Object reference not set to an instance of an object. (未将对象引用到实例)

Question

在将对象序列化的时候，本地测试没问题。在iis6下就出现Object reference not set to an instance of an object. 请大虾们帮忙看看. 代码如下: protected void btnsubmit_Click(object sender, EventArgs e)        {             Jisuangongshi jisuangongs = new Jisuangongshi();             jisuangongs.Zbgs = txtzb.Text;            jisuangongs.Djgs = txtdj.Text;            jisuangongs.Jbgs = txtjb.Text;             save(jisuangongs);        }         public void save(Jisuangongshi lstjsuan)         {            FileStream filestream = null;            try             {                                filestream = new FileStream("ProduceCheck.files", FileMode.Create);                BinaryFormatter bf = new BinaryFormatter();                bf.Serialize(filestream, lstjsuan);            }            catch (Exception ex)             {                            }            finally             {                filestream.Close();            }                        Response.Write("<script>alert('修改成功!');window.location.href='ParaManager.aspx';</script>");        } [Serializable]    public class Jisuangongshi    {        private string _djgs;         public string Djgs        {            get { return _djgs; }            set { _djgs = value; }        }         private string _zbgs;         public string Zbgs        {            get { return _zbgs; }            set { _zbgs = value; }        }         private string _jbgs;         public string Jbgs        {            get { return _jbgs; }            set { _jbgs = value; }        }

Answer 1

filestream = new FileStream("ProduceCheck.files", FileMode.Create);

这里创建 FileStream 的时候抛出了异常,

你把异常吃掉了,

catch (Exception ex) 
{
      throw ex; // 这里出现的异常会告诉你你无权县创建FileStream,或者  ProduceCheck.files 已存在等错误.
}

所以,异常会从这里抛出,因为 filestream == null,系统报告 NullReferenceException.

finally
{
                filestream.Close();
}

Answer 2

至少说明哪一行报的错啊

Answer 3

 遇到过一种情况是dll 和aspx页面不匹配造成的