Question

问题是：有动作（触摸内部按钮）我将对象保存到核心数据，如果一切正常，则解除控制器。但是控制器并没有解雇，我的代表也没有工作。我试图调试并发现信息有效并且保存，但委托和解雇不是因为未知原因。

这是代码：动作：

- (IBAction)acceptDayOfWeek:(id)sender
{
    managedObjectContext = [AppDelegate sharedDelegate].managedObjectContext;

    int selectedString = [dayOfWeekPicker selectedRowInComponent:0];
    NSDate *weekDayUnknwn = [days objectAtIndex:selectedString];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"EEEE"];
    weekDayForSave = [dateFormatter stringFromDate:weekDayUnknwn];

    ReadySubject *readySubject = [NSEntityDescription insertNewObjectForEntityForName:@"ReadySubject" inManagedObjectContext:self.managedObjectContext];
    readySubject.dayOfWeek = weekDayForSave;


    NSError *error;
    if ([managedObjectContext save:&error])
    {
        [self.delegate changeWeekDay];
        [self dismissViewControllerAnimated:YES completion:nil];
    }
    else
    {
        NSLog(@"%@", [error localizedDescription]);
    }

}

委托

#pragma mark ChangeDayOfWeekDelegate

- (void) changeWeekDay
{
    [dateLabel setNeedsDisplay];
    [self makingArrayOfWeekDays];
}

在代表中实现的方法

- (NSArray *)takeDayOfWeekFromCoreData
{
    managedObjectContext = [AppDelegate sharedDelegate].managedObjectContext;

    NSFetchRequest *request = [[NSFetchRequest alloc]init];

    NSEntityDescription *description = [NSEntityDescription entityForName:@"ReadySubject" inManagedObjectContext:managedObjectContext];
    [request setEntity:description];

    NSError *requestError = nil;

    dayOfWeekArray = [[self.managedObjectContext executeFetchRequest:request error:&requestError] mutableCopy];

    if (requestError) {
        NSLog(@"%@" , [requestError localizedDescription]);
    }
    return dayOfWeekArray;

}

- (void)makingArrayOfWeekDays
{
    [self takeDayOfWeekFromCoreData];
    dayOfWeekIndexesArray = [dayOfWeekArray valueForKey:@"dayOfWeek"];
    if ([dayOfWeekIndexesArray count] != 0) {
        NSLog(@"%@", [dayOfWeekIndexesArray objectAtIndex:0]);
    }
}

设置委托

@protocol ChangeDayOfWeekDelegate

- (void) changeWeekDay;

@end

@interface ChageDayOfWeekViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDelegate>

@property (strong, nonatomic) id <ChangeDayOfWeekDelegate> delegate;

和

#import "ChageDayOfWeekViewController.h"

@interface ScheduleViewController : UIViewController <UITableViewDataSource, UITableViewDelegate, UIAlertViewDelegate, MakingEventViewControllerDelegate, ChangeDayOfWeekDelegate>

Answer 1

pbasdf说的是，如果代码没有执行，委托可能是nil。要检查这一点，您可以更改操作中的代码，如下所示，然后发布结果。

if ([managedObjectContext save:&error])
{
    if (self.delegate) {
        NSLog(@"delegate is set");
        [self.delegate changeWeekDay];
    } else {
        NSLog(@"delegate is not set and can not execute code");
    }            
    NSLog(@"If I reach this part of code and I am the ViewController I should be dismissed");
    [self dismissViewControllerAnimated:YES completion:nil];
}

如果这不是我不得不说你的代码片段令人恼火的原因，因为你无法看到什么属于什么，你应该总是将文件名发布在顶部。

委托和方法没有理由不执行

1 个答案: