Can not get textbox value inside datalist - asp.net

Question

I am trying to get the value of textbox "Qty" inside a datalist. It does not work. What is wrong? I have both the CartItem label and the datelist inside the ajax updatepanel. Thanks for any help. Here is my code:
<asp:Label ID="CartItems" runat="server" Text="CartItem"></asp:Label>
<br />
<asp:DataList ID="DataList1" runat="server" CellPadding="10"
DataKeyField="product_id" DataSourceID="SqlDataSource1" RepeatColumns="2">
<ItemTemplate>
<asp:Label ID="product_id" runat="server"
Text='<%# Eval("product_id") %>' /><br/>
<asp:Label ID="product_name" runat="server"
Text='<%# Eval("product_name") %>' />
<br />
Qty
<br/>
<asp:TextBox ID="Qty" runat="server"></asp:TextBox>
<asp:Button ID="ButtonAddToCart" runat="server" Text="Add to Cart"
onClick="ButtonAddToCart_Click"/>
<br />
</ItemTemplate>
</asp:DataList>
and here is the button click event. The CartItem has null value:
protected void ButtonAddToCart_Click(object sender, EventArgs e)
{
CartItem.Text = DataList1.FindControl("Qty").ToString();
}

Answer 1

TextBox Qty = (TextBox)DataList1.FindControl("Qty");
if(Qty != null)
{
CartItem.Text =Qty.Text;
}

Answer 2

You can use NamingContainer or Parent to access sibling controls
protected void ButtonAddToCart_Click(object sender, EventArgs e)
{
var button = sender as Button;
var textbox = button.NamingContainer.FindControl("Qty") as TextBox;
CartItem.Text = textbox.Text;
}

Answer 3

I prefer you to use item_command event of the datalist
do some think like this.
<asp:Label ID="CartItems" runat="server" Text="CartItem"></asp:Label>
<br />
<asp:DataList ID="DataList1" runat="server" CellPadding="10" DataKeyField="product_id" DataSourceID="SqlDataSource1" RepeatColumns="2">
<ItemTemplate>
<asp:Label ID="product_id" runat="server"
Text='<%# Eval("product_id") %>' /><br/>
<asp:Label ID="product_name" runat="server"
Text='<%# Eval("product_name") %>' />
<br />
Qty
<br/>
<asp:TextBox ID="Qty" runat="server"></asp:TextBox>
<asp:Button ID="ButtonAddToCart" runat="server" Text="Add to Cart" CommandName="addtocart2" OnCommand="DataList1_ItemCommand"
/>
<br />
</ItemTemplate>
</asp:DataList>
Here is the item_command event that works.
public void DataList1_ItemCommand(object source, System.Web.UI.WebControls.CommandEventArgs e){
TextBox qtytxtbox = DataList1.FindControl("Qty") as TextBox;
}

Answer 4

You can do like this
protected void ButtonAddToCart_Click(object sender, EventArgs e)
{
Button ButtonAddToCart= (Button)sender;
DataListItem item = (DataListItem)ButtonAddToCart.NamingContainer;
var textbox = (TextBox)item.FindControl("Qty");
}

Answer 5

try this one
TextBox txtquantity = (TextBox)(e.Item.FindControl("Qty"));
simply use this......You will get the value in txtquantity