Question

I have a problem which is bothering me for three days.

On my web form I want to have a button, on which click I want to make dynamicly five text boxes in asp:PlaceHolder.

And I want, that values which I enter in this texBoxes, are saved even after postBack. With second button i want to store them.

I’ve read articles about lifecycle of page, viewState, IsPostBack,… a lot of articles of dynamically created controls, but I’m still not able to program this.

There are several ways I tried, but without success. Below is the last version of my “masterpiece”. Please help me to crate this task, because it makes me sick. Thanks, Martin

namespace DynamicCreate
{
    public partial class _Default : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.TextBox textBox;

        private TextBox[] my_dynamicTextBoxes = new TextBox[5];
        private string[] textBoxValues = new string[5];

        protected void Page_Load(object sender, System.EventArgs e)
        {
            btn_save_tb_values.Click += new EventHandler(save_btnClick);
            but_load_tb.Click += new EventHandler(creat_tb_btnClick);

            int i = 0;
            foreach (TextBox tb in my_dynamicTextBoxes)
            {
                if (ViewState["c_textBox" + i.ToString()] != null)
                {
                    tb.Text = (string)ViewState["c_textBox" + i.ToString()];
                    i++;
                }
                else
                {
                    textBox = new TextBox();
                    textBox.ID = "c_textBox" + i.ToString();
                    my_dynamicTextBoxes[i] = textBox;
                    i++;
                }
            }
        }

        protected void creat_tb_btnClick(object sender, EventArgs e)
        {
            int i = 0;
            foreach (TextBox neww in my_dynamicTextBoxes)
            {
                c_placeholder.Controls.Add(neww);
                c_placeholder.Controls.Add(new LiteralControl("<br>"));
                ViewState["c_textBox" + i.ToString()] = neww.Text;
                i++;
            }
        }

        protected void save_btnClick(object sender, EventArgs e)
        {
            for (int i = 0; i < 5; i++) {}
        }
    }
}



<form id="form1" runat="server">
        <div>
            <div>  <asp:PlaceHolder ID="c_placeholder" runat="server"></asp:PlaceHolder>    </div>
            <div>   <asp:Button runat="server" ID="but_load_tb"  Text="Dodaj Polja!!"/>       </div>
            <div>   <asp:Button runat="server" ID="btn_save_tb_values" Text="Izpisi Vrednosti!" />   </div
        </div>
    </form>

Answer 1

Here’s a simple example I came up with that will dynamically add 5 textboxes to a PlaceHolder when you click a “Create” button and will bring up the values when you click a “Save” button:

Default.aspx:

<asp:PlaceHolder ID="phButtons" runat="server" />
<asp:Button ID="btnCreate" Text="Create" runat="server" onclick="btnCreate_Click" />
<asp:Button ID="btnSave" Text="Save" runat="server" onclick="btnSave_Click" />

Default.aspx.cs:

protected void Page_Load(object sender, EventArgs e)
{
    if (ViewState["buttons"] != null)
        CreateButtons();
}

protected void btnCreate_Click(object sender, EventArgs e)
{
    ViewState["buttons"] = true;
    CreateButtons();
}

protected void btnSave_Click(object sender, EventArgs e)
{
    if (ViewState["buttons"] != null)
    {
        // Save the button information.
        foreach (Control ctl in phButtons.Controls)
        {
            string x;
            if (ctl is TextBox)
                x = (ctl as TextBox).Text;
        }
    }
}

private void CreateButtons()
{
    for (int iLoop = 0; iLoop < 5; iLoop++)
    {
        phButtons.Controls.Add(new TextBox() { ID = "txt" + iLoop });
    }
}