you need to bind the cartId to the linkbutton onItemDataBound and then access it onItemCommand, I have modified code for you, give this a go
<asp:Repeater ID="Cartridges" runat="server" onitemcommand="Repeater_OnItemCommand" OnItemDataBound="Repeater_OnItemDataBound">
<ItemTemplate>
<p class="cartprice"><%#String.Format("{0:C}", Eval("Price"))%></p>
<hr class="hr4" />
<p class="cartqty">QTY <asp:TextBox ID="cartQty" Text="0" runat="server"></asp:TextBox> </p>
<div class="cartbuy2"><asp:LinkButton ID="buy" runat="server" CommandName="AddtoCart" Text="Buy"></asp:LinkButton></div>
your onItemdatabound should look like this
protected void Repeater_OnItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
//your code...
LinkButton add = (LinkButton)e.Item.FindControl("buy");
add.CommandArgument = cartID.ToString();
}
and then you can access the text box on item command like this
protected void Repeater_OnItemCommand(object source, RepeaterCommandEventArgs e)
{
if (e.CommandName == "AddtoCart")
{
LinkButton btnEdit = (LinkButton)e.CommandSource;
if (btnEdit != null)
{
string editId = btnEdit.CommandArgument;
string text = ((TextBox)e.Item.FindControl("cartQty")).Text;
//do some stuff with your cartid and quantity
}
}
}
You can also extend your code with edit/delete command arguments by adding more linkbuttons and binding them to the correct command and then accessing them in on item command
Thanks