in the 'BigView' a member of 'BigView' not local object. But in that case, my initial goal for handy and lightweight approach for this is not satisfied, I think. And the 'BigView' has already many member instances so I don't want to add any more.
So any suggestions? Or It will be welcome any comment for this trying. I'm ready to hear any
reproves to my insufficient code, really.
Thanks in advance,
MK
If everything works except your release problem you should only consider implementing public "show" method and private "dismiss" method (in your custom alert view).. In show method you should call [self retain] beside other things and on dismiss (add this target to button or whatever dismisses your view) call [self relese].
This isn't directly what you asked for, but could help you anyway.
Handling multiple UIAlertViews in a single UIViewController can be painful. When I ran into this problem, I found an alternative control on github, called BlockAlertsAndActionSheets. It uses blocks instead of delegates, the appearance can be fully customized (even to the default Apple-style) and there is also an "AlertView with an UITextField". Works good for me and I didn't have to reinvent that wheel! ;-)
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];
});
Hi there I currently I have a warning on a line of code where I am trying to push a new view onto the screen.
Outline // my NSObject receives a code=1 from my server I have set up. Everything works fine the code comes through which then initializes an AlertView where I have set up an if statement to catch the button click of my AlertView message. When that button is pressed my application falls over.
I have declared my ViewController of the view I am trying to push in its header file and there are no errors just the warning when compiled.
this is my NSObject I have made
/////.h
#import <Foundation/Foundation.h>
#interface alerts : NSObject {
}
- (void)pleaseRegisterDevice;
#end
/////.m
#import "alerts.h"
#import "instaCode1_3AppDelegate.h"
#import "RegisterDeviceViewController.h"
#implementation alerts
//use this alert when phone falls out of sync
- (void)pleaseRegisterDevice {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Please Register Device"
message:#"click OK to register"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert autorelease];
[alert show];
}
//Catch pleaseRegisterDevice method
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
NSString *buttonTitle=[alertView buttonTitleAtIndex:buttonIndex];
if ([buttonTitle isEqualToString:#"OK"]) {
NSLog(#"msg from alertView method");
//open new wndow
RegisterDeviceViewController *regViewController = [[RegisterDeviceViewController alloc] init];
//Push it onto the top pf the navigation controller's stack
**[[self navigationController] pushViewController:regViewController animated:YES];**
}
else {
NSLog(#"was not able to push view");
}
}
- (void)dealloc {
[super dealloc];
}
#end
I have bolded the line of code where I get the warning 'alerts' may not respond to -navigationController
any help would be greatly appreciated.
I dont think an NSObject subclass has a UINavigationController...
You need to get a pointer to your app delegate's navigation controller like so
MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.navigationController pushViewController:regViewController animated:YES];
navigationController is a property defined on a UIViewController. A NSObject does not have this method.
You don't have any instance member or method called navigationController, hence the warning.
I've a viewcontroller "ResultsViewController" with a button called emailbutton. when this button is pressed, i want a function to be called from another view called "Illusions_AppViewController" (both these viewcontrollers are not linked).
Therefore i defined a protocol in the "ResultsViewController.h":
#protocol ResultsViewDelegate <NSObject>
#optional
- (void) resultspage;
#end
#interface ResultsViewController : UIViewController
{
id<ResultsViewDelegate> mydelegate;
UIButton *emailButton;
}
#property(nonatomic,retain) IBOutlet UIButton *emailButton;
#property (nonatomic,assign) id<ResultsViewDelegate> mydelegate;
#end
In the ResultsViewController.m :
-(IBAction)emailButtonPressed:(id)sender
{
NSLog(#"entered emailbuttonpressed");// the app enters this method and gets hanged
if ([mydelegate respondsToSelector:#selector(resultspage)]) {
NSLog(#"entered respondstoselector");// this is never displayed in the log-showing that the delegates doesnt respond to selector
[mydelegate resultspage];
}
}
In my other view, "Illusions_AppViewController.m":
- (void)resultspage{
NSLog(#"Entered results page");
ResultsPageController *resultspagecontroller = [[ResultsPageController alloc] initWithNibName:#"ResultsPageController" bundle:nil];
resultspagecontroller.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:resultspagecontroller animated:YES];
}
Would appreciate if anyone can help me with this. I've no clue of why the delegate is not called. the app gets hanged as soon as i press the emailbutton. Thanks!
The implementation/use of delegates is wrong. Please refer to this tutorial.
Hope this helps.
Thanks,
Madhup
or is there any other way to get this done. i just need the results page function to be called whenever the email button is pressed. i tried using this way:
ResultsViewController.m
-(IBAction)emailButtonPressed:(id)sender
{
NSLog(#"entered emailbuttonpressed");
illusions_AppViewController *illusionsview = [[illusions_AppViewController alloc]init];
[illusionsview performSelector:#selector(resultspage)];
}
Now the results page function gets called, but the resultspagecontroller that it needs to display as a modalviewcontroller never appears.the app hangs, and no errors in the console either.
To answer your second question, you are on the right track. Simply create an instance of your Illusions_AppViewController and call the illusionsView method in it instead using:
- (IBAction)emailButtonPressed {
illusions_AppViewController *illusionsview = [[illusions_AppViewController alloc]init];
[illusionsview resultspage];
[illusionsview release];
}