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(1/3) ListView events, ItemDataBound, ItemCreated

Below are the screenshots about a user control that is using the .NET ListView control.

Display Record

The ListView control contains many different events. In these examples, the EDIT button, REMOVE button, ADD button, and SAVE button click events are handled respectively.

Of course, there are many ways of implementations to get the job done, as far as I believed, using these ItemDataBound, ItemEditing, ItemDeleting, ItemCanceling, ItemUpdating, and ItemInserting are the easiest way.

Before implementing the code, design the UI first.

<table>
<thead>
    <tr>
        <th><asp:Literal ID="LitHost" runat="server" /></th>
        <th><asp:Literal ID="LitPointsTo" runat="server" /></th>
        <th><asp:Literal ID="LitTtl" runat="server" /></th>
        <th><asp:Literal ID="LitActions" runat="server" /></th>
    </tr>
</thead>

<tbody>
    <asp:ListView ID="LstItems" runat="server">
        <LayoutTemplate>
            <tr id="itemPlaceHolder" runat="server" />
        </LayoutTemplate>
        <ItemTemplate>
            <tr>
                <td><asp:Literal ID="LitHost" runat="server" /></td>
                <td><asp:Literal ID="LitPointsTo" runat="server" /></td>
                <td><asp:Literal ID="LitTtl" runat="server" /></td>
                <td>
                    <asp:LinkButton CommandName="Edit" ID="BtnEdit" runat="server" />
                    <asp:LinkButton CommandName="Delete" ID="BtnRemove" runat="server" />
                </td>
            </tr>
        </ItemTemplate>
        <EditItemTemplate>
            <tr>
                <td><asp:TextBox ID="TxtHost" runat="server" /></td>
                <td><asp:TextBox ID="TxtPointsTo" runat="server" /></td>
                <td><asp:DropDownList ID="DdlTtl" runat="server" /></td>
                <td>
                    <asp:LinkButton CommandName="Update" ID="BtnSave" runat="server" />
                    <asp:LinkButton CommandName="Cancel" ID="BtnCancel" runat="server" />
                </td>
            </tr>
        </EditItemTemplate>
        <InsertItemTemplate>
            <tr>
                <td><asp:TextBox ID="TxtNewHost" runat="server" /></td>
                <td><asp:TextBox ID="TxtNewPointsTo" runat="server" /></td>
                <td><asp:DropDownList ID="DdlNewTtl" runat="server" /></td>
                <td><asp:LinkButton ID="BtnAdd" CommandName="Insert" runat="server" /></td>
            </tr>
        </InsertItemTemplate>
    </asp:ListView>
</tbody>
</table>

In the code-behind, we need to hook up the ItemDataBound event, and bind the data source.

LstItems.ItemDataBound += new EventHandler<ListViewItemEventArgs>(LstItems_ItemDataBound);

LstItems.DataSource = DnsCollection;
LstItems.DataBind();

It is more flexible to handle the ItemDataBound event in the code-behind than binding the data source in the UI.

protected void LstItems_ItemDataBound(object sender, ListViewItemEventArgs e)
{
    var item = e.Item;
    if (item.ItemType == ListViewItemType.DataItem)
    {
        var currentDnsRecord = (DnsRecordItem)(item as ListViewDataItem).DataItem;

        // When Displaying the items
        if (item.DataItemIndex != LstItems.EditIndex)
        {
            var litHost = item.FindControl<Literal>("LitHost");
            var litPointsTo = item.FindControl<Literal>("LitPointsTo");
            var litTtl = item.FindControl<Literal>("LitTtl");

            litHost.Text = currentDnsRecord.HostName;
            litPointsTo.Text = currentDnsRecord.PointsTo;
            litTtl.Text = currentDnsRecord.TimeToLive;
        }
        else
        {   // When rendering Edit item.
            var txtHost = item.FindControl<TextBox>("TxtHost");
            var txtPointsTo = item.FindControl<TextBox>("TxtPointsTo");
            var ddlTtl = item.FindControl<DropDownList>("DdlTTL");

            txtHost.Text = OldDnsRecord.HostName;
            txtPointsTo.Text = OldDnsRecord.PointsTo;
            BindDdlTimeToLive(ddlTtl, OldDnsRecord.TimeToLive);
        }
    }
}

If you are not quite sure the FindControl, please check my previous post, FindControl() Extention methods.

On the other hand, when you want to do something before ItemDataBound event, you can create this ItemCreated event handler.

LstItems.ItemCreated += new EventHandler<ListViewItemEventArgs>(LstItems_ItemCreated);

ItemCreated is happened when the ListView is created, and when the data items are bound to the control.
ItemCreated is raised before the ItemDataBound event.

protected void LstItems_ItemCreated(object sender, ListViewItemEventArgs e)
{
    var item = e.Item;

    if (item.ItemType == ListViewItemType.DataItem)
    {
    }
    else if (item.ItemType == ListViewItemType.InsertItem)
    {
    }
}

(2/5) ListView events, ItemInserting, ItemDeleting

Add Record

In order to have this ADD button work, what we need is to wire the events first in the page's code behind.

