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私は 2 つの tableViews を持っています。主なものは親オブジェクトを追加し、tableView で親オブジェクトをクリックすると、子 tableView に移動します。最初の部分は成功しましたが、「RIGHT」のフェッチに関しては子オブジェクト私は混乱します、私はそれをすべての子オブジェクトをフェッチすることです.enumerationを使用して正しいものを選択し、NSSetに入れますが、それは機能しません.子オブジェクトテーブルview.mは次のとおりです。

 #import "MinorGoalsTableViewController.h"

 @interface MinorGoalsTableViewController ()

 @end

 @implementation MinorGoalsTableViewController
 @synthesize selectedGoal = _selectedGoal;
 @synthesize fetchedResultsController = _fetchedResultsController;
 @synthesize minorGoalsSet;

 // init with goal (for GTVC)
 - (id) initWithGoal:(Goal *)goal {
if (self = [super init]) {

    _selectedGoal = goal;

}

return self;
 }

 - (id)initWithStyle:(UITableViewStyle)style
 {
self = [super initWithStyle:style];
if (self) {
    // Custom initialization
}
return self;
 }

 - (void)viewDidLoad
 {
[super viewDidLoad];
NSError *error = nil;

// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;

// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;




NSLog(@"Minor Goals in %@ are: %lu", self.selectedGoal.title , (unsigned long)[self.selectedGoal.minorGoal count]);


 //    self.minorGoalsSet = nil;

// initializing minorGoalsSet
self.minorGoalsSet = [[NSMutableSet alloc] init];

// performing fetch
if (![self.fetchedResultsController performFetch:&error]) {
    NSLog(@"Error fetching all minor goals: %@", error);
    abort();
}


// creating NSSet that will carry all selectedGoal minor goals
NSSet *minorGoals = self.selectedGoal.minorGoal;


// creating a loop to add minor goals in minorGoalsSet
// add existing minor goals in selected goal to minorGoalsSet
for (MinorGoal *minor in minorGoals) {
    [minorGoalsSet addObject:minor];
}

NSLog(@"minor goals in set: %lu", (unsigned long) [minorGoalsSet count]);
NSLog(@"minor goals in set2: %lu", (unsigned long) [minorGoals count]);

// setting nav title to selected goal title
self.navigationItem.title = _selectedGoal.title;

// adding "add" button to nav
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addNewMinorGoal)];


 }

 - (void) viewWillDisappear:(BOOL)animated {
self.selectedGoal = nil;
 }


   - (void)didReceiveMemoryWarning
  {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
  }

プラグマ マーク - テーブル ビュー データ ソース

   - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
  {
return [self.selectedGoal.minorGoal count];
//    id <NSFetchedResultsSectionInfo> secInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
//    return [secInfo numberOfObjects];
  }

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
 {
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}

cell.accessoryType = UITableViewCellAccessoryNone;

// Configure the cell...
MinorGoal *minor = [self.fetchedResultsController objectAtIndexPath:indexPath];

// well see about that later
if ([minorGoalsSet containsObject:minor]) {
    cell.textLabel.text = minor.title;
}

// setting cell's title to minor goal's title
 //    cell.textLabel.text = minor.title;

return cell;
 }

pragma mark - フェッチされた結果コントローラ メソッド

 - (NSFetchedResultsController*) fetchedResultsController {
if (_fetchedResultsController != nil) {
    return _fetchedResultsController;
}

// creating fetch request
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
     NSEntityDescription *entity = [NSEntityDescription entityForName:@"MinorGoal"
                                             inManagedObjectContext:self.selectedGoal.managedObjectContext];
[fetchRequest setEntity:entity];

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"title"
                                                               ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];


// setting _fetchedResultsController
   _fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.selectedGoal.managedObjectContext sectionNameKeyPath:nil cacheName:nil];

// performing fetch
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error]) {
    NSLog(@"Error fetching minors: %@", error);
}

// returning
return _fetchedResultsController;

    }

プラグマ マーク - テーブル ビュー デリゲート

   - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 {

 }

 - (void) addNewMinorGoal {

// code to show UIAlertView that will add new minor goal
// creating UIAlertView
    UIAlertView *addMinorGoalAlert = [[UIAlertView alloc] initWithTitle:@"Add Minor Goal" message:@"Minor Goal Title" delegate:self cancelButtonTitle:@"Cancel"      otherButtonTitles:@"Save", nil];

// Adding plain textfield for minor goal title
addMinorGoalAlert.alertViewStyle = UIAlertViewStylePlainTextInput;

// showing UIAlertView
[addMinorGoalAlert show];
}

pragma mark - 新しいマイナー委任を追加するための UIAlertView

  - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {



      if (buttonIndex == 0) {
          NSLog(@"Adding Minor Goal Canceled!");
     }

      else

     {



    // creating string will carry textField value
    NSString *minorTitle = [[alertView textFieldAtIndex:0]text];





    // creating new minor goal
    MinorGoal *newMinorGoal = [NSEntityDescription
                               insertNewObjectForEntityForName:@"MinorGoal"
                                  inManagedObjectContext:self.selectedGoal.managedObjectContext];




    // setting title of new minor goal
    newMinorGoal.title = minorTitle;




    [self.selectedGoal addMinorGoalObject:newMinorGoal];



    // saving
    NSError *error = nil;
    if (![self.selectedGoal.managedObjectContext save:&error]) {
        NSLog(@"Error saving new minor goal: %@", error);
    }
    NSLog(@"we save %@ to %@ and theres %lu in it", newMinorGoal.title,      self.selectedGoal.title, (unsigned long) [self.selectedGoal.minorGoal count]);


    // fetching
    [self.fetchedResultsController performFetch:&error];


    // reloading tableView data
    [self.tableView reloadData];

   }
  }












 @end

正しい子オブジェクトを取得する正しい方法を教えてください。それらを NSSet に入れる必要がありますか?

4

3 に答える 3

0

親オブジェクトを子View Controllerのどこかに保存します。通常は次のようにする必要があります

.h ファイル:

@property (nonactomic, strong) ParentObject *parentObject;

.m ファイル

- (id)initWithObject:(ParentObject *)parent {
…
_parentObject = parent;
…
}

次にフェッチします:(持っている必要があります@property (nonatomic, strong) NSFecthedResultsController *fetchedResultController

- (NSFetchedResultsController*)fetchedResultController {
    if (_fetchedResultController) {
        return _fetchedResultController;
    }

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:NSStringFromClass([ChildObject class])];
    [request setEntity:entity];
    NSSortDescriptor *sortDescription = [NSSortDescriptor sortDescriptorWithKey:@"sortOrder" ascending:YES];
    [request setSortDescriptors:@[sortDescription]];
    request.predicate = [NSPredicate predicateWithFormat:@"(parent == %@)", self.parentObject];
    NSFetchedResultsController *controller = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:[NSManagedObjectContext mainThreadContext] sectionNameKeyPath:nil cacheName:nil];
    controller.delegate = self;
    _fetchedResultController = controller;
    return _fetchedResultController;
}

次にメソッドを実装します

- (void)performFetch {
    NSError *error = nil;
    [self.fetchedResultController performFetch:&error];
    if (![self.fetchedResultController performFetch:&error]) {
        [self showAlertWithError:error];
    }
    else {
        [self.tableView reloadData];
    }
}

つまり、基本的に、述語でソートおよびフィルタリングする必要があるすべての子オブジェクトを受け取ります

于 2013-09-18T02:15:30.493 に答える