填充：SelectCommand.Connection 属性尚未初始化 C#

Question

public partial class WebForm1 : System.Web.UI.Page
{
    SqlConnection con=new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True");
    SqlDataAdapter da = new SqlDataAdapter();
    SqlCommand cmd = new SqlCommand();
    DataTable dt = new DataTable();


    protected void Page_Load(object sender, EventArgs e)
    {
    cmd.CommandText="select id from regtb where id="+Session["id"];
    da.SelectCommand = cmd;
    da.Fill(dt);
    if(dt.Rows.Count>0)
    {
        Response.Redirect("userlogin.aspx");

    }

    }

What is wrong with this code? can anybody help me on this i am getting this error and i dont know how to correct this.

Answer 1

You will need to open your SqlConnection and then assign it to the SqlCommand:

                con.Open();
                cmd.Connection = con;