I create a class to call UIAlertview show on my screen. I write the UIAlert function in another class. Both these two classes are not my viewController class.
I use this UIAlert, which is a UITextfield inside, to store texts into a plist file.
here is the class to call UIAlert:
#import "Story.h"
#implementation Story
...
+ (void)stage1
{
AlertClass *pointer = [AlertClass new];
[pointer doAlert];
}
here is the class AlertClass.m file:
- (void)doAlert
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Title" message:#"Message" delegate:self cancelButtonTitle:#"Done" otherButtonTitles:nil];
alert.alertViewStyle = UIAlertViewStylePlainTextInput;
[alert show];
}
//this makes crash!
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
self.storyFlow.text = [alertView textFieldAtIndex:0].text;
}
Before I add UIAlertViewDelegate in the .h and override the method "clickedButtonAtIndex", it works great. However, I need to store some data from the UITextfield inside the alert view. I get crash and don't know the message it responds as following.
Please help me to solve this problem. Thanks.
[crash pic] https://dl.dropbox.com/u/47381923/crash.tiff
do an NSLog on the text you get back from the Alert View to see whether that is the crash or the subsequent 'self.storyFlow.text = ' is causing it. Perhaps self.storyFlow has not been created yet (with alloc/init)
Related
I am a newbie in objective c;
I am getting an error at creating a UIAlertview instantiation statements (UIAlert * myAlert, they are in separate scopes)
I have referred the following stackoverflow entries such as This, this, this too and much more research over the internet.
I am unable to get a break through
Following are my alert calls
This is my view controller code where I have put up the "UIAlertViewDelegate"
#import <UIKit/UIKit.h>
#interface gameFirstViewController : UIViewController<UIAlertViewDelegate>
#end
This is my class declaration
#import <Foundation/Foundation.h>
#interface GameLogic : UIView
//all sorts of various non relevant property declarations
#end
Here is my implementation for the alerts
//action to take when an alert is shown
- (void)alertView:(UIAlertView *)alertView
didDismissWithButtonIndex:(NSInteger) buttonIndex
{ NSLog(#"OK Tapped");
NSUserDefaults *MySettingsData = [NSUserDefaults standardUserDefaults];
row= [MySettingsData integerForKey:#"Row_count"];
col = [MySettingsData integerForKey:#"Column_count"];
if(buttonIndex==0)
{
for(int i=0;i<row;++i)
{
for(int j=0;j<col;++j)
{
myarr[i][j]=0;
}
}
if(_TimerStatus ==1)
{
[mainTimer invalidate];
mainTimer=nil;
_TimerStatus=0;
}
[self super_reset];
[self setNeedsDisplay];
NSLog(#"Game reset");
return;
}
}
//my usage of the alerts at 2 different places
UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle: #"GAME OVER"
message:#"You clicked on a mine, tap on ok to reset"
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil, nil];
[myAlert performSelectorOnMainThread:#selector(show)
withObject:nil
waitUntilDone:YES];
UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle: #"You Won! Whoo Hoo"
message:#"You have successfully dodged every minefield"
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil, nil];
[myAlert performSelectorOnMainThread:#selector(show)
withObject:nil
waitUntilDone:YES];
I am not sure where I am going wrong, any help would be great!
Thanks.
The way you are creating the UIAlertView is not safe in ARC. It's fine if you use the object right away, but you're passing it the performSelectorOnMainThread method. ARC may dealloc your myAlert variable by the time the main thread gets to perform the selector. That's likely why you're seeing the EXC_Bad_Request.
Either make myAlert a strong property, so it survives, or delay the creation of the UIAlert until the main thread is able to call the show method. You can do that like this:
dispatch_async(dispatch_get_main_queue(), ^{
[[[UIAlertView alloc] initWithTitle:#"GAME OVER" message:#"You clicked on a mine, tap on ok to reset" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil] show];
});
Note: I removed your double nil for the titles. I don't think that would make a difference, but just in case.
#import <UIKit/UIAlertView.h>
#class NSObject;
#interface SBIconController : NSObject
+ (SBIconController *)sharedInstance;
- (BOOL)isEditing;
#end
%hook SBIconController
-(void)iconTapped:(id)tapped {
SBIconController *sbic = [objc_getClass("SBIconController") sharedInstance];
if ([sbic isEditing]) {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Message" message:[NSString stringWithFormat:#"%#", tapped] delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alertView show];
[alertView release];
}
%orig;
}
%end
Above is a simple tweak that I have created with Logos. For some reason after installing, nothing is working, I just can't figure out what the problem is and How can I solve this problem?
