Develop Reference

Event in Update panel is not fired after rebinding control after Postback

I have a Gridview together with some LinkButton inside of an Update Panel. The click events are fired correctly, the way I expect them to work. BUT: After adding an additional Header Row to the grid in code behind, I need to rebind the Grid after each postback. Since then the click causes a postback, but the method is not executed.
<asp:UpdatePanel runat="server" ID="UpdatePanel2" UpdateMode="Always">
<ContentTemplate>
<asp:GridView ID="GridViewFollowUpMove" runat="server" AutoGenerateColumns ="false" OnRowDataBound="FollowUp_RowDataBound" OnDataBound="FollowUpMove_OnDataBound">
<Columns>
<asp:TemplateField HeaderText="Due date" ItemStyle-HorizontalAlign="left">
<ItemTemplate>
<asp:LinkButton ID="LB_DueDate" runat="server" OnClick="ActivateDueDate" CssClass="NoDeco" CommandArgument='<%# Bind("ISSUEID") %>'>
<asp:Label ID="LabelDueDate" runat="server" Text='<%# Bind("DueDate","{0:dd.MM.yyyy}") %>' Width="60px" Class="line"/></asp:LinkButton>
<asp:TextBox ID="TXTBX_DueDate" runat="server" Text='<%# Bind("DueDate") %>' Font-Size="11px" visible="false" OnTextChanged="TextChanged_DueDate" AutoPostBack="true"/>
</ItemTemplate>
</asp:TemplateField>
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
FillFollowUp();
}
FillFollowUp();
}

I solved this problem by moving the commands that create and customize the additional Header row to the OnRowCreated Event. As I read somewhere: When a postback occurs, the Gridview must be recreated on the server, and in this process ItemCreated is fired for each item, but ItemDataBound is not (since the control properties are pulled from ViewState).
So building these headers in DataBound is the wrong choice!

HtmlInputCheckbox onselect event not getting invoked

I have a web application which has a gridview with first column as checkbox.
<asp:TemplateField HeaderText="Select" >
<HeaderTemplate >
<asp:CheckBox ID="chkboxSelectAll" runat="server" AutoPostBack="true" />
</HeaderTemplate>
<ItemTemplate>
<input id="chkSelect" name="chkboxSelect" runat="server" type="checkbox" onclick='CheckedChanged'/>
</ItemTemplate>
</asp:TemplateField>
And also there is a onselect event for input(checkbox) written in code behind where I will highlight the row based on whether the checkbox is checked or not.
My problem is when I check the input checkbox, the onselect event is not getting invoked. Can anyone know whats causing this issue?
Thanks in advance.

Use asp:checkbox with autopostback=true instead of HTML control

use this code.
replace html input to asp:checkbox on itemtemplate and assign new event OnCheckedChanged instead of onclick event
<asp:TemplateField HeaderText="Select" >
<HeaderTemplate >
<asp:CheckBox ID="chkboxSelectAll" runat="server" AutoPostBack="true" />
</HeaderTemplate>
<ItemTemplate>
<asp:CheckBox ID="chkSelect" runat="server" AutoPostBack="true" OnCheckedChanged='CheckedChanged'/>
</ItemTemplate>

ASP.NET Ajax Accordion header event

in ASP.NET 4 Website
I need to fire a server side C# function when an ajax accordion header is clicked, passing the header data value to the function. The accordion is filled from a database. How do I create the event to call the C# function?
<ajaxToolkit:Accordion ID="acc1" runat="server" Width="300px"
HeaderCssClass="accHeader" ContentCssClass="accContent" CssClass="accMain"
FadeTransitions="true" SuppressHeaderPostbacks="false" TransitionDuration="250" RequireOpenedPane="false"
HeaderSelectedCssClass="accSelHeader" FramesPerSecond="40">
<HeaderTemplate><b><%#DataBinder.Eval(Container.DataItem, "CompanyName") %></b></HeaderTemplate>
<ContentTemplate>
<%#DataBinder.Eval(Container.DataItem, "CompanyName") %><br />
<%#DataBinder.Eval(Container.DataItem, "Street")%><br />
<%#DataBinder.Eval(Container.DataItem, "City")%><br />
<%#DataBinder.Eval(Container.DataItem, "StateOfFacility")%><br />
<%#DataBinder.Eval(Container.DataItem, "ZipCode")%><br />
<%#DataBinder.Eval(Container.DataItem, "Phone")%><br />
<%#DataBinder.Eval(Container.DataItem, "URL")%><br />
</ContentTemplate>
</ajaxToolkit:Accordion>

