for (int i = 0; i < this.Controls.Count; i++)
        {
            foreach (Control control in this.Controls[i].Controls)
            {
                if (control is TextBox)
                {
                    TextBox txt = (TextBox)control;
                    if (txt.Text == "")
                    {
                        Response.Write("<script>alert('空的');</script>");
                    }
                }
            }
        }

------解决方案--------------------

探讨


C# code

        for (int i = 0; i < this.Controls.Count; i++)
       {
           foreach (Control control in this.Controls[i].Controls)
           {
               if (control is TextBox)
  ……