我允许用户从UIDatePicker
视图中选择日期,然后UITableView
的标题将显示来自选择器视图的日期。我的问题是,UITableView
是否可以根据UITableView
标题的日期自动重新排列从旧到新的项目并重新加载表格?
这是我的代码,
@interface PictureListMainTable : UITableViewController{
}
@property (strong, nonatomic) NSManagedObjectContext *managedObjectContext;
@property (strong, nonatomic) NSMutableArray *pictureListData;
- (void)readDataForTable;
@end
@synthesize managedObjectContext, pictureListData;
@synthesize scroll;
- (void)viewWillAppear:(BOOL)animated
{
// Repopulate the array with new table data
[self readDataForTable];
NSCalendar *cal = [NSCalendar currentCalendar];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:@"dd.MMMM - EEEE"];
NSDate *today = [NSDate date];
[pictureListData enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
Pictures *picture = (Pictures *)obj;
NSDate *date = [dateFormatter dateFromString:picture.title];
NSDateComponents *components = [cal components:NSDayCalendarUnit
fromDate:date
toDate:today
options:0];
if ([components day]==0) {
*stop = TRUE;
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:idx inSection:0];
[self.tableView scrollToRowAtIndexPath:indexPath
atScrollPosition:UITableViewScrollPositionTop
animated:YES];
}
}];
}
// When the view reappears, read new data for table
// Grab data for table - this will be used whenever the list appears or reappears after an add/edit
- (void)readDataForTable
{
// Grab the data
pictureListData = [CoreDataHelper getObjectsForEntity:@"Pictures" withSortKey:@"title" andSortAscending:YES andContext:managedObjectContext];
// Force table refresh
[self.tableView reloadData];
}
#pragma mark - Actions
// Button to log out of app (dismiss the modal view!)
#pragma mark - Segue methods
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get a reference to our detail view
PictureListDetail *pld = (PictureListDetail *)[segue destinationViewController];
// Pass the managed object context to the destination view controller
pld.managedObjectContext = managedObjectContext;
// If we are editing a picture we need to pass some stuff, so check the segue title first
if ([[segue identifier] isEqualToString:@"EditPicture"])
{
// Get the row we selected to view
NSInteger selectedIndex = [[self.tableView indexPathForSelectedRow] row];
// Pass the picture object from the table that we want to view
pld.currentPicture = [pictureListData objectAtIndex:selectedIndex];
}
}
#pragma mark - Table view data source
// Return the number of sections in the table
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
// Return the number of rows in the section (the amount of items in our array)
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [pictureListData count];
}
// Create / reuse a table cell and configure it for display
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
// Get the core data object we need to use to populate this table cell
Pictures *currentCell = [pictureListData objectAtIndex:indexPath.row];
// Fill in the cell contents
cell.textLabel.text = [currentCell title];
cell.detailTextLabel.text = [currentCell desc];
// If a picture exists then use it
if ([currentCell smallPicture])
{
cell.imageView.contentMode = UIViewContentModeScaleAspectFit;
cell.imageView.image = [UIImage imageWithData:[currentCell smallPicture]];
}
return cell;
}
// Swipe to delete has been used. Remove the table item
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete)
{
// Get a reference to the table item in our data array
Pictures *itemToDelete = [self.pictureListData objectAtIndex:indexPath.row];
// Delete the item in Core Data
[self.managedObjectContext deleteObject:itemToDelete];
// Remove the item from our array
[pictureListData removeObjectAtIndex:indexPath.row];
// Commit the deletion in core data
NSError *error;
if (![self.managedObjectContext save:&error])
NSLog(@"Failed to delete picture item with error: %@", [error domain]);
// Delete the row from the data source
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
}
@end
感谢。