LstItems.ItemInserting += new EventHandler<ListViewInsertEventArgs>(LstItems_ItemInserting);

LstItems.ItemDeleting += new EventHandler<ListViewInsertEventArgs>(LstItems_ItemDeleting);

LstItems.InsertItemPosition = InsertItemPosition.LastItem;

And usually, we will have this insert template either in the first item of this ListView or the last item. In this example, it is in the last item.

Button "Add" click.

protected void LstItems_ItemInserting(object sender, ListViewInsertEventArgs e)
{
    if (!Page.IsValid)
    return;

    var txtNewHost = e.Item.FindControl<TextBox>("TxtNewHost");
    var txtNewPointsTo = e.Item.FindControl<TextBox>("TxtNewPointsTo");
    var ddlNewTtl = e.Item.FindControl<DropDownList>("DdlNewTTL");

    var host = txtNewHost.Text;
    var pointsTo = txtNewPointsTo.Text;
    var ttl = ddlNewTtl.SelectedValue;

    var result = AddNewRecord();
    if (result == Status.Ok)
    {
        // Rebind the ListView
    }
    else
    {
        // Do error handling
    }
}

Button "Remove" click.

protected void LstItems_ItemDeleting(object sender, ListViewInsertEventArgs e)
{
    var item = LstItems.Items[e.ItemIndex];

    var result = RemoveRecord();
    if (result == Status.Ok)
    {
        LstItems.EditIndex = -1;

        // Rebind the ListView
    }
    else
    {
        // Do error handling
    }
}

(3/3) ListView events, ItemEditing, ItemCanceling, ItemUpdating

Edit Record

Same for this Edit Record, Save Record and Cancel button click events.

Wire the events in the code-behind first.

LstItems.ItemEditing += new EventHandler<ListViewItemEventArgs>(LstItems_ItemEditing);
LstItems.ItemUpdating += new EventHandler<ListViewItemEventArgs>(LstItems_ItemUpdating);
LstItems.ItemCanceling += new EventHandler<ListViewItemEventArgs>(LstItems_ItemCanceling);

Button "Edit" click.

protected void LstItems_ItemEditing(object sender, ListViewItemEventArgs e)
{
    var item = LstItems.Items[e.NewEditIndex];

    // Save the currently selected item to OldDnsRecord

    // ReBind the ListView
}

Button "Save" click.

protected void LstItems_ItemUpdating(object sender, ListViewItemEventArgs e)
{
    if (!Page.IsValid)
    return;

    var txtNewHost = e.Item.FindControl<TextBox>("TxtNewHost");
    var txtNewPointsTo = e.Item.FindControl<TextBox>("TxtNewPointsTo");
    var ddlNewTtl = e.Item.FindControl<DropDownList>("DdlNewTTL");

    var host = txtNewHost.Text;
    var pointsTo = txtNewPointsTo.Text;
    var ttl = ddlNewTtl.SelectedValue;

    var result = UpdateExistingRecord();
    if (result == Status.Ok)
    {
        LstItems.EditIndex = -1;

        // Rebind the ListView
    }
    else
    {
        // Do error handling
    }
}

Button "Cancel" click.

protected void LstItems_ItemCanceling(object sender, ListViewItemEventArgs e)
{
        LstItems.EditIndex = -1;

