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我正在爲iPad開發應用程序，但無法顯示已保存在覈心數據中的數據。我早些時候問過這個問題，很多人幫助過我，但我仍然遇到同樣的問題。這一次，在調試的時候，我得到了錯誤，我設置的數組接收取回的對象無法訪問。請再次幫助我，因爲這很緊急。我的代碼如下...核心數據：無法訪問通過獲取結果返回的託管對象控制器
#import "RootViewController.h"
#import "DetailViewController.h"
#import "AddViewController.h"
#import "EmployeeDetailsAppDelegate.h"
/*
This template does not ensure user interface consistency during editing operations in the table view. You must implement appropriate methods to provide the user experience you require.
*/
@interface RootViewController()
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath;
@end
@implementation RootViewController
@synthesize detailViewController, fetchedResultsController, managedObjectContext, array, dictionary;
//@synthesize array;
#pragma mark -
#pragma mark View lifecycle
- (void)viewDidLoad {
self.title = @"Employee Name";
self.navigationItem.rightBarButtonItem = self.editButtonItem;
[super viewDidLoad];
if (self.fetchedResultsController)
{
NSArray *tempArr = self.fetchedResultsController.fetchedObjects;
NSLog(@"temp array is %@",tempArr);
int count =[tempArr count];
int i;
for(i=0;i <count;i++)
{
NSManagedObject *category = [tempArr objectAtIndex:i];
dictionary = [[NSMutableDictionary alloc] initWithCapacity:0];
if([[category valueForKey:@"EmployeeName"] isKindOfClass:[NSString class]])
{
[dictionary setObject:[category valueForKey:@"EmployeeName"] forKey:@"EmployeeName"];
}
if([[category valueForKey:@"EmployeeID"] isKindOfClass:[NSString class]])
{
[dictionary setObject:[category valueForKey:@"EmployeeID"] forKey:@"EmployeeID"];
}
if([[category valueForKey:@"EmployeeDepartment"] isKindOfClass:[NSString class]])
{
[dictionary setObject:[category valueForKey:@"EmployeeDepartment"] forKey:@"EmployeeDepartment"];
}
[dictionary setObject:[NSNumber numberWithInt:0] forKey:@"EmployeeName"];
[self.array addObject:dictionary];
[dictionary release];
[tempArr release];
}
}
}
- (void)viewWillAppear:(BOOL)animated {
[self.tableView reloadData];
// [super viewWillAppear:animated];
}
/*
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
}
*/
/*
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
}
*/
/*
- (void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:animated];
}
*/
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Ensure that the view controller supports rotation and that the split view can therefore show in both portrait and landscape.
return YES;
}
#pragma mark -
#pragma mark Add a new object
- (void)insertNewObject:(id)sender {
AddViewController *add = [[AddViewController alloc]initWithNibName:@"AddViewController" bundle:nil];
self.modalPresentationStyle = UIModalPresentationFormSheet;
add.wantsFullScreenLayout = NO;
[self presentModalViewController:add animated:YES];
[add release];
}
#pragma mark -
#pragma mark Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
// return [sectionInfo numberOfObjects];
if([self.array count])
{
return [array count];
}
return 1;
}
- (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] autorelease];
}
// Configure the cell.
// [self configureCell:cell atIndexPath:indexPath];
if(dictionary = [array objectAtIndex:indexPath.row])
{
[dictionary objectForKey:@"EmployeeName"];
cell.textLabel.text = @"(EmployeeName = %@)";
}
else {
cell.textLabel.text = @"No Employee Name";
}
return cell;
}
-(void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath{
// AddViewController *detail = [fetchedResultsController objectAtIndexPath:indexPath];
// cell.textLabel.text = detail.empName.text;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete) {
// Delete the managed object.
NSManagedObject *objectToDelete = [self.fetchedResultsController objectAtIndexPath:indexPath];
if (self.detailViewController.detailItem == objectToDelete) {
self.detailViewController.detailItem = nil;
}
NSManagedObjectContext *context = [fetchedResultsController managedObjectContext];
[context deleteObject:[fetchedResultsController objectAtIndexPath:indexPath]];
NSError *error;
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. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
}
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {
// The table view should not be re-orderable.
return NO;
}
#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Set the detail item in the detail view controller.
detailViewController = [[DetailViewController alloc]initWithStyle:UITableViewStylePlain];
// AddViewController *selectedName = (AddViewController *)[[self fetchedResultsController]objectAtIndexPath:indexPath];
// detailViewController.detail = selectedName;
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
#pragma mark -
#pragma mark Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController {
if (fetchedResultsController != nil) {
return fetchedResultsController;
}
/*
Set up the fetched results controller.
*/
// Create the fetch request for the entity.
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Details" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"EmployeeName" ascending:NO];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
AddViewController *name = [[AddViewController alloc]init];
if (name.empName.text) {
NSPredicate *inPredicate = [NSPredicate predicateWithFormat: @"EmployeeName = %@", name.empName.text];
[fetchRequest setPredicate:inPredicate];
}
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
[aFetchedResultsController release];
[fetchRequest release];
[sortDescriptors release];
return fetchedResultsController;
}
#pragma mark -
#pragma mark Fetched results controller delegate
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *tableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
[self.tableView endUpdates];
}
#pragma mark -
#pragma mark Memory management
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Relinquish ownership any cached data, images, etc. that aren't in use.
}
- (void)viewDidUnload {
self.fetchedResultsController = nil;
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
// self.array = nil;
}
- (void)dealloc {
// [array release];
[detailViewController release];
[fetchedResultsController release];
[managedObjectContext release];
[super dealloc];
}
@end
問候， Dipanjan
請發佈較少的代碼。 – 2011-02-25 12:47:05