c#做的管理系统出现的问题，帮忙解决下吧，我快纠结死了
private void button1_Click(object sender, EventArgs e)
  {
  if (this.textBox1.Text == "" || this.textBox2.Text == "")
  {
  MessageBox.Show("用户名或密码不能为空！", "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
  this.textBox1.Focus();
  }
  else
  {
  string strcon = "Server=(local);Integrated Security=true;database=stu_info_manage";
  try
  {
  SqlConnection conn = new SqlConnection(strcon);
  conn.Open();
  string str = "select * from user_info where user_name='" + this.textBox1.Text.Trim() + "'";
  SqlCommand cmd = new SqlCommand(str, conn);
  SqlDataReader read = cmd.ExecuteReader();
  while (read.Read())
  {
  if (this.textBox2.Text.Trim() == read.GetString(1))
  {
  this.Hide();
  Form3 newform3 = new Form3();
  newform3.Show();
  }
  else
  {
  MessageBox.Show("密码错误！");
  }
  }
  conn.Close();
  }
  catch (Exception ex)
  {
  MessageBox.Show(ex.Message);
  }
  }
  }
这是我做的登陆界面出现的问题。按照数据库里添加的user_name和user_psw输入。总显示密码错误。

------解决方案--------------------
我建议你 sql 语句这样

C# code

string str = "select count(*) from user_info where user_name='" + this.textBox1.Text.Trim() + "' and 密码列='" + this.textBox2.Text.Trim() + "'";