Other questions that I have are:
Why do we declare class like SBIconController when there's already a SBIconController class?
Why do we declare it as a subclass of NSObject?
Why don't we just type in SBIconController when we're calling the [SBIconController sharedInstance] instead of [objc_getClass("SBIconController") sharedInstance]?
Thanks a lot for your help!
The code is fine. I tested it (I don't use logos) and iconTapped: method is indeed called when you tap an app icon. But what are you trying to achieve with isEditing? This property indicates whether you are editing SpringBoard (tap and hold an app icon) and when it equals YES method iconTapped: is NOT called when icon is tapped. It's called only when isEditing equals NO. So I suggest you insert alert without if ([sbic isEditing]) to test whether your tweak is working.
As for your other questions:
When dealing with private APIs we don't have headers and will get warnings/errors if we try to use them. In your case it's SBIconController. To solve this problem we can either download headers that others dumped using various tools like class-dump or declare these private APIs yourself. In your case it's latter.
Because SBIconController inherits from NSObject.
You can do it either way. Of course, when you have class declaration you don't need to use objc_getClass. And in your case you don't even need either of this things. You can just use self like you would in any other obj-C method. Your code will look like this:
%hook SBIconController
-(void)iconTapped:(id)tapped {
if ([self isEditing]) {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Message" message:[NSString stringWithFormat:#"%#", tapped] delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alertView show];
[alertView release];
}
%orig;
}
%end
How do you pass a variable to the UIAlertView delegate?
I have a variable that I want to use in the alert view delegate. It is only used in the function that shows the UIAlertView and the UIAlertView delegate, so i don't think it should be a property on the controller. Is there a way to attach the variable to UIAlertView and retrieve it in the delegate?
- (void) someUserCondition:(SOCode *)userCode {
if ([userCode warrentsConfirmation] > 0) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Title" message:#"Are you sure?" delegate:self cancelButtonTitle:#"Cancel" otherButtonTitles:#"OK",nil];
[alert setAlertViewStyle:UIAlertViewStyleDefault];
//TODO somehow store the code variable on the alert view
[alert show];
}
}
- (void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
NSString *title = [alertView buttonTitleAtIndex:buttonIndex];
if ([title isEqualToString:#"OK"]){
SOCode *userCode = //TODO somehow get the code from the alert view
[self continueWithCode:code];
}
}
in .h before interface:
extern const char MyConstantKey;
#interface ViewController...
in .m import:
import <objc/runtime.h>
in .m before implementation
const char MyConstantKey;
in .m implementation
-(void)viewDidAppear:(BOOL)animated{ //or wherever
NSString *aString = #"This is a string";
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Testing" message:#"test is test" delegate:self cancelButtonTitle:#"Okay" otherButtonTitles:nil];
[alert show];
[alert release];
objc_setAssociatedObject(alert, &MyConstantKey, aString, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
in .m alertview callback
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
NSString *associatedString = objc_getAssociatedObject(alertView, &MyConstantKey);
NSLog(#"associated string: %#", associatedString);
}
Use Associated Objects. It is described in more detail here: Your New Friends: Obj-C Associated Objects
To set the object you use use:
objc_setAssociatedObject(alert, &key, userCode, OBJC_ASSOCIATION_RETAIN);
And then to get it back:
SOCode *userCode = objc_getAssociatedObject(alertView, &key);
You also need to add static char key; so that it is in the scope of moth methods.
Update
I have wrapped this into a category on UIAlertView. You can use Cocoapods to bring it in:
pod 'HCViews/UIAlertViewHCContext', '~> 1.2'
The source is available here: https://github.com/hypercrypt/HCViews/blob/master/Categories/UIAlertView%2BHCContext.h
A lot of posts talk about the concepts behind associated objects (which is good!) but sometimes you just want to see the code. Here's a clean and quick category that you can either put in a separate file or above the interface of one of your existing .m files (you could even replace UIAlertView with NSObject and effectively add a context property to any object):
#import <objc/runtime.h>
#interface UIAlertView (Private)
#property (nonatomic, strong) id context;
#end
#implementation UIAlertView (Private)
#dynamic context;
-(void)setContext:(id)context {
objc_setAssociatedObject(self, #selector(context), context, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
-(id)context {
return objc_getAssociatedObject(self, #selector(context));
}
#end
And then you'll be able to do something like:
NSObject *myObject = [NSObject new];
UIAlertView *alertView = ...
alertView.context = myObject;
IMPORTANT:
And don't forget to nil the context in dealloc!!
