Question

这组代码显然是从服务器检索数据（从特定的几天开始）并在记事本中显示它们。我不知道为什么，它不断弹出消息框“char”，“money”和“nvarchar”。请原谅我这是一个愚蠢的问题

  SqlCommand objCmd = new SqlCommand("SELECT CONVERT(char(80), InvDate,3) AS InvDate,InvoiceNo,EmployerCode,TaxAmount + SubTotal AS Amount,'' AS Payment FROM Invoice WHERE (InvDate >= CONVERT(datetime, '"+dtpFrom.Text +"', 0 )) AND (InvDate <= CONVERT(datetime, '"+dtpTo.Text+"', 0))", objConn);

        SqlDataReader objReader;
        objReader = objCmd.ExecuteReader();

        System.IO.FileStream fs = new System.IO.FileStream("C:\\CMSExportedData\\Sales-" + DateTime.Now.ToString("dd-MM-yyyy") + ".txt", System.IO.FileMode.Create);
        System.IO.StreamWriter sw = new System.IO.StreamWriter(fs, System.Text.Encoding.Default);

        int count = 0;
        while (objReader.Read())
        {

            for (int i = 0; i < 5; i++)
            {
                if (!objReader.IsDBNull(i))
                {
                    string s;
                    s = objReader.GetDataTypeName(i);
                    MessageBox.Show(s);
                    if (objReader.GetDataTypeName(i) == "char")
                    {
                        sw.Write(objReader.GetString(i));
                    }
                    else if (objReader.GetDataTypeName(i) == "datetime")

                    {
                        sw.Write(objReader.GetSqlMoney(i).ToString());
                    }
                    else if (objReader.GetDataTypeName(i) == "nvarchar")
                    {
                        sw.Write(objReader.GetString(i));
                    }
                }
                if (i < 4)
                {
                    sw.Write("\t");
                }

            }
            count = count + 1;
            sw.WriteLine();

        }
        sw.Flush();
        fs.Close();
        objReader.Close();
        objConn.Close();
        MessageBox.Show(count + " records exported successfully.");
        this.Close();
    }

    private void groupBox1_Enter(object sender, EventArgs e)
    {

    }

    private void dtpTo_ValueChanged(object sender, EventArgs e)
    {

    }

Answer 1

您在循环中显示MessageBox，这就是您查看多个MessageBox数据类型的原因。如果您真的不想看到它们，只需删除以下行：

MessageBox.Show(s);

Answer 2

您的数据源包含Money类型的列。请注意，您不处理货币类型。这就是为什么其中一个messageBox包含'Money'文本。

无限循环的消息框

2 个答案: