问didselectrowatindexpath，选择和取消选择Tableview中的行

EN

// This variable needs to be declared in a place where your data source can get it
NSMutableIndexSet *selected;

// You need to initialize it in the designated initializer, like this:
selected = [[NSMutableIndexSet alloc] init];

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
    }
    if ([selected containsIndex:indexPath.row]) {
        [cell setAccessoryType:UITableViewCellAccessoryCheckmark];
    } else {
        [cell setAccessoryType:UITableViewCellAccessoryNone];
    }
    // Do the rest of your code
    return cell;
}