I'm working on an iOS app written in Objective-C and I have table view with many records from Core data. When I delete one record the row is deleted from Core data but the app is giving me an error:
-[_PFArray removeObjectAtIndex:]: unrecognized selector sent to instance 0x7fbf5be5e6b0
I have tried many times to change this but it still crashes the app or the table view is not updated after deletion.
This is my header file:
#import <UIKit/UIKit.h>
#include "Notes.h"
@interface ShowClassNote : UIViewController<UITabBarDelegate,UITableViewDataSource>
// get moodle id from segue
@property(strong,nonatomic)NSString*moodeleID;
@property(strong,nonatomic)NSString*moodleName;
@property(strong,nonatomic)NSString*content;
@property (nonatomic, strong) NSMutableArray *fetchedObjects;
@property(strong)NSManagedObjectContext*passThis;
@property(strong,nonatomic)NSString*dataForSend;
@property(strong,nonatomic)NSArray*noteID;
@property(strong,nonatomic)NSArray*noteTitle;
@property(strong,nonatomic)NSArray*insertDates;
@property(strong,nonatomic)NSArray*noteContent;
@property (weak, nonatomic) IBOutlet UILabel *classTitleLable;
@property (weak, nonatomic) IBOutlet UITableView *allNotes;
@end
and this is my implementation file:
#import "ShowClassNote.h"
#import "Subjects.h"
#import "NewClassNote.h"
#import "Notes.h"
#import "AllClassNotesCell.h"
@interface ShowClassNote ()
@end
@implementation ShowClassNote
- (void)viewDidLoad {
    [super viewDidLoad];
    id delegate =[[UIApplication sharedApplication]delegate];
    NSError*error=nil;
    NSManagedObjectContext *context = [delegate managedObjectContext];
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Notes"
                                              inManagedObjectContext:context];
   NSPredicate * predicate =[NSPredicate predicateWithFormat:[NSString stringWithFormat:@"moodleCode=='%@'",self.moodeleID]];
    [fetchRequest setPredicate:predicate];
    [fetchRequest setEntity:entity];
    self.fetchedObjects = [[NSMutableArray alloc]initWithObjects:[context executeFetchRequest:fetchRequest error:&error], nil];
   // self.fetchedObjects =(NSMutableArray *) [context executeFetchRequest:fetchRequest error:&error];
   // NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
    self.noteTitle  =[[[NSArray alloc]initWithArray:_fetchedObjects]valueForKey:@"title"];
    self.insertDates  =[[[NSArray alloc]initWithArray:_fetchedObjects]valueForKey:@"insertDate"];
    self.noteContent  =[[[NSArray alloc]initWithArray:_fetchedObjects]valueForKey:@"content"];
    self.noteID=[[[NSArray alloc]initWithArray:_fetchedObjects]valueForKey:@"moodleCode"];
    self.classTitleLable.text=self.moodleName;
    self.title=self.moodleName;
    [self.allNotes reloadData];
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
-(UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section{
    return 0;
}
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {
    // This will create a "invisible" footer
    return 0.01f;
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    return [self.fetchedObjects count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString * cellIdnt =@"noteCell";
    AllClassNotesCell *cell =(AllClassNotesCell *) [tableView dequeueReusableCellWithIdentifier:cellIdnt forIndexPath:indexPath];
    // Configure the cell...
    // Get current date & time
    NSDate *currDate =  [self.insertDates objectAtIndex:indexPath.row];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
    [dateFormatter setDateFormat:@"dd/MM/YY HH:mm"];
    NSString* dateToString =[dateFormatter stringFromDate:currDate];
    cell.textLabel.text= [self.noteTitle objectAtIndex:indexPath.row]  ;
     cell.detailTextLabel.text=dateToString;
    return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 78;
}
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{
        id delegate =[[UIApplication sharedApplication]delegate];
        // Delete the role object that was swiped
        NSUInteger currentSelect = indexPath.row;
        NSManagedObjectContext *context = [delegate managedObjectContext];
        Notes * roleToDelete= [self.fetchedObjects objectAtIndex:currentSelect];
        [context deleteObject:roleToDelete];
        // Save the context.
        NSError *error;
        if (![context save:&error])
        {
            NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        }
    [_fetchedObjects removeObjectAtIndex:currentSelect];
    [self.allNotes reloadData];
}
-(void)viewWillAppear:(BOOL)animated{
    id delegate =[[UIApplication sharedApplication]delegate];
    NSError*error=nil;
    NSManagedObjectContext *context = [delegate managedObjectContext];
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Notes"
                                              inManagedObjectContext:context];
    NSPredicate * predicate =[NSPredicate predicateWithFormat:[NSString stringWithFormat:@"moodleCode=='%@'",self.moodeleID]];
    [fetchRequest setPredicate:predicate];
    [fetchRequest setEntity:entity];
     self.fetchedObjects = (NSMutableArray *)[context executeFetchRequest:fetchRequest error:&error];
    self.noteTitle  =[[[NSArray alloc]initWithArray:_fetchedObjects]valueForKey:@"title"];
    self.insertDates  =[[[NSArray alloc]initWithArray:_fetchedObjects]valueForKey:@"insertDate"];
    self.classTitleLable.text=self.moodleName;
    self.title=self.moodleName;
    [self.allNotes reloadData];
}
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([[segue identifier]isEqual:@"newNote"]) {
        NewClassNote * newNoteView =[segue destinationViewController];
        newNoteView.moodleID =self.moodeleID;
        newNoteView.newOrOld =YES;
    }else if ([[segue identifier]isEqual:@"showNote"])
    {
        NewClassNote * dvc =[segue destinationViewController];
        NSUInteger currentSelect = [self.allNotes indexPathForSelectedRow].row;
           NSLog(@"Send is %lu",(unsigned long)currentSelect);
        dvc.returnData =[self.fetchedObjects objectAtIndex:currentSelect];
        NewClassNote *destViewController = segue.destinationViewController;
        destViewController.comingData = [self.noteTitle objectAtIndex:[[self.allNotes indexPathForSelectedRow] row]];
        destViewController.insertDate=  [self.insertDates objectAtIndex:[[self.allNotes indexPathForSelectedRow] row]];
        [self.allNotes reloadData];
    }
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
@end
Can you explain to me why I get this error? The total rows after deletion is different than before deletion but I don't know why this errors?
 
     
    