求各位大神帮助，阅读器关闭时尝试调用 Read 无效。

[weixin_38407556]

private void button1_Click(object sender, EventArgs e)
{
String user = stusno.Text.ToString();
String pwd = stupwd.Text.ToString();
SqlConnection con = new SqlConnection(sqlconn);
con.ConnectionString = @"server=DESKTOP-JGMS3CE\SQLEXPRESS;database=SMS;uid=sa;pwd="*********";
con.Open();
SqlCommand com = new SqlCommand("select * from Manage",con);
SqlDataReader read = com.ExecuteReader();
while(read.Read()){ ///////就是这一行报错
if(user==null||pwd==null){
MessageBox.Show("请输入用户名或密码");
break;
}
else if(user == read[0].ToString() && pwd == read[1].ToString())
{

Students getsl = new Students();
getsl.ShowDialog();


return;
}
read.Close();
con.Close();

[exception92]

如果 if,else if 中的条件都不满足 就会 执行read.close。 应该把close 放到 while 循环外边。

[本人QQ-554433626]

把 read.Close();和con.Close();放在while()外部