Question

The .Text on add is giving the error, I believe I have the right assemblies in place.

StringCollection sc = new StringCollection();

for (int i = 1; i <= 2; i++)
{
    //extract the TextBox values
    string txt1 = ((TextBox)Page.FindControl("TextBox1" + i.ToString())).Text;
    string txt2 = ((TextBox)Page.FindControl("TextBox2" + i.ToString())).Text;
    string txt3 = ((TextBox)Page.FindControl("TextBox3" + i.ToString())).Text;
    string txt4 = ((TextBox)Page.FindControl("TextBox4" + i.ToString())).Text;
    string txt5 = ((TextBox)Page.FindControl("TextBox5" + i.ToString())).Text;
    string txt6 = ((TextBox)Page.FindControl("TextBox6" + i.ToString())).Text;
    string txt7 = ((TextBox)Page.FindControl("TextBox7" + i.ToString())).Text;
    string txt8 = ((TextBox)Page.FindControl("TextBox8" + i.ToString())).Text;
    string txt9 = ((TextBox)Page.FindControl("TextBox9" + i.ToString())).Text;

    sc.Add(txt1.Text, txt2.Text, txt3.Text, txt4.Text, txt5.Text, txt6.Text, txt7.Text, txt8.Text, txt9.Text);
}

    InsertRecords(sc);

Answer 1

You are basically calling string.Text since the type of txt1, txt2, etc is string, hence the error. But note that you are already calling .Text on the TextField control so what you probably intend to do is:

sc.AddRange(new string[]{txt1, txt2, txt3, ...});