ios – NSFetchedResultsController v.s. UILocalizedIndexedCollat​​ion

似乎从文档中你应该可以覆盖FRC的

- (Nsstring *)sectionIndexTitleForSectionName:(Nsstring *)sectionName
- (NSArray *)sectionIndexTitles

然后使用UILocalizedindexedCollat​​ion来具有本地化的索引和部分.但可悲的是,这并不奏效

有没有人能够使用带有UILocalizedindexedCollat​​ion的FRC,或者我们被迫使用示例UITableView UILocalizedindexedCollat​​ion示例中提到的手动排序方法(包含我在这里工作的示例代码).

使用以下属性

@property (nonatomic,assign) UILocalizedindexedCollation *collation;
@property (nonatomic,assign) NSMutableArray *collatedSections;

和代码：

- (UILocalizedindexedCollation *)collation
{
    if(collation == nil)
    {
        collation = [UILocalizedindexedCollation currentCollation];
    }

    return collation;
}

- (NSArray *)collatedSections
{
    if(_collatedSections == nil)
    {
        int sectionTitlesCount = [[self.collation sectionTitles] count];

        NSMutableArray *newSectionsArray = [[NSMutableArray alloc] initWithCapacity:sectionTitlesCount];
        collatedSections = newSectionsArray;
        NSMutableArray *sectionsCArray[sectionTitlesCount];

        // Set up the sections array: elements are mutable arrays that will contain the time zones for that section.
        for(int index = 0; index < sectionTitlesCount; index++) 
        {
            NSMutableArray *array = [[NSMutableArray alloc] init];
            [newSectionsArray addobject:array];
            sectionsCArray[index] = array;
            [array release];
        }


        for(NSManagedobject *call in self.fetchedResultsController.fetchedobjects)
        {
            int section = [collation sectionForObject:call collationStringSelector:NSSelectorFromString(name)];
            [sectionsCArray[section] addobject:call];
        }

        NSArray *sortDescriptors = self.fetchedResultsController.fetchRequest.sortDescriptors;
        for(int index = 0; index < sectionTitlesCount; index++) 
        {
            [newSectionsArray replaceObjectAtIndex:index withObject:[sectionsCArray[index] sortedArrayUsingDescriptors:sortDescriptors]];
        }
    }
    return [[collatedSections retain] autorelease];
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{
    // The number of sections is the same as the number of titles in the collation.
    return [[self.collation sectionTitles] count];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
    // The number of time zones in the section is the count of the array associated with the section in the sections array.
    return [[self.collatedSections objectAtIndex:section] count];
}


- (Nsstring *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section 
{
    if([[self.collatedSections objectAtIndex:section] count])
        return [[self.collation sectionTitles] objectAtIndex:section];
    return nil;
}


- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
    return [self.collation sectionIndexTitles];
}


- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(Nsstring *)title atIndex:(NSInteger)index {
    return [self.collation sectionForSectionIndexTitleAtIndex:index];
}

我希望仍然可以使用FRCDelegate协议通知更新.似乎没有一个很好的方式使这两个对象很好地协同工作.