Use LinkButton in header and handle ItemCommand event of Accordion as below:
<HeaderTemplate>
<asp:LinkButton runat="server" Text='<%# Eval("CompanyName") %>'
CommandName="Select" CommandArgument='<%# (int)Eval("Id") %>' />
</HeaderTemplate>
void acc1_ItemCommand(object sender, CommandEventArgs e)
{
if (e.CommandName == "Select")
{
var companyId = e.CommandArgument;
}
}
Draw your attention that you need to provide companies unique identifier to distinguish clicked company pane.

Using GridView inside UpdatePanel

I have an Updatepanel and Gridview inside it.
<asp:UpdatePanel ID="uplPanel" UpdateMode="Conditional" runat="server" OnLoad="uplPanel_Load">
<ContentTemplate>
<asp:GridView ID="gvPrList" runat="server" AutoGenerateColumns="false" AllowPaging="false"
AllowSorting="false" CssClass="list-table" HeaderStyle-CssClass="header">
<Columns>
<ItemTemplate>
<asp:Button ID="btnEdit" runat="server" Text="Edit" CssClass="button save" OnCommand="onPrItemCmd"
CommandName="editRow" CommandArgument='<%#Bind("ID") %>' Style="width: 80px" />
<asp:Button ID="btnDelete" runat="server" Text="Delete" CssClass="button save" OnCommand="onPrItemCmd"
CommandName="deleteRow" CommandArgument='<%#Bind("ID") %>' Style="width: 80px" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
When I click on my buttons inside the Griview, it does not fire the events.
Any idea?

You need to add OnCommand event of GridView and then handle that inside that event like this:
OnRowCommand="gvPrList_OnRowCommand"
or alternatively add a click event for the individual button and then handle in the code behind file:
<asp:Button ID="btnEdit" runat="server" OnClick="btnEdit_Click" Text="Edit" CssClass="button save"
OnCommand="onPrItemCmd" CommandName="editRow" CommandArgument='<%#Bind("ID") %>' Style="width: 80px" />

I had the same issue where column buttons with a OnClick were causing a postback but the OnClick method was not being hit. When I commented out the update panel and it all worked.
I resolved this issue by adding a postback trigger for the grid within the update panel:
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="uxWebDataGrid" />
</Triggers>
</asp:UpdatePanel>
Hope this helps someone else!

I did the following and it works
I replace asp button with html button and call javascript method to fire Update Panal Load event.
<input id="btnDelete1" type="button" onclick="javascript:DeletePrItem('<%# Eval("ID") %>');" value="Delete" class="button save" style="width: 80px" />
My Js :
function DeletePrItem(_Id) {
__doPostBack('<%= uplPanel.ClientID %>', _Id);
}
My Code behind :
protected void uplPanel_Load(object sender, EventArgs e)
{
var arg = Request.Params.Get("__EVENTARGUMENT");
if (arg != null)
{
if (arg != "")
{
string recordId = arg.ToString();
//Do deletetion and rebind data grid
}
}
}

This would be the Event Handler for your command in the codebehind:
protected void onPrItemCmd(object sender, CommandEventArgs e)
{
//do whatever you want
//probably you will need the "ID" or "CommandArgument":
string myArgumentID = e.CommandArgument.ToString();
uplPanel.Update(); //since the UpdatePanel is set *UpdateMode="Conditional"*
}
UPDATE:
Probably, you might be doing some validation when you click on buttons. If so, you need to add CausesValidation="false" in your buttons or links properties

I had a similar issue.
Depending on your situation, as in mine...All of the clickable controls inside of the update panel I will want to be triggers; So i was simply able to use the UpdatePanel property 'ChildrenAsTriggers="true"' so solve the issue.
<asp:UpdatePanel runat="server" ID="UPCommunicationlogForm" ChildrenAsTriggers="true" >
This solved my issue, now my edit and delete buttons that are generated from the ItemTemplate inside my gridview call their respective methods on the server.

