CODEWITHSUNDEEP
asp.netdata-binding
Bob Tway
Bob Tway

Reputation: 9603

Repeater databound loses data & event on postback - is there a best practice solution?

Currently struggling with a problem that I've encountered variations on in the past. At the moment a worthwhile solution escapes me, but it seems such an obvious issue that I can't help wondering whether or not there's a "best practice" approach I should adopt.

Without code, here's the issues in a nutshell:

I've confirmed that this is the problem because if you provide the repeater with some static data on page load, everything works fine. But of course that's no use because it has to be populated dynamically.

Is there a commonly approved way round this headache? I can store the data in session and re-use it on page load, but it seems terribly clumsy.

Cheers, Matt

Upvotes: 1

Views: 2095

Answers (2)

ChrisLively
ChrisLively

Reputation: 88044

If any of your controls are created dynamically, then they have to be recreated during post back in order for the events etc to get hooked back up.

If this is the case, take a look at a control built by a guy named Denis Bauer. We use this with just some slight modifications and it's perfect.

Upvotes: 2

Andy Rose
Andy Rose

Reputation: 16974

If the event is being fired by a button within a repeater then this would bubble up to the repeaters ItemCommand event. Using a buttons CommandName and CommandArgument parameters you can then identify which button was clicked and act accordingly. Below is some basic markup and code behind to demonstrate the approach:
HTML:

<asp:Repeater ID="rptTest" runat="server" onitemcommand="rptTest_ItemCommand" 
    onitemdatabound="rptTest_ItemDataBound">
    <ItemTemplate>
        <p>
            <asp:Button ID="btnTest" runat="server" />
        </p>
    </ItemTemplate>
</asp:Repeater>
<asp:Button ID="btnLoad" runat="server" Text="Load" onclick="btnLoad_Click" />

Code behind events:

protected void rptTest_ItemDataBound(object sender, RepeaterItemEventArgs e)
{

    Button button = (Button)e.Item.FindControl("btnTest");
    button.Text = string.Format("Button {0}", e.Item.DataItem.ToString());
    button.CommandName = e.Item.ItemIndex.ToString();
}

protected void rptTest_ItemCommand(object source, RepeaterCommandEventArgs e)
{
    Response.Write(string.Format("Postback from button {0}", e.CommandName));
}

protected void btnLoad_Click(object sender, EventArgs e)
{
    List<int> list = new List<int>();
    list.Add(1);
    list.Add(2);
    list.Add(3);
    list.Add(4);
    rptTest.DataSource = list;
    rptTest.DataBind();
}

Hopefully i've understood the problem and this helps.

Upvotes: 3

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