这是为了按索引展开行:

@property (nonatomic) NSIndexPath *expandIndexPath;
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath*)indexPath
{
if ([indexPath isEqual:self.expandedIndexPath])
    return 100;

return 44;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSMutableArray *modifiedRows = [NSMutableArray array];
if ([indexPath isEqual:self.expandIndexPath]) {
    [modifiedRows addObject:self.expandIndexPath];
    self.expandIndexPath = nil;
} else {
    if (self.expandedIndexPath)
        [modifiedRows addObject:self.expandIndexPath];

    self.expandIndexPath = indexPath;
    [modifiedRows addObject:indexPath];
}

// This will animate updating the row sizes
[tableView reloadRowsAtIndexPaths:modifiedRows withRowAnimation:UITableViewRowAnimationAutomatic];

// Preserve the deselection animation (if desired)
[tableView selectRowAtIndexPath:indexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ViewControllerCellReuseIdentifier];
    cell.textLabel.text = [NSString stringWithFormat:@"I'm cell %ld:%ld", (long)indexPath.section, (long)indexPath.row];

return cell;
}

BOOL flag;

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    flag = !flag;
    [tableView beginUpdates];
    [tableView reloadRowsAtIndexPaths:@[indexPath] 
                     withRowAnimation:UITableViewRowAnimationAutomatic];
    [tableView endUpdates];
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return YES == flag ? 20 : 40;
}

获取所选行的indexpath。重新加载表。在UITableViewDelegate的highightforrowatindexpath方法中，将所选行的高度设置为不同的高度，对于其他的则返回正常的行高度

这是为了按索引展开行:

@property (nonatomic) NSIndexPath *expandIndexPath;
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath*)indexPath
{
if ([indexPath isEqual:self.expandedIndexPath])
    return 100;

return 44;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSMutableArray *modifiedRows = [NSMutableArray array];
if ([indexPath isEqual:self.expandIndexPath]) {
    [modifiedRows addObject:self.expandIndexPath];
    self.expandIndexPath = nil;
} else {
    if (self.expandedIndexPath)
        [modifiedRows addObject:self.expandIndexPath];

    self.expandIndexPath = indexPath;
    [modifiedRows addObject:indexPath];
}

// This will animate updating the row sizes
[tableView reloadRowsAtIndexPaths:modifiedRows withRowAnimation:UITableViewRowAnimationAutomatic];

// Preserve the deselection animation (if desired)
[tableView selectRowAtIndexPath:indexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ViewControllerCellReuseIdentifier];
    cell.textLabel.text = [NSString stringWithFormat:@"I'm cell %ld:%ld", (long)indexPath.section, (long)indexPath.row];

return cell;
}

只是一个提示，像我这样的人搜索添加“更多细节”自定义单元格。

[tableView beginUpdates];
[tableView endUpdates];

做了一个出色的工作，但不要忘记“裁剪”单元格视图。 从界面构建器中选择单元格->内容视图->从属性检查器中选择“剪辑子视图”

而不是beginUpdates()/ endpdates()，建议调用现在是:

tableView.performBatchUpdates(nil, completion: nil)

关于beginUpdates/ endpdates，苹果说:“尽可能使用performBatchUpdates(_:completion:)方法而不是这个方法。”

参见:https://developer.apple.com/documentation/uikit/uitableview/1614908-beginupdates