Please add this code into the UpdatePanel.
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="gvPrList" EventName="Click" />
</Triggers>
</asp:UpdatePanel>

I added an OnRowCommand Event and add this trigger to the UpdatePanel:
<Triggers>
<asp:AsyncPostBackTrigger ControlID="gvPrList" EventName="RowCommand" />
</Triggers>
Note that it's an Async trigger.

This helped me.
In my case I was changing a value in a asp:DropDownList control and then going back to the server to update my asp:GridView which is in a different asp:UpdatePanel. I just forgot to add code to refresh the Update Panel with the list. Once I did that everything worked fine.
Server side
System.Data.DataSet ds = MySQL.DAL.GetRecord(sql);
GV_View.DataSource = ds;
GV_View.DataBind();
UP_MainList.Update(); //refresh the update panel
Aspx code
<asp:UpdatePanel runat="server" ID="UP_ListChange" UpdateMode="Conditional">
<ContentTemplate>
<asp:DropDownList runat="server" ID="ddFilter" DataTextField="Desc" AutoPostBack="true" DataValueField="Detail" OnSelectedIndexChanged="GV_CodeView_RefreshScreen" ></asp:DropDownList>
</ContentTemplate>
</asp:UpdatePanel>
<div class="medium">Select Filter to view database codes</div>
</div>
<div class="div-row-header" runat="server" id="divList">
<asp:UpdatePanel runat="server" ID="UP_MainList" UpdateMode="Conditional">
<ContentTemplate>
<asp:GridView ID="GV_View" runat="server" AllowSorting="True" AutoGenerateColumns="false" DataKeyNames="id">
<Columns>
<asp:BoundField DataField="Id" HeaderText="Id" Visible="false" />
<asp:BoundField DataField="Type_Cd" HeaderText="Code" />
<asp:BoundField DataField="Short_Desc" HeaderText=" Description" />
<asp:TemplateField HeaderText="">
<ItemTemplate>
<asp:Button ID="Code_Edit" runat="server" Text="Edit" onClick="GV_Code_Edit_Click" class="button" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</ContentTemplate>
</asp:UpdatePanel>
</div>

