所以我似乎无法在我的tableview中显示任何数据,但后来我注意到上下文没有保存,我不断收到此错误:
[NSManagedObjectContext(MagicalSaves) MR_saveWithOptions:completion:](0x166a70b0) NO CHANGES IN ** DEFAULT ** CONTEXT - NOT SAVING
2014-04-12 19:49:04.722 0DataCollector[3218:60b] Managedcontext working (
TestSuburb
)
- (IBAction)backToSuburbsTableViewController:(UIStoryboardSegue *)segue {
if ([segue.sourceViewController isKindOfClass:[NewSuburbTableViewController class]]) {
NSLog(@"Coming back from NewSuburbTableViewController");
NewSuburbTableViewController *srcVC = segue.sourceViewController;
suburbString = srcVC.suburbTextField.text;
[suburbsArray addObject:suburbString];
//Save Managed Object Context
[[NSManagedObjectContext defaultContext] saveToPersistentStoreWithCompletion:^(BOOL success, NSError *error) {
if (success) {
NSLog(@"You successfully saved your context.");
} else if (error) {
NSLog(@"Error saving context: %@", error.description);
}
}]; NSLog(@"Managedcontext working %@", suburbsArray);
}
我们非常感谢您提供的任何帮助,我也尝试过保存" contextWithinCurrentThread"没有帮助。
TableViewController的其余代码:
- (void)viewDidLoad
{
[super viewDidLoad];
suburbsArray = [[NSMutableArray alloc] init];
[self fetchSuburbs];
// 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;
}
- (void)fetchSuburbs {
//Fetch suburbs
self.suburbsArray = [NSMutableArray arrayWithArray:[Suburb findAllSortedBy:@"name" ascending:YES]];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self fetchSuburbs];
[self.tableView reloadData];
}
#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 [suburbsArray count];
}
- (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];
}
NSMutableArray *reversedSuburbsArray = [[[suburbsArray reverseObjectEnumerator] allObjects] mutableCopy];
//Fetch suburb
Suburb *suburb = [self.suburbsArray objectAtIndex:indexPath.row];
// Configure the cell...
cell.textLabel.text = suburb.name;
return cell;
}
答案 0 :(得分:3)
也许你不是在创建和插入新的NSmanagedObject"郊区"进入上下文,所以没有变化。在这种情况下,您的问题不在于保存,没有什么可以保存。
添加到可变数组不会创建新的郊区。您只创建了一个与任何NSmanagedObject无关的字符串对象。
然后我建议:- (IBAction)backToSuburbsTableViewController:(UIStoryboardSegue *)segue {
if ([segue.sourceViewController isKindOfClass:[NewSuburbTableViewController class]]) {
NSLog(@"Coming back from NewSuburbTableViewController");
NewSuburbTableViewController *srcVC = segue.sourceViewController;
suburbString = srcVC.suburbTextField.text;
[suburbsArray addObject:suburbString];
// Create the new suburb
Suburb *theNewBurb = [Suburb createEntity];
theNewBurb.burbName = suburbString; // I don't know what properties you have on Suburb so you would need to correct this
// You also need to set any other required properties of Suburb prior to save or it will fail
//Save Managed Object Context
[[NSManagedObjectContext defaultContext] saveToPersistentStoreWithCompletion:^(BOOL success, NSError *error) {
if (success) {
NSLog(@"You successfully saved your context.");
} else if (error) {
NSLog(@"Error saving context: %@", error.description);
}
}]; NSLog(@"Managedcontext working %@", suburbsArray);
}