iOS_SN_CoreData(二)

上一篇是講怎麼進行CoreData的基本操做，這一篇是講NSFetchedResultsController獲得CoreData數據怎麼與tableView完美結合，和動畫操做的實現。

NSFetchedResultsController的結果與tableView的結合

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return [[self.queryData sections] count];
}

- (NSInteger)tableView:(UITableView *)table numberOfRowsInSection:(NSInteger)section {
    if ([[self.queryData sections] count] > 0) {
        id <NSFetchedResultsSectionInfo> sectionInfo = [[self.queryData sections] objectAtIndex:section];
        return [sectionInfo numberOfObjects];
    } else
        return 0;
}

　　

NSFetchedResultsControllerDelegate代理方法的實現

CoreData中數據將要改變調用的方法

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller {
    
    // The fetch controller is about to start sending change notifications, so prepare the table view for updates.
    [self.tableView beginUpdates];
}

CoreData中行數據改變調用的方法能夠在數據改變時實現某些動畫

- (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:@[newIndexPath] withRowAnimation:UITableViewRowAnimationRight];
            break;
            
        case NSFetchedResultsChangeDelete:
            [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationBottom];
            break;
            
        case NSFetchedResultsChangeUpdate:
            [tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationLeft];
            break;
            
        case NSFetchedResultsChangeMove:
            [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
            [tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
            break;
    }
}

CoreData中組的數據改變時調用的方法也能夠實現某些動畫

- (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:UITableViewRowAnimationAutomatic];
            break;
        case NSFetchedResultsChangeMove:
            break;
        case NSFetchedResultsChangeUpdate:
            break;
        case NSFetchedResultsChangeDelete:
            [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationAutomatic];
            break;
    }
}

CoreData中的數據已經改變時調用的方法

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller {
    self.dataList = self.queryData.fetchedObjects.mutableCopy;
    NSLog(@"%@",self.dataList);
    [self.tableView endUpdates];
}

　　

本文GitHub地址https://github.com/zhangkiwi/iOS_SN_CoreData