NSFetchedResultsController具有节名称 [英] NSFetchedResultsController with section names
问题描述
情况：
我有一笔费用跟踪iOS应用程序，我将费用从费用明细视图控制器存储到表视图（带有提取的结果控制器）费用清单以及类别，金额和日期。我在我的实体金钱中有一个日期属性，它是费用或收入的父实体。
I have an expense tracking iOS Application and I am storing expenses from a expense detail view controller into a table view (with fetched results controller) that shows the list of expenses along with the category and amount and date. I do have a date attribute in my entity "Money" which is a parent entity for either an expense or an income.
我的问题：
我想要的是基本分类给定周，一个月或一年的费用/收入，并显示为节标题，例如：（2012年10月1日 - 10月7日）它显示根据该特定周的费用/收入金额和相关的东西。在该视图中提供了两个按钮，如果我按右边的按钮，它将增加一周一个星期（2012年10月1日 - 10月7日现在显示2012年10月8日 - 2012年10月15日），类似地，左按钮将递减一周一周。我在视图中也有两个段控件。我想做的是按下段控制，说每周，如果我按另一个段，说类别 - 我如何根据类别过滤每周的费用/收入？
What I want is to basically categorize my expenses/incomes for a given week, a month, or year and display it as the section header title for example : (Oct 1- Oct 7, 2012) and it shows expenses/incomes amount and related stuff according to that particular week. Two buttons are provided in that view, if I would press the right button, it will increment the week by a week (Oct 1- Oct 7, 2012 now shows Oct8 - Oct 15, 2012) and similarly the left button would decrement the week by a week. I have two segment controls in the view as well. What I want to do is press the segment control which says "weekly" and if I press another segment which says "category" - how would I filter out my expenses/incomes per week based on category ?
我想在表格视图中显示两个部分（一个显示费用日期，另一个显示收入日期格式（Oct1,2012 - Oct7， 2012年））。我将如何实现这一点？我写了一些伪代码，如果有人可以告诉我如何完成上述，这将是巨大的。
I want to display two sections in my table view (one which shows the date for expenses and another to show the date for incomes in format (Oct1,2012 - Oct7, 2012)). How would I achieve this? I have written some pseudo code and if anybody can tell me how would I accomplish the above, that would be great.
编辑 - FETCH控制器
EDIT - FETCH CONTROLLER
- (void)userDidSelectStartDate:(NSDate *)startDate andEndDate:(NSDate *)endDate
{
AppDelegate * applicationDelegate = (AppDelegate *) [[UIApplication sharedApplication] delegate];
NSManagedObjectContext * context = [applicationDelegate managedObjectContext];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Money" inManagedObjectContext:context];
[fetchRequest setEntity:entity];
[NSFetchedResultsController deleteCacheWithName:nil];
//Here you create the predicate that filters the results to only show the ones with the selected date
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(date >= %@) AND (date <= %@)", startDate, endDate];
[fetchRequest setPredicate:predicate];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor * sortDescriptor1 = [[NSSortDescriptor alloc] initWithKey:@"type" ascending:YES];
NSSortDescriptor *sortDescriptor2 = [[NSSortDescriptor alloc] initWithKey:@"date" ascending:YES];
NSSortDescriptor *sortDescriptor3 = [[NSSortDescriptor alloc] initWithKey:@"cat" ascending:YES];
NSArray * descriptors = [NSArray arrayWithObjects:sortDescriptor1, sortDescriptor2, sortDescriptor3, nil];
[fetchRequest setSortDescriptors:descriptors];
[fetchRequest setIncludesSubentities:YES];
[fetchRequest setResultType:NSManagedObjectResultType];
if(_fetchedResultsController)
{
[_fetchedResultsController release]; _fetchedResultsController = nil;
}
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
_fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:context sectionNameKeyPath:@"type" cacheName:nil];
_fetchedResultsController.delegate = self;
NSError *anyError = nil;
if(![_fetchedResultsController performFetch:&anyError])
{
NSLog(@"error fetching:%@", anyError);
}
[sortDescriptor1 release];
[sortDescriptor2 release];
[sortDescriptor3 release];
[fetchRequest release];
//Finally you tell the tableView to reload it's data, it will then ask your NEW FRC for the new data
[self.dashBoardTblView reloadData];
}
EDIT - 获取控制器委托方法
EDIT - Fetch Controller Delegate Methods
- (void)controllerWillChangeContent:(NSFetchedResultsController*)controller
{
[self.dashBoardTblView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type {
switch(type) {
case NSFetchedResultsChangeInsert:
[self.dashBoardTblView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.dashBoardTblView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex]
withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath{
switch(type) {
case NSFetchedResultsChangeInsert:
[self.dashBoardTblView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.dashBoardTblView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeMove:
[self.dashBoardTblView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]
withRowAnimation:UITableViewRowAnimationFade];
[self.dashBoardTblView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]
withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
{
[self.dashBoardTblView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.dashBoardTblView endUpdates];
}
推荐答案
/收入对象分成不同的部分，您需要向 Money 实体添加类型属性，例如属性 0 用于支出， 1 用于收入
To group the "Expense"/"Income" objects into different sections, you need to add a type attribute to the Money entity, for example a Integer attribute that is 0 for expenses and 1 for incomes.
要按类型（费用/收入）对表视图节进行排序，请先使用键入 sort descriptor：
To sort the table view sections by type (expense/income), use type as first sort descriptor:
NSSortDescriptor *s1 = [[NSSortDescriptor alloc] initWithKey:@"type" ascending:YES];
要按日期对每个部分中的条目排序，请使用 date 作为第二个排序描述符：
To sort the entries within each section by date, use date as second sort descriptor:
NSSortDescriptor *s2 = [[NSSortDescriptor alloc] initWithKey:@"date" ascending:YES];
NSArray *descriptors = [NSArray arrayWithObjects:s1, s2, nil];
[fetchRequest setSortDescriptors:descriptors];
最后，要根据类别将表视图分成几个部分，请使用 / code> as sectionNameKeyPath ：
Finally, to group the table view into sections by category, use type as sectionNameKeyPath:
NSFetchedResultsController *aFetchedResultsController =
[[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:context
sectionNameKeyPath:type
cacheName:nil];
这应该给出2节，第一节包含所有费用，第二节包含所有收入。
This should give 2 sections, with all expenses in the first section and all incomes in the second section.
现在对于节头你必须实现 tableView：viewForHeaderInSection：（我希望我得到这个权利） ：
Now for the section headers you have to implement tableView:viewForHeaderInSection: (I hope that I get this right):
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
Money *money = [[sectionInfo objects] objectAtIndex:0]; // The first object in this section
NSNumber *type = money.type;
if (type.intValue == 0) {
// Create and return header view for "expense" section.
} else {
// Create and return header view for "incomes" section.
}
}
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