TextBox    tt = new TextBox ();
            tt.ID = "te" + sum.ToString();
            tt.Style["width"] = "60px";
            tt.Style["height"] = "60px";
            if (sum == 1)
            {
                tt.Style["Left"] = "200px";
            }
            else
            {
                tt.Style["Left"] = "300px";
            }
            
            tt.Style["Top"] = "400px";
            tt.Visible = true;
           
          this.form1.Controls.Add(tt);//提示这句出错,控件包含代码块(即 <% ... %>),因此无法修改控件集合。