设想:
我有一个费用跟踪 iOS 应用程序,我将费用从费用详细视图控制器存储到表视图(带有获取的结果控制器)中,该表视图显示费用列表以及类别、金额和日期。我的实体“Money”中确实有一个日期属性,它是支出或收入的父实体。
我的问题:
我想要的是基本上对给定一周、一个月或一年的费用/收入进行分类,并将其显示为部分标题标题,例如:(2012 年 10 月 1 日至 10 月 7 日),它显示费用/收入金额和相关根据那一周的东西。该视图中提供了两个按钮,如果我按下右侧按钮,它将一周增加一周(2012 年 10 月 1 日至 10 月 7 日现在显示 2012 年 10 月 8 日至 10 月 15 日),同样,左侧按钮将减少一周一个星期。我在视图中也有两个段控件。我想要做的是按下显示“每周”的段控制,如果我按下另一个显示“类别”的段 - 我将如何根据类别过滤掉我每周的费用/收入?
我想在我的表格视图中显示两个部分(一个显示费用日期,另一个显示格式的收入日期(2012 年 10 月 1 日 - 2012 年 10 月 7 日))。我将如何实现这一目标?我写了一些伪代码,如果有人能告诉我如何完成上述操作,那就太好了。
编辑 - 获取控制器
- (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];
}
编辑 - 获取控制器委托方法
- (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];
}