按下 UIAlerView 按钮后方法没有响应

Question

我遇到这个问题，我显示警报视图，然后按下按钮后某些方法应该运行，但两者都不会。

- (void)insertNewObject //Works fine
{
//AlertView is a subclass of UIAlertView I created.
    AlertView *al = [AlertView alloc];
    al = [al initWithTitle:@"title" message:@"message" delegate:[self view] cancelButtonTitle:@"cencel" okButtonTitle:@"ok"];
    [al.titlebox becomeFirstResponder];

    //[view setAlertViewStyle:UIAlertViewStylePlainTextInput];
    [al show];
} /Till here everything works fine.

下面的所有代码都不起作用。或者它们起作用了，我只是不知道，因为它们不运行。

//This method does no run al all.
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex2
{

    if(buttonIndex2 == 0)
    {
        _buttonIndex = buttonIndex2;
        [self showAbortAlert];

    } else 
    {
    _buttonIndex = buttonIndex2;
        [self addObject];
    }
}

- (void)addObject 
{
    if(_buttonIndex == 1) {
        // Create a new instance of the entity managed by the fetched results controller.
        NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
        NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
        NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];

    // If appropriate, configure the new managed object.
    // Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
    [newManagedObject setValue:[NSDate date] forKey:@"timeStamp"];
    //[newManagedObject setValue:<#(id)#> forKey:<#(NSString *)#>];
    //[newManagedObject setValue:<#(id)#> forKey:<#(NSString *)#>];

    // Save the context.
        NSError *error = nil;
        if (![context save:&error]) {
            /*
             Replace this implementation with code to handle the error appropriately.

             abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
             */
            NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
            abort();
        }
    } else {
        [self showAbortAlert];
    }
}

- (void)showAbortAlert
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Action Aborted" message:nil delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    [alert setAlertViewStyle:UIAlertViewStyleDefault];
    [alert show];
}

没有编译错误。 提前致谢！

Answer 1

我不知道这是否可以解决您所有的问题，但是在您给出的代码示例中，当您希望它成为 ViewController 时，您可能会错误地将委托设置为视图：

也就是说，而不是：

al = [al initWithTitle:@"title" message:@"message" delegate:[self view] cancelButtonTitle:@"cencel" okButtonTitle:@"ok"];

您可能想要这样做：

al = [al initWithTitle:@"title" message:@"message" delegate:self cancelButtonTitle:@"cencel" okButtonTitle:@"ok"];

另外，由于您分配了警报，所以不要忘记在调用 show 后释放它。

//some code here

[al show];
[al release];
}