Hide deleted row, from DataList without rebinding the DataSource

Question

Please consider these operations -

1. Bind a list of files in a DataList.
2. Once the user clicks delete LinkButton, delete the file, in ItemCommandEvent.
3. Since rebinding whole data is inefficient, I am simply hiding deleted row.

Following code displays files in a DataList. There is a delete button beside each row.

<asp:DataList ID="DataList1" OnItemCommand="DataList1_ItemCommand" runat="server">                
    <ItemTemplate>        
        <tr>
            <asp:Label Text='<%# Eval("ContainingFolder") as string + "\\" + Eval("FileName") as string %>' 
                Visible="false" ID="lblFullPath" runat="server" />
            <td><%# Eval("FileName") %></td>
            <td><%# Eval("ContainingFolder") %></td>
            <td><%# Eval("FileSize") %></td>
            <td><%# Eval("Modified") %></td>
            <td>
                <asp:LinkButton Text="Delete" ID="linkDelete" runat="server" />
            </td>
        </tr>            
    </ItemTemplate>
</asp:DataList>

In ItemCommand Event Handler this code deletes the selected file from this list.

protected void DataList1_ItemCommand(object source, DataListCommandEventArgs e)
{
    if (e.Item.ItemType != ListItemType.Item && e.Item.ItemType != ListItemType.AlternatingItem) return;

    var selectedItem = e.Item.FindControl("lblFullPath") as Label;

    e.Item.Visible = false;       //doesn't work     

    File.Delete(selectedItem.Text);
}

However e.Item.Visible = false does not hides the row. As a workaround found here, How to hide an item in datalist

I have wrapped contents inside a placeholder control.

<ItemTemplate>
    <asp:PlaceHolder ID="ph1" runat="server">
        <%--wrapped content--%>
    </asp:PlaceHolder>
</ItemTemplate>

And hiding the placeholder control -

protected void DataList1_ItemCommand(object source, DataListCommandEventArgs e)
{
    if (e.Item.ItemType != ListItemType.Item && e.Item.ItemType != ListItemType.AlternatingItem) return;

    var selectedItem = e.Item.FindControl("lblFullPath") as Label;
    //e.Item.Visible = false;
    e.Item.FindControl("ph1").Visible = false;
    File.Delete(selectedItem.Text);
}

Generally in asp.net hiding parent control hides all of its child controls.

But I am not able to understand,

Why hiding the parent control e.Item doesn't hide its containing elements, in case of DataList ? Can you please advise.

Thank you for your help.

EDIT: Updating more info about generating list of files to display in DataList.

• Generating fileList at runtime on button click, this list is not persistent, currently.

protected void btnFindDuplicates_Click(object sender, EventArgs e)
{
    DataList1.DataSource = FindDuplicates();
    DataList1.DataBind();
}

• In the event handler of delete Click, delete operation has been completed successfully.
• So, just to remove deleted item from the page, It would not be wise to regenerate the dataSource and bind this. Hiding seems more logical to me.

Answer 1

I created this sample using JQuery and PageMethods:

Result

ASPX

<script>
    $(function () {
        var $list = $("table[id*=myDataListID]");
        var $buttons = $("input:submit[id*=remove]", $list);

        $buttons.click(function (e) {
            e.preventDefault();

            if (!confirm("Are you sure?")) {
                return false;
            }

            var $self = $(this);
            var $jobID = $self.closest("tr").children().find("span[id*=jobID]");

            $buttons.prop("disabled", true);

            $.ajax({
                url: "<%: this.ResolveClientUrl("~/Topics/JQuery/Ajax/RemoveRowUsingJQueryAfterCallingService.aspx/Remove") %>",
                type: "POST",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                data: "{id: " + $jobID.text() + "}",
                async: true,
                cache: false,
                success: function () {
                    $buttons.prop("disabled", false);
                    $self.closest("tr").remove();
                },
                error: function (XHResponse, errorMessage, errorCode) {
                    $buttons.prop("disabled", false);
                    alert(errorMessage);
                }
            });
        });
    });
</script>

<asp:DataList runat="server" DataKeyField="job_id" DataSourceID="lds" ID="myDataListID">
    <HeaderTemplate>
        <tr>
            <th>
                &nbsp;
            </th>
            <th>
                ID
            </th>
            <th>
                Name
            </th>
        </tr>
    </HeaderTemplate>
    <ItemTemplate>
        <tr>
            <td>
                <asp:Button Text="Remove" runat="server" ID="remove" />
            </td>
            <td>
                <asp:Label Text='<%# Eval("job_id") %>' runat="server" ID="jobID" />
            </td>
            <td>
                <asp:Label ID="jobDesc" Text='<%# Eval("job_desc") %>' runat="server" />
            </td>
        </tr>
    </ItemTemplate>
</asp:DataList>

Code behind

[WebMethod]
public static void Remove(Int16 id)
{
    // simulate deleting the file
    Thread.Sleep(3000);
}

I just uploaded the full working example to my GitHub site