页面生命周期和文本框

在此处输入代码我在下拉列表使用自动回发更改项目时制作动态文本框。稍后我想在激活提交按钮时获取文本框的文本。但是当按钮激活时，文本框返回空白字符。问题一定是由于 页面寿命 .我应该使用什么技术来获取这些值？

    public class GuiOtherAuthors
    {
        public OtherAuthors[] tableOtherAuthors;
        public Label[] lblName;
        public TextBox[] txtName;
        public Label[] lblSurname;
        public TextBox[] txtSurname;
        public Label[] lblInstitution;
        public TextBox[] txtInstitution;
        public Label[] lblCountry;
        public TextBox[] txtCountry;
        public Label[] lblEmail;
        public TextBox[] txtEmail;
        public PlaceHolder PlaceHolder1 = new PlaceHolder();
        public Int32 NumberOfAutherOthos { set; get; }

        public void InitializeControls()
        {
            tableOtherAuthors = new OtherAuthors[NumberOfAutherOthos];
            lblName = new Label[NumberOfAutherOthos];
            txtName = new TextBox[NumberOfAutherOthos];
            lblSurname = new Label[NumberOfAutherOthos];
            txtSurname = new TextBox[NumberOfAutherOthos];
            lblInstitution = new Label[NumberOfAutherOthos];
            txtInstitution = new TextBox[NumberOfAutherOthos];
            lblCountry = new Label[NumberOfAutherOthos];
            txtCountry = new TextBox[NumberOfAutherOthos];
            lblEmail = new Label[NumberOfAutherOthos];
            txtEmail = new TextBox[NumberOfAutherOthos];
            for (int i = 0; i < NumberOfAutherOthos; i++)
            {
                lblName[i] = new Label();
                lblName[i].Text = "Name:";
                txtName[i] = new TextBox();
                lblSurname[i] = new Label();
                lblSurname[i].Text = "Surname:";
                txtSurname[i] = new TextBox();
                lblInstitution[i] = new Label();
                lblInstitution[i].Text = "Institution:";
                txtInstitution[i] = new TextBox();
                lblCountry[i] = new Label();
                lblCountry[i].Text = "Country:";
                txtCountry[i] = new TextBox();
                lblEmail[i] = new Label();
                lblEmail[i].Text = "Email:";
                txtEmail[i] = new TextBox();
            }
        }
        public PlaceHolder makeGUI()
        {
            int i = 0;
            int j = 1;

            for (i = 0; i < NumberOfAutherOthos; i++)
            {
                Label authorInformation = new Label();
                authorInformation.Text = "Information for Author " + j.ToString() + " :";
                lblName[i].Text = "Name:";
                lblSurname[i].Text = "Surname:";
                lblInstitution[i].Text = "Institution:";
                lblCountry[i].Text = "Country:";
                lblEmail[i].Text = "Email:";
                PlaceHolder1.Controls.Add(new LiteralControl("<table>"));
                PlaceHolder1.Controls.Add(new LiteralControl("<span style='"font-weight:bold;'" "));
                PlaceHolder1.Controls.Add(authorInformation);
                PlaceHolder1.Controls.Add(new LiteralControl("</span>"));
                PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>"));
                PlaceHolder1.Controls.Add(lblName[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td><td>"));
                PlaceHolder1.Controls.Add(txtName[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>"));
                PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>"));
                PlaceHolder1.Controls.Add(lblSurname[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td><td>"));
                PlaceHolder1.Controls.Add(txtSurname[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>"));
                PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>"));
                PlaceHolder1.Controls.Add(lblInstitution[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td><td>"));
                PlaceHolder1.Controls.Add(txtInstitution[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>"));
                PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>"));
                PlaceHolder1.Controls.Add(lblCountry[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td><td>"));
                PlaceHolder1.Controls.Add(txtCountry[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>"));
                PlaceHolder1.Controls.Add(new LiteralControl("<tr><td>"));
                PlaceHolder1.Controls.Add(lblEmail[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td><td>"));
                PlaceHolder1.Controls.Add(txtEmail[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("</td></tr>"));
                PlaceHolder1.Controls.Add(new LiteralControl("</table><br /> "));
                j++;
            }
            return PlaceHolder1;
        }
    }
The code is in c#
Thanks
 this is my page load:

    private GuiOtherAuthors gui = new GuiOtherAuthors();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            numberOfOtherAuthors = NumberOfOtherAuthors();
            if (!numberOfOtherAuthors.Equals(0))
            {
                gui.NumberOfAutherOthos = numberOfOtherAuthors;
                gui.InitializeControls(); //Initialize the textboes
                Panel1.Controls.Add(gui.makeGUI()); .. create my gui 
                setValueofOtherAuthors(numberOfOtherAuthors); //create object with value of textboxes
            }
        }
    }