嘗試刪除單元格和節時，UITableView崩潰

Question

我一直在努力創建一個UITableView，其內容從NSUserDefaults對象加載。 但是，每當我嘗試刪除一個單元格/節時，程序崩潰並吐出以下內容：

*** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-1912.3/UITableView.m:1030
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of sections.  The number of sections contained in the table view after the update (2) must be equal to the number of sections contained in the table view before the update (3), plus or minus the number of sections inserted or deleted (0 inserted, 0 deleted).

無論我多少讀過這個錯誤並嘗試修復它，我都被困在這里過去幾個小時。 這是我的方法，當用戶點擊“刪除”按鈕時調用該方法：

 (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        //[[[NSUserDefaults standardUserDefaults] objectForKey:@"rawArray"] removeObjectAtIndex:indexPath.row];
        //[[[NSUserDefaults standardUserDefaults] objectForKey:@"rawDates"] removeObjectAtIndex:indexPath.row];

        NSMutableArray *rawArray = [[NSUserDefaults standardUserDefaults] objectForKey:@"rawArray"];
        NSMutableArray *rawDates = [[NSUserDefaults standardUserDefaults] objectForKey:@"rawDates"];

        [rawArray removeObjectAtIndex:indexPath.row];
        [rawDates removeObjectAtIndex:indexPath.row];

        [[NSUserDefaults standardUserDefaults] setObject:rawArray forKey:@"rawArray"];
        [[NSUserDefaults standardUserDefaults] setObject:rawDates forKey:@"rawDates"];

        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationRight];
        [tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationRight];

    }    
}

以下是用於確定行數和單元格數的方法：

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return [[[NSUserDefaults standardUserDefaults] arrayForKey:@"rawDates"] count];
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section{

    return [[[NSUserDefaults standardUserDefaults] arrayForKey:@"rawDates"] objectAtIndex:section];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return 1;
}

那里的最后一個方法返回一個，因為到目前為止，我計划每個部分只有一個單元格。 感謝您抽出寶貴時間來看看這里，我真的希望您能幫助我！ ：/

Answer 1

查看行和節的批量插入，刪除和重新加載

基本上你需要調用這些方法

- (void)insertSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation;
- (void)deleteSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation;
- (void)reloadSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation;

- (void)insertRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation: (UITableViewRowAnimation)animation;
- (void)deleteRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation: (UITableViewRowAnimation)animation;
- (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation;

之間

- (void)beginUpdates;
- (void)endUpdates;

例如

[tableView beginUpdates];
[tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationRight];
[tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationRight];
[tableView endUpdates];

您的dataSource還需要在調用endUpdates時反映更改

---

就個人而言，我喜歡創建一個類別來給出一個基於塊的包裝器

1. 阻止我忘記調用endUpdates
2. 它允許縮進看起來正確/自動

UITableView類別

@interface UITableView (PSAdditions)

- (void)ps_updates:(void (^)(void))updateBlock;

@end

@implementation UITableView (PSAdditions)

- (void)ps_updates:(void (^)(void))updateBlock;
{
    [self beginUpdates];
    if (updateBlock) { updateBlock(); }
    [self endUpdates];
}

這看起來像這樣

[tableView ps_updates:^{
    [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationRight];
    [tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationRight];
}];