怎样将datagridview中的数据保存到数据库中？？？

Question

   麻烦各位帮我看看下面的代码哪儿有问题，老是报错“未将对象引用设置到对象的实例”
                  public void baocun()
        {
            DataGridView mydataGridView = new DataGridView();
            mydataGridView = dataGridView1;            try
            {
                DataTable dt = (DataTable)mydataGridView.DataSource;
                foreach (DataRow dr in dt.Rows)
                {
                    switch (dr.RowState)
                    {
                        case DataRowState.Added:                            string xx = "";
                            string aa = "";                            string KZT = null;
                            string sql = "select columncode,columntype from KZT";
                            OleDbDataAdapter dat = new OleDbDataAdapter(sql, oleDbConnection1);
                            DataSet dst = new DataSet();
                            dat.Fill(dst, "tabledetail");
                            for (int i = 0; i < dst.Tables[0].Rows.Count; i++)
                            {
                                xx += "," + dst.Tables[0].Rows[i][0].ToString();
                                aa += "," + "'" + dr[i].ToString() + "'";
                            }                            string scmd = "insert into " + KZT + " ( " + xx + " ) values ( " + aa + ")";
                            OleDbCommand myCommand = new OleDbCommand(scmd, oleDbConnection1);
                            if (oleDbConnection1.State == System.Data.ConnectionState.Closed)
                            {
                                oleDbConnection1.Open();//打开数据库连接
                            }
                            myCommand.ExecuteNonQuery();
                            //判断连接是否需要关闭
                            if (oleDbConnection1.State == System.Data.ConnectionState.Closed)
                            {
                                //oleDbConnection1.Close();//关闭
                            }
                            break;
                    }
                    MessageBox.Show("保存数据成功!");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("保存数据失败，请重试!" + ex.Message);
                return;
            }
        }

Answer 1

你单步调试一下，看是哪一行出错，若是ＳＱＬ语句有问题，把它打印出来后到pl/sql里执行一下就知道哪里错了

Answer 2

报错是：foreach (DataRow dr in dt.Rows) 中的 dt.Rows 对象没有实例化

Answer 3

报错是：foreach (DataRow dr in dt.Rows) 中的 dt.Rows 对象没有实例化

Answer 4

你这个是VS.Net(C#)程序啊，问题在于下面这句啊
DataTable dt = (DataTable)mydataGridView.DataSource;
mydataGridView.DataSource不能强制转换成DataTable吧foreach (DataRow dr in dt.Rows)语法是对的，我们这么用都没有问题
        /// <summary>
        /// 在DataTable中根据指定的字段和其值返回第一个符合的DataRow，找不到匹配的行则返回null
        /// </summary>
        public static DataRow FindRow(ref DataTable dataTab, string colName, string strVal)
        {
            bool isFound = false;
            DataRow row2 = null;
            foreach (DataRow row1 in dataTab.Rows)
            {
                if (row1[colName].ToString() == strVal)
                {
                    isFound = true;
                    row2 = row1;
                    break;
                }
            }
            if (isFound)
                return row2;
            else
                return null;
        }