C＃Parallel.Invoke：操作被取消异常？

Question

嗨，

以下代码工作正常但有时我得到操作被取消异常？

 var _options = new ParallelOptions();
    _options.MaxDegreeOfParallelism = 5;
    Parallel.Invoke(_options, 
        () =>
            {
                //get list of item1 
                foreach (var item in lst_item1)
                {
                    // do some logic here
                }
            },
        () =>
        {
            //get list of item1 
            foreach (var item in lst_item2)
            {
                // do some logic here
            }
        },
          () =>
          {
        //get list of item1 
        foreach (var item in lst_item2)
        {
           // do some logic here
        }
    });
// continue logic code

非常感谢任何帮助！

此致