        // Rebind the ListView
}

ASP.NET Events

• HttpApplication.BeginRequest
• HttpApplication.AuthenticateRequest
• HttpApplication.PostAuthenticateRequest
• HttpApplication.AuthorizeRequest
• HttpApplication.PostAuthorizeRequest
• HttpApplication.ResolveRequestCache
• HttpApplication.PostResolveRequestCache
• HttpApplication.MapRequestHandler
• HttpApplication.PostMapRequestHandler
• HttpApplication.AcquireRequestState
• HttpApplication.PostAcquireRequestState
• HttpApplication.PreRequestHandlerExecute
• Page.FrameworkInitialize
• Page.InitializeCulture
• Page.OnPreInit
• MasterPage.FrameworkInitialize
• MasterPageControl.FrameworkInitialize
• PageControl.FrameworkInitialize
• MasterPageControl.OnInit
• PageControl.OnInit
• MasterPage.OnInit
• Page.OnInit
• Page.OnInitComplete
• Page.LoadPageStateFromPersistenceMedium
  If IsPostBack
• Page.LoadControlState
  If IsPostBack
• MasterPageControl.LoadControlState
  If IsPostBack, RegisterRequiresControlState was called and control state contains elements
• PageControl.LoadControlState
  If IsPostBack, RegisterRequiresControlState was called and control state contains elements
• MasterPageControl.LoadViewState
  If IsPostBack and ViewState contains elements
• PageControl.LoadViewState
  If IsPostBack and ViewState contains elements
• Page.OnPreLoad
• Page.OnLoad
• MasterPage.OnLoad
• MasterPageControl.OnLoad
• PageControl.OnLoad
• {PageControl|MasterPageControl}.OnCustomEvent
  If a custom event was fired on a control declared on the page/master page
• {PageControl|MasterPageControl}.OnBubbleEvent
  If a custom event was fired on a control declared on the page/master page
• {Page|MasterPage}.OnBubbleEvent
  If a custom event was fired on a control declared on the page/master page
• Page.OnBubbleEvent
  If a custom event was fired
• Page.OnLoadComplete
• ClientCallbackControl.RaiseCallbackEvent
  If in a client callback asynchronous request
• ClientCallbackControl.GetCallbackResult
  If in a client callback asynchronous request
• Page.OnPreRender
  If not in an asynchronous postback
• MasterPage.OnPreRender
  If not in an asynchronous postback
• MasterPageControl.OnPreRender
  If Visible
• PageControl.OnPreRender
  If Visible and not in an asynchronous postback
• Page.OnPreRenderComplete
  If not in an asynchronous postback
• Page.SaveControlState
  If not in an asynchronous postback and RegisterRequiresControlState is called for the page and control state contains additiona values
• MasterPageControl.SaveControlState
  If not in an asynchronous postback and RegisterRequiresControlState is called for the master page control and control state contains additiona values
• PageControl.SaveControlState
  If not in an asynchronous postback and RegisterRequiresControlState is called for the page control and control state contains additiona values
• Page.SaveViewState
  If not in an asynchronous postback
• MasterPage.SaveViewState
  If not in an asynchronous postback
• MasterPageControl.SaveViewState
  If not in an asynchronous postback
• PageControl.SaveViewState
  If not in an asynchronous postback
• Page.SavePageStateToPersistenceMedium
  If not in an asynchronous postback
• Page.OnSaveStateComplete
  If not in an asynchronous postback
• Page.Render
  If not in an asynchronous postback
• MasterPage.Render
  If not in an asynchronous postback
• MasterPageControl.Render
  If Visible and not in an asynchronous postback
• PageControl.Render
  If Visible and not in an asynchronous postback
• Page.OnCommitTransaction
  If Transaction = Required or RequiresNew and a transaction was committed or no transaction was created
• Page.OnAbortTransaction
  If Transaction = Required or RequiresNew and a transaction was rolled back
• MasterPageControl.OnUnload
• MasterPageControl.Dispose
• PageControl.OnUnload
• PageControl.Dispose
• MasterPage.OnUnload
• MasterPage.Dispose
• Page.OnUnload
• Page.Dispose
• HttpApplication.PostRequestHandlerExecute
• HttpApplication.ReleaseRequestState
• HttpApplication.PostReleaseRequestState
• HttpApplication.UpdateRequestCache
• HttpApplication.PostUpdateRequestCache
• HttpApplication.LogRequest
• HttpApplication.PostLogRequest
• HttpApplication.EndRequest
• HttpApplication.PreSendRequestHeaders
• HttpApplication.PreSendRequestContent

ASP.NET Page life cycle

1. Page.OnPreInit
2. MasterPageControl.OnInit (for each control on the master page)
3. Control.OnInit (for each contol on the page)
4. MasterPage.OnInit
5. Page.OnInit
6. Page.OnInitComplete
7. Page.LoadPageStateFromPersistenceMedium
8. Page.LoadViewState
9. MasterPage.LoadViewState
10. Page.OnPreLoad
11. Page.OnLoad
12. MasterPage.OnLoad
13. MasterPageControl.OnLoad (for each control on the master page)
14. Control.OnLoad (for each control on the page)
15. OnXXX (control event)
16. MasterPage.OnBubbleEvent
17. Page.OnBubbleEvent
18. Page.OnLoadComplete
19. Page.OnPreRender
20. MasterPage.OnPreRender
21. MasterPageControl.OnPreRender (for each control on the master page)
22. Control.OnPreRender (for each control on the page)
23. Page.OnPreRenderComplete
24. MasterPageControl.SaveControlState (for each control on the master page)
25. Control.SaveControlState (for each control on the page)
26. Page.SaveViewState
27. MasterPage.SaveViewState
28. Page.SavePageStateToPersistenceMedium
29. Page.OnSaveStateComplete
30. MasterPageControl.OnUnload (for each control on the master page)
31. Control.OnUnload (for each control on the page)
32. MasterPage.OnUnload
33. Page.OnUnload