panel动态增加的控件怎么 取值问题？

//成型时间控件
            for (int i1 = 0; i1 <shuliang; i1++)
            {
                DateTimePicker chengxingshijian = new DateTimePicker();
                chengxingshijian.Name = "Chengxingshijian" + i1.ToString();
                chengxingshijian.CustomFormat = "YYYY-MM-DD";
                chengxingshijian.Value = DateTime.Now;
                chengxingshijian.CustomFormat = "YYYY-MM-DD";
                chengxingshijian.Left = left;
                chengxingshijian.Top = i1 * (top * 3 + chengxingshijian.Height*3) + top;
                chengxingshijian.Width = 130;
                panel1.Controls.Add(chengxingshijian);
            }

            //龄期
            for (int i3 = 0; i3 < shuliang; i3++)
            {
                TextBox lingqi = new TextBox();
                lingqi.Name = "lingqi" + i3.ToString();
                lingqi.Text = lingqicb.Text.Trim();
                lingqi.ReadOnly = true;
                lingqi.Width = 60;
                lingqi.TextAlign = HorizontalAlignment.Center;
                lingqi.Left = left + 140;
                lingqi.Top = i3 * (top * 3 + lingqi.Height * 3) +top;
                panel1.Controls.Add(lingqi);
            }
      
            //抗压时间控件
            for (int i1 = 0; i1 < shuliang; i1++)
            {
                DateTimePicker kangyashijian = new DateTimePicker();
                kangyashijian.Name = "kangyashijian" + i1.ToString();
                DateTime dt = chengxingshijian.Value.Add(TimeSpan.Parse(lingqi.Text.Trim()));
                kangyashijian.Value = dt;
                kangyashijian.CustomFormat = "YYYY-MM-DD";
                kangyashijian.Left = left + 210;
                kangyashijian.Top = i1 * (top * 3 + kangyashijian.Height * 3) + top;
                kangyashijian.Width = 130;
                panel1.Controls.Add(kangyashijian);
            }
我要怎么取到上面两个动态增加控件的文本值？