セクションの最後の行を削除すると NSInternalInconsistencyException でアプリが終了するという UITableView に問題があります。
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (1) must be equal to the number of rows contained in that section before the update (1), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'
私の UITableView には、MPMediaItemCollection (self.detailCollection) からの MPMediaItems が取り込まれます。最後のものが削除されたら、空白のセルに「結果が見つかりません」というラベルを表示したいと思います。
ここに私の cellForRowAtIndexPath があります:
- (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] autorelease];
}
// Configure the cell...
if ([[self.detailCollection items] count] == 0) {
[tableView numberOfRowsInSection:1];
cell.textLabel.text = @"No results found";
//return cell;
} else {
MPMediaItem *song = (MPMediaItem *)[[self.detailCollection items] objectAtIndex:[indexPath row]];
if (song) {
cell.textLabel.text = [song valueForProperty:MPMediaItemPropertyTitle];
MPMediaItemArtwork *art = [song valueForProperty:MPMediaItemPropertyArtwork];
cell.imageView.image = [art imageWithSize:CGSizeMake(64, 64)];
}
}
return cell;
}
行を削除するための私のコードは次のとおりです。
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
PlaylistData *pData = [PlaylistData getInstance];
NSMutableArray *tempArray = [[self.eventDictionary valueForKey:[NSString stringWithFormat:@"%@", pData.selectedEvent]] mutableCopy];
NSMutableArray *newArray = [[NSMutableArray alloc] init];
if (editingStyle == UITableViewCellEditingStyleDelete) {
[tableView beginUpdates];
// Delete the row from the data source
[tempArray removeObjectAtIndex:indexPath.row];
[self.eventDictionary setValue:tempArray forKey:[NSString stringWithFormat:@"%@", pData.selectedEvent]];
[[NSUserDefaults standardUserDefaults] setValue:self.eventDictionary forKey:@"Playlist Items"];
[[NSUserDefaults standardUserDefaults] synchronize];
if ([tempArray count] == 0) {
[tableView numberOfRowsInSection:1];
}
for (int i=0; i<[tempArray count]; i++) {
NSString *pID = [NSString stringWithFormat:@"%@", [tempArray objectAtIndex:i]];
unsigned long long ullvalue = strtoull([pID UTF8String], NULL, 0);
NSNumber *UniqueID = [NSNumber numberWithUnsignedLongLong:ullvalue];
MPMediaQuery *cellQuery = [[MPMediaQuery alloc] init];
[cellQuery addFilterPredicate:[MPMediaPropertyPredicate predicateWithValue:UniqueID forProperty:MPMediaItemPropertyPersistentID]];
for (MPMediaItem *item in [cellQuery items]) {
[newArray addObject:item];
}
[cellQuery release];
}
if (![newArray count] == 0) {
self.detailCollection = [[MPMediaItemCollection alloc] initWithItems:newArray];
[tableView numberOfRowsInSection:[self.detailCollection count]];
} else {
[tableView numberOfRowsInSection:1];
[tableView reloadData];
}
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView endUpdates];
}
else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
そして、ここに私のnumberOfRowsInSectionがあります:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
if ([[self.detailCollection items] count] == 0 || [self.detailCollection items] == nil || [self.detailCollection items] == NULL) {
return 1;
}
return [[self.detailCollection items] count];
}
私の質問は: self.detailCollection が == 0 のときに「結果が見つかりません」セルを作成しないのはなぜですか?