You can use for loop to create controls in the back end.
Usually you can get the no of controls you want in dropdownlist and then with that number you can create controls in the backend dynamically.
I have attached a sample example .. You can check that out
.aspx page
<body>
<form id="form1" runat="server">
<asp:Panel ID="Panel1" runat="server">
</asp:Panel>
<div>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
<asp:Button ID="Button1" runat="server"
Text="Button" OnClick="Btn_Click" />
</form>
</body>
c# code
protected void Page_Load(object sender, EventArgs e)
{
for (int i = 0; i < 5; i++)
{
Panel panel = new Panel();
TextBox txt = new TextBox();
txt.ID = "Textbx" + i;
panel.Controls.Add(txt);
Panel1.Controls.Add(panel);
}
}
protected void Btn_Click(object sender, EventArgs e)
{
Label1.Text = "";
for (int i = 0; i < 5; i++)
{
TextBox txt=(TextBox)Page.FindControl("Textbx"+i);
Label1.Text =Label1.Text+ txt.Text + "<br />";
}
}
Over here since you need only the image path you dont have to upload it. You can get the filename.
I hope this is what your query is..