我有一个包含几个部分的tableview。我希望能够将行从一个部分移动到另一个部分,并在没有行时删除部分。我试图通过moveRowAtIndexPath执行此操作,但我的代码不起作用并抛出NSRangeException异常。
以下是代码示例:
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
NSUInteger fromSection = [fromIndexPath section];
NSUInteger fromRow = [fromIndexPath row];
NSString *fromKey = [self.keys objectAtIndex:fromSection];
NSMutableArray *fromEventSection = [self.eventsDict objectForKey:fromKey];
NSUInteger toSection = [toIndexPath section];
NSUInteger toRow = [toIndexPath row];
NSString *toKey = [self.keys objectAtIndex:toSection];
NSMutableArray *toEventSection = [self.eventsDict objectForKey:toKey];
id object = [[fromEventSection objectAtIndex:fromRow] retain];
[fromEventSection removeObjectAtIndex:fromRow];
[toEventSection insertObject:object atIndex:toRow];
[object release];
// The above code works just fine!
// Try to delete an empty section. Here is where trouble begins:
if ((fromSection != toSection) && [fromEventSection count] == 0) {
[self.keys removeObjectAtIndex:fromSection];
[self.eventsDict removeObjectForKey:fromKey];
[tableView deleteSections:[NSIndexSet indexSetWithIndex:fromSection] withRowAnimation:UITableViewRowAnimationFade];
}
答案 0 :(得分:3)
我很幸运在moveRowAtIndexPath方法结束后的一个块中执行了deleteSections方法,方法是将删除包装在dispatch_async中。
dispatch_async(dispatch_get_main_queue(), ^{
if ((fromSection != toSection) && [fromEventSection count] == 0) {
[self.keys removeObjectAtIndex:fromSection];
[self.eventsDict removeObjectForKey:fromKey];
[tableView deleteSections:[NSIndexSet indexSetWithIndex:fromSection] withRowAnimation:UITableViewRowAnimationFade];
}
});
答案 1 :(得分:0)
这也让我有些悲伤。我已成功使用延迟执行部分删除。
以下是我如何使用它 - 假设您使用商店来包含所有对象,并且商店有移动项目的方法:
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
NSInteger beforeSectionCount = [store sectionCount];
[store moveObject:fromIndexPath toIndexPath:toIndexPath];
if (beforeSectionCount > [store sectionCount]
[self performSelector:@selector(deleteSection:) withObject:fromIndexPath: afterDelay:0.2]
}
- (void)deleteSection:(NSIndexPath *)indexPath {
[[self tableView] beginUpdates];
[[self tableView] deleteSections:[NSIndexSet indexSetWithIndex:[indexPath section]]
withRowAnimation:UITableViewRowAnimationFade];
[[self tableView] endUpdates];
}