UIAlertView is a subclass of UIView which has a tag property you can set to an integer. Unfortunately if you need something other than an integer to identify/pass info to the delegate than you will need to set some properties (or set up an array with the tag indexing into it) on the delegate itself. Advaith's way will probably work but is technically not supported by Apple.
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Title" message:#"Are you sure?" delegate:self cancelButtonTitle:#"Cancel" otherButtonTitles:#"OK",nil];
[alert setAlertViewStyle:UIAlertViewStyleDefault];
alert.tag = SOMEINTEGER;
[alert show];
I suspect the most straight-forward way is a property in the alert view's delegate class. An alert view doesn't have any provision for "user info" and doesn't support sub-classing, which removes the only shortcuts that come to mind.
Subclass UIAlertView, add a property called userInfo with type of your choice. Set the user info value at the time you create an instance of Subclassed UIAlertView, and retrieve it from within the delegate method. (There you will get the subclassed instance which holds the userInfo)
Can someone help me with implementing this code into a view based app?
This is the code that I have:
- (void)webViewUIWebView *)newsweb didFailLoadWithErrorNSError *)error {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Connection Error1!" message:#"Please confirm network connectivity and try again!" delegate:self cancelButtonTitle:#"Dismiss" otherButtonTitles:nil];
[alert show];
[alert release];
}
With this code and any other code that I may need, but don't know, I would like to know what code to implement into the .h + .m view controller files.
What I am trying to achieve is an error after starting the app if there is no network connection available. What I'm worried about also but not quite sure if it will happen, is that this will repeat the error "x" times for how many UIViews I have. If that would be the case could you also help me should that it would only show the error once.
Put a Boolean in your header file, and when the alert fires, change it. If the Boolean is false, then simply don't show the alert.
#interface
BOOL alertShown;
#end
#implementation
-(void)applicationDidFinishLaunching{
alertShown = NO;
}
-(void)webViewError{
if(alertShown == NO){
//show the alert
alertShown = YES;
}
}
#end
I have a question about showing an alert on the screen. The thing is: I have an app with 20 to 30 different screens (nibs) And in each nib I do some checking to see if the user has inserted text in a textedit. And some alert messages are identical to others. Like In 3 nibs there is a text field for the user to enter his age, and the an alert that shows up if he left it blank.
What i want to do is to create a method to show these alerts so I don`t need to have the same alert on different nibs. instead of calling an alert view in each nib, I would call the method and pass what kind of alertview to pop up.
What would be the best way to implement this method?
TIA.
You can just alloc init a new UIAlertView as usual but you have to remember to pass the delegate in.
Here is my method:
- (UIAlertView *)getUIAlertViewWithDelegate:(id)delegate title:(NSString *)title cancelTitle:(NSString *)cancel {
return [[[UIAlertView alloc] initWithTitle:title delegate:delegate cancelButtonTitle:cancel otherButtonTitles:nil] autorelease];
}
All right, I managed to do it. Thanks to all that helped. This is my final solution
I created a common.m classs for some methods that I use in various nibs.
Common.h
#interface MetodosGerais : NSObject <UIAlertViewDelegate>{...}
- (void)getUIAlertViewWithDelegate:(id)delegate title:(NSString *)title cancelTitle:(NSString *)cancel;
Common.m
- (void)getUIAlertViewWithDelegate:(id)delegate title:(NSString *)title cancelTitle:(NSString *)cancel {
if (title == #"Enter your Height"){
[[[[UIAlertView alloc] initWithTitle:NSLocalizedString(#"Atention!", #"Atenção!")
message:#"You Should enter Your Height."
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] autorelease] show];
}
else if (title == #"Enter your Age"){
[[[[UIAlertView alloc] initWithTitle:NSLocalizedString(#"Atention!", #"Atenção!")
message:#"You Should enter your Age."
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] autorelease] show];
}
...
and in my classes that I want to use it I did
Common *myAlert = (Common *)[[UIApplication sharedApplication] delegate];
if ([idade.text length] == 0) {
[myAlert getUIAlertViewWithDelegate:self title:#"Enter Your Age" cancelTitle:#"OK"];
}...