System.InvalidOperationException:ExecuteReader:尚未初始化Connection属性

Question

protected void Button3_Click(object sender, EventArgs e)
{
 cn.Open();

 SqlCommand cmd = new SqlCommand("select top '"+Label4.Text+"' * from qb_vb where marks=1");

 SqlDataReader dr1 = cmd.ExecuteReader();

if (dr1.Read())
 {
  Label8.Text = dr1["quest"].ToString();
  Label9.Text = dr1["ans1"].ToString();
 }
cn.Close();

}

Answer 1

您需要将命令与您打开的连接相关联:

cn.Open();
SqlCommand cmd = new SqlCommand("select top '"+Label4.Text+"' * from qb_vb where marks=1");
cmd.Connection = cn; // <------ THIS MUST BE ADDED
SqlDataReader dr1 = cmd.ExecuteReader();
if (dr1.Read())
{
    Label8.Text = dr1["quest"].ToString();
    Label9.Text = dr1["ans1"].ToString();
}
cn.Close();