private void btnInput_Click(object sender, EventArgs e) {    if (opFile.ShowDialog() != DialogResult.OK)    //判断用户点击 确定 还是 取消,不点确定,则返回程序     {           return;     }     using(FileStream FStream = File.OpenRead(opFile.FileName))        //打开文件进行读取     {        //定义字符编码为GB2312        using (StreamReader stremReader = new StreamReader(FStream,Encoding.GetEncoding("GB2312")))        　　{        using (SqlConnection conn = new SqlConnection(@"server=.;database=mytest;uid=sa;pwd=gao"))          {             conn.Open();             using (SqlCommand cmd = conn.CreateCommand())             {               cmd.CommandText = "insert into T_Age(Name,Age) values(@N,@A)";               string line = null;               while ((line = stremReader.ReadLine()) != null)    //读取文本中一行数据,当不为空时               {                 string[] strs = line.Split('-');        // 按"-"符分割字符串                 string name = strs[0];                 int age = Convert.ToInt32(strs[1]);                 cmd.Parameters.Clear(); //参数不能重复添加,在while中一直用的是这个SqlCommand对象         　　　　 cmd.Parameters.Add(new SqlParameter("@N", name));                 cmd.Parameters.Add(new SqlParameter("@A", age));                 cmd.ExecuteNonQuery();                 }               }           }    　　}        MessageBox.Show("导入成功！");     }  }