开/关编辑模式

#pragma mark----1. 开/关编辑模式

- (void)setEditing:(BOOL)editing animated:(BOOL)animated{
   
    [super setEditing:editing animated:animated];
    //利用系统编辑按钮 控制 tableView 编辑状态
    [self.myTableView setEditing:editing animated:animated];
}
#pragma mark----2.  询问编辑行是否需要编辑
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath{
    return YES;
}
#pragma mark----3.设置 cell 的编辑样式
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath{
  
    return UITableViewCellEditingStyleDelete;
}
#pragma mark-- 4.判断状态 执行 删除操作

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{
     // 编辑操作的过程就是 先删除数据 然后同步视图
    NSString *key = [[Danli shareDanli].allKeysArray objectAtIndex:indexPath.section];
    NSMutableArray *array= [[Danli shareDanli].studentDic objectForKey:key];
    [array removeObjectAtIndex:indexPath.row];
    [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath, nil] withRowAnimation:UITableViewRowAnimationRight];
    if (array.count == 0) {
        [[Danli shareDanli].studentDic removeObjectForKey:key];
        [[Danli shareDanli].allKeysArray removeObjectAtIndex:indexPath.section];
       
        [tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationFade];
       
    }

}