j'ai une chaîne déclarer en tant que tellecomment mettre à jour une variable de chaîne par une autre chaîne de variable
NSString *str = [[NSString alloc] initWithFormat:@"I require an average GPA of at least %.2f to achieve my Goal of %@ this semester - NTU GPA Calculator", pgagoal,(NSString *)[myPickerDelegate.myGoal objectAtIndex: [myPicker selectedRowInComponent:0]]];
i déclarais une variable globale
NSStrinng *tweetString
et veut copier la chaîne dans str tweetString . comment dois-je le copier? puisque les deux sont des pointeurs, j'ai essayé:
tweetString = str;
ou
tweetString = [NSString stringWithFormat:@"%@", str];
mais il travaille DOEST.
EDIT: mon code:
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex1{
NSLog(@"buttonindex 1 clicked");
NSString *str2;
NSLog(@"tweetString before if: %@", tweetString);
if (pgagoal < 0) {
NSString *str2 = [[NSString alloc] initWithFormat:@"Confirm, Guarantee, Chop and Stamp! I can achieve my Goal of %@ this semester - NTU GPA Calculator", (NSString *)[myPickerDelegate.myGoal objectAtIndex: [myPicker selectedRowInComponent:0]]];
NSLog(@"tweetString: < 0 %@", str2);
}
else if (pgagoal > 5){
NSString *str2 = [[NSString alloc] initWithFormat:@"Its impossible!, i need an average GPA of at least %.2f to achieve %@ this semester - NTU GPA Calculator", pgagoal,(NSString *)[myPickerDelegate.myGoal objectAtIndex: [myPicker selectedRowInComponent:0]]];
NSLog(@"tweetString: >5 %@", str2);
}
else{
NSString *str2 = [[NSString alloc] initWithFormat:@"I require an average GPA of at least %.2f to achieve my Goal of %@ this semester - NTU GPA Calculator", pgagoal,(NSString *)[myPickerDelegate.myGoal objectAtIndex: [myPicker selectedRowInComponent:0]]];
NSLog(@"tweetString with else: %@", str2);
}
//did i update tweetString correctly?
tweetString = [NSString stringWithString:str2]; <-- stop working from this point EXC_BAD_ACCESS
NSLog(@"tweetString after if else: %@", tweetString);
[self sendEasyTweet:tweetString];
NSLog(@"tweetString: %@", tweetString);
[str2 release];
}
- (void)sendEasyTweet {
// Set up the built-in twitter composition view controller.
TWTweetComposeViewController *tweetViewController = [[TWTweetComposeViewController alloc] init];
// Set the initial tweet text. See the framework for additional properties that can be set.
[tweetViewController setInitialText:tweetString];
// Create the completion handler block.
[tweetViewController setCompletionHandler:^(TWTweetComposeViewControllerResult result) {
switch (result) {
case TWTweetComposeViewControllerResultCancelled:
// The cancel button was tapped.
NSLog(@"Tweet cancelled");
break;
case TWTweetComposeViewControllerResultDone:
// The tweet was sent.
NSLog(@"Tweet done");
break;
default:
break;
}
// Dismiss the tweet composition view controller.
[self dismissModalViewControllerAnimated:YES];
}];
// Present the tweet composition view controller modally.
[self presentModalViewController:tweetViewController animated:YES];
}
EDIT2: sortie Debbuger:
2011-12-29 09:54:22.963 GPA[487:707] buttonindex 1 clicked
2011-12-29 09:54:22.966 GPA[487:707] tweetString before if: NTU GPA Calculator <-- i init the string at viewDidLoad
2011-12-29 09:54:22.968 GPA[487:707] tweetString with else: I require an average GPA of at least 1.56 to achieve my Goal of Third Class Honors this semester - NTU GPA Calculator
(gdb)
EDIT3: mon tweetString est déclarée en vue Controller.h comme
@interface GPAMainViewController : UIViewController <GPAFlipsideViewControllerDelegate>{
UIPickerView * myPicker;
GPAAppDelegate * myPickerDelegate;
IBOutlet UITextField *txtGPA;
IBOutlet UITextField *txtTotalAU;
IBOutlet UITextField *txtRemainingAU;
double pgagoal;
NSString *tweetString;
}
@property (nonatomic, retain) IBOutlet UIPickerView * myPicker;
@property (nonatomic, retain) IBOutlet GPAAppDelegate *myPickerDelegate;
@property (nonatomic, retain) UITextField *txtGPA;
@property (nonatomic, retain) UITextField *txtTotalAU;
@property (nonatomic, retain) UITextField *txtRemainingAU;
@property (nonatomic, retain) NSString *tweetString;
-(IBAction)finishEditing:(id)sender;
-(IBAction)calculateGoal: (id) sender;
-(IBAction)showInfo:(id)sender;
-(IBAction)nextField:(id)sender;
-(IBAction)resetField:(id)sender;
-(void)sendEasyTweet:(id)sender;
Les deux affectations devraient fonctionner. En quoi cela ne fonctionne-t-il pas? compiler l'erreur? –
Salut Mattias, j'ai le poste avec un segment de mon code, plus l'erreur que j'ai reçu .. – at0m87
C'est des devoirs, oui? –