Question

C#做登陆界面，comm.ExecuteReader()报错“至少一个参数没有被指定值”。求解！

access 2010数据库
下面是我的源代码！求大神支招！
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

namespace project_1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
string commandString = "select* from users where sname='"+textBox1.Text+"'and snum='"+textBox2.Text+"'";
string connectionString = "provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:/DB/DB2.accdb";
OleDbConnection conn = new OleDbConnection(connectionString);
conn.Open();
OleDbCommand comm = new OleDbCommand();
comm.Connection = conn;
comm.CommandText = commandString;
OleDbDataReader myDR = comm.ExecuteReader(); //这里报错！
if (myDR.HasRows)
MessageBox.Show("登录成功！");
else
MessageBox.Show("登录失败！");
conn.Close();
}
}
}

Answer 1

string commandString = "select* from users where sname='"+textBox1.Text+"'and snum='"+textBox2.Text+"'";

string sql =string.Format( "select * from users where sname= '{0}' and snum='{1}'"，textBox1.Text.ToString(),textBox2.Text.ToString());

试试