How to do AsyncPostBackTrigger for the LinkButton in the Repeater

In my page, I have an LinkButton inside repeater, but the UpdatePanel cannot find the LinkButton to AsyncPostBackTrigger.

Here is mycode.aspx

<asp:ScriptManager ID="Test1" runat="server" />
<asp:UpdatePanel ID="TestUpdate" runat="server" UpdateMode="Always">
<ContentTemplate>
<table width="100%">
<tr valign="top">
    <td width="50%">
        <asp:Repeater ID="productList" runat="server" onitemcommand="productList_ItemCommand">
        <HeaderTemplate>
        <ul type="disc">
        </HeaderTemplate>
        <ItemTemplate>
        <li>
            <asp:Label id="L1" runat="server" Text='<%# Eval("productName") %>'></asp:Label><br />
            Price:
            <asp:Label runat="server" Text='<%# Eval("productPrice") %>' ></asp:Label>&nbsp;Bath<br />
            <img alt="" src="Images/product/product<%# Eval("productID") %>.png" style="width: 200px; height: 130px" /><br />
            <asp:TextBox ID="num_product" runat="server" Text="0"></asp:TextBox><br />
            <asp:LinkButton ID="order_button" runat="server"><img alt="" src="~/Images/button/order.png" /></asp:LinkButton>
        </li>
        </ItemTemplate>
        <FooterTemplate>
        </ul>
        </FooterTemplate>
        </asp:Repeater> 
    <td>
    <span class="labelText">Order list</span>
        <asp:BulletedList ID="orderList" runat="server" BulletStyle="Numbered">
        </asp:BulletedList> 
    </td>
</tr>
</table>
</ContentTemplate>
</asp:UpdatePanel>

Here is mycode.aspx.cs

protected void productList_ItemCommand(object source, RepeaterCommandEventArgs e)
    {
        //button
        /*LinkButton btn = new LinkButton();
        btn.ID = "order_button";
        btn.Click += LinkButton1_Click;
        Test1.RegisterAsyncPostBackControl(btn);*/

        LinkButton btn = (LinkButton)e.Item.FindControl("order_button");
        btn.Click += LinkButton1_Click;
        Test1.RegisterAsyncPostBackControl(btn);

            /*AsyncPostBackTrigger trigger = new AsyncPostBackTrigger();
            trigger.ControlID = btn.ClientID;
            trigger.EventName = "Click";
            TestUpdate.Triggers.Add(trigger);*/

    }
   protected void LinkButton1_Click(object sender, EventArgs e)
    {
        //string name = ProductName1.Text.ToString();
        //int price = System.Convert.ToInt32(ProductPrice1.ToString(), 10);
        //int number = System.Convert.ToInt32(TextBox1.ToString(),10);
        //orderList.Items.Clear();
        //orderList.Items.Add(new ListItem(name));
        //ListItem product1 = new ListItem();
        //product1.Text = name;
        orderList.Items.Add("test");
    }

I tried many methods, but the page is still refresh. Do you have any suggestion?

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

Inside ItemCreated event of the Repeater control register the button with ScriptManager.

//Inside ItemCreatedEvent
ScriptManager scriptMan = ScriptManager.GetCurrent(this);
LinkButton btn = e.Item.FindControl("order_button") as LinkButton;
if(btn != null)
{
    btn.Click += LinkButton1_Click;
    scriptMan.RegisterAsyncPostBackControl(btn);
}

Method 2

I had similar problem, but I didn’t want to update the whole repeater, only a content outside of the repeater… so what I did was

1. Add the repeater

<asp:Repeater ID="productList" runat="server">
  <!-- my repeater -->
<asp:Repeater>

2. Add the Update Panel with the updatable content, and the trigger

<asp:UpdatePanel ID="up" runat="server">
    <ContentTemplate>
        <!-- when click on repeater's links, this content will be updated -->
    </ContentTemplate>
    <Triggers>
        <!-- trigger will be the repeater's links/btn that generate postback -->
        <asp:AsyncPostBackTrigger ControlID="productList" />
    </Triggers>
</asp:UpdatePanel>

Method 3

Adding the following attribute to the page directive containing the repeater and linkbutton will also work:

<%@ page ClientIDMode="AutoID" %>

I had a control that needed to work both asynchronously and full postback, so using the ScriptManager.RegisterAsyncPostBackControl would not work for me. By enclosing the control (which contained a repeater and linkbutton) inside of an UpdatePanel, the linkbutton would cause an asynchronous postback. With no updatepanel, the linkbutton would cause a fullpostback.

Hope this helps someone else.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0