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我很難在tableView中實現2 nsfetchedresultsController。我在表（2段）的每個部分想要一個fetchedresultsController，是這樣的：
UItableView上的多個NsfetchedResultsController
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- 產品
- 產品2
買
- 產品3
我知道，在這個例子中，我不會需要2 nsfetchedResultsController但後來我需要..
當我刪除從一個nsfetchedResultsController把它傳遞給其他的產品，我得到這個錯誤：
Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (0) must be equal to the number of rows contained in that section before the update (0), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted). with userInfo (null)"
我認爲，這是因爲當第一fetchedRController檢測到變化它的第二個被稱爲是正確的之前更新的tableView？我應該使用NSMutableArrays並手動更新tableView嗎？
代碼：
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSInteger numberOfRows = 0;
switch (section)
{
case WISHLIST_SECTION:
{
numberOfRows =[[fetchedResultsControllerwish fetchedObjects]count];
};
break;
case PURCHASED_SECTION:
{
numberOfRows =[[fetchedResultsControllerPurchased fetchedObjects]count];
};
break;
default:
break;
}
return numberOfRows;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
// The fetch controller is about to start sending change notifications, so prepare the table view for updates.
[self.tableView beginUpdates];
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
// The fetch controller has sent all current change notifications, so tell the table view to process all updates.
[self.tableView endUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath {
UITableView *tableViewT = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableViewT insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableViewT deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:(GiftEventTableViewCell *)[tableViewT cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableViewT deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
[tableViewT insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
-(void)configureCell:(GiftEventTableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
switch (indexPath.section) {
case WISHLIST_SECTION:
{
GiftEvent *giftEv=(GiftEvent *)[fetchedResultsControllerwish objectAtIndexPath:indexPath];
cell.gift=giftEv;
};
break;
case PURCHASED_SECTION:
{
GiftEvent *giftEv=(GiftEvent *)[fetchedResultsControllerPurchased objectAtIndexPath:indexPath];
//if i don't use indexpath.row in the second section i get an out of bounds error
//GiftEvent *giftEv=(GiftEvent *)[[fetchedResultsControllerPurchased fetchedObjects]objectAtIndex: indexPath.row];
cell.gift=giftEv;
};
break;
default:
break;
}
}
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
if (editingStyle == UITableViewCellEditingStyleDelete)
{
switch (indexPath.section) {
case WISHLIST_SECTION:
{
// Delete the managed object for the given index path
[self.managedObjectContext deleteObject:[fetchedResultsControllerwish objectAtIndexPath:indexPath]];
// Save the context.
NSError *error;
if (![self.managedObjectContext 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();
}
[self.tableView reloadData];
};
break;
case PURCHASED_SECTION:
{
// Delete the managed object for the given index path
[self.managedObjectContext deleteObject:[fetchedResultsControllerPurchased objectAtIndexPath:indexPath]];
// Save the context.
NSError *error;
if (![self.managedObjectContext 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();
}
};
break;
default:
break;
}
}
}
這是我使用的確切的方法，但我得到那個錯誤.. – ricastro 2010-09-03 15:36:26