Getting Failed to load viewstate error

First off, I am not dynamically creating any controls. This is the order I take to produce the error:
I have a listview on the page, when I click the edit link under the listview, I display a panel which is hidden by default. The panel has a few buttons on it along with some listboxes. When I click an item in the listbox or click one of the buttons, I get the following error:
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
Again, I am not creating anything dynamically, I am just hiding the panel with the controls by default and then displaying them, so I am not sure why I am getting this error.
Here is some code:
PAGE LOAD
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
Session["Albums"] = null;
Albums = AlbumCollection.GetAlbums(Common.GetUserName(),
ddlAlbumType.SelectedIndex);
lvwAlbums.DataSource = Albums;
lvwAlbums.DataBind();
}
}
When I click the edit link, this is the code that runs:
protected void lvwAlbums_RowEditing(object sender, ListViewEditEventArgs e)
{
this.AlbumId = int.Parse(
this.lvwAlbums.DataKeys[e.NewEditIndex].Values["AlbumId"].ToString());
this.AlbumName=
this.lvwAlbums.DataKeys[e.NewEditIndex].Values["AlbumName"].ToString();
Album album = new Album(this.AlbumId);
ViewState["AlbumId"] = this.AlbumId;
ViewState["AlbumName"] = this.AlbumName;
pnlAlbum.Visible = true; // This panel holds the controls
btnEditAlbum.Visible = true;
btnCancel.Visible = true;
EditAlbum(this.AlbumId);
this.lvwAlbums.EditIndex = e.NewEditIndex;
AlbumCollection.GetAlbums(Common.GetUserName(),ddlAlbumType.SelectedIndex);
}
If I click the cancel button, I get the error, but it also happens if click another button on the panel such as Add/Remove... Here is the code for the Cancel button:
pnlAlbum.Visible = false;
this.lvwAlbums.EditIndex = -1;
AlbumCollection.GetAlbums(Common.GetUserName(), ddlAlbumType.SelectedIndex);
Here is the aspx/html for the ListView:
<asp:ListView ID="lvwAlbums"
runat="server"
GroupItemCount="5"
DataKeyNames="AlbumId,AlbumName"
OnItemEditing="lvwAlbums_RowEditing"
OnItemCommand="lvwAlbums_ItemCommand"
OnItemDeleting="lvwAlbums_RowDeleting"
OnSelectedIndexChanging="lvwAlbums_SelectedIndexChanging"
OnPagePropertiesChanging="lvwAlbums_PagePropertiesChanging">
<EditItemTemplate>
<td>
<div>
<asp:TextBox ID="txtAlbumName" runat="server"
Text='<%# Eval("AlbumName").ToString().Trim() %>' />
<asp:LinkButton ID="lnkView" runat="server" Text="View" CommandName="View"
CommandArgument='<%# Eval("AlbumId") %>'>
</asp:LinkButton>
|
<asp:LinkButton ID="lnkEdit" runat="server" Text="Edit" CommandName="Edit"
CommandArgument='<%# Eval("AlbumId") %>'>
</asp:LinkButton>
|
<asp:LinkButton ID="lnkDelete" runat="server" Text="Delete" CommandName="Delete"
CommandArgument='<%# Eval("AlbumId") %>'>
</asp:LinkButton>
<br />
<span>Songs:
<%# Eval("total") %></span>
</div>
</td>
</EditItemTemplate>
<LayoutTemplate>
<asp:DataPager runat="server" ID="ItemDataPager" PageSize="20"
PagedControlID="lvwAlbums">
<Fields>
<asp:NumericPagerField ButtonType="Link" NumericButtonCssClass="pager" />
</Fields>
</asp:DataPager>
<table>
<tr>
<td>
<table>
<asp:PlaceHolder runat="server" ID="groupPlaceHolder"></asp:PlaceHolder>
</table>
</td>
</tr>
</table>
</LayoutTemplate>
<GroupTemplate>
<tr>
<asp:PlaceHolder runat="server" ID="itemPlaceHolder"></asp:PlaceHolder>
</tr>
</GroupTemplate>
<ItemTemplate>
<td>
<asp:Literal ID="litAlbumName" runat="server"
Text='<%# Eval("AlbumName").ToString().Trim() %>' />
<br />
<asp:LinkButton ID="lnkView" runat="server" Text="View" CommandName="View"
CommandArgument='<%# Eval("AlbumId") %>'>
</asp:LinkButton>
|
<asp:LinkButton ID="lnkEdit" runat="server" Text="Edit" CommandName="Edit"
CommandArgument='<%# Eval("AlbumId") %>'>
</asp:LinkButton>
|
<asp:LinkButton ID="lnkDelete" runat="server" Text="Delete" CommandName="Delete"
CommandArgument='<%# Eval("AlbumId") %>'>
</asp:LinkButton>
<br />
<span>Songs:
<%# Eval("total") %></span>
</td>
</ItemTemplate>
</asp:ListView>
Here is the markup for the Panel:
<asp:Panel ID="pnlAlbum" runat="server" Visible="false">
<asp:ListBox ID="lstAvailableSongs" runat="server" SelectionMode="Multiple">
</asp:ListBox>
<asp:Button ID="btnAddAll" runat="server" Text="Add All" OnClick="btnAddAll_Click" />
<asp:Button ID="btnAdd" runat="server" Text="Add" OnClick="btnAdd_Click" />
<asp:Button ID="btnRemove" runat="server" Text="Remove" OnClick="btnRemove_Click" />
<asp:Button ID="btnRemoveAll" runat="server"
Text="Remove All"OnClick="btnRemoveAll_Click" />
<asp:ListBox ID="lstSelectedSongs" runat="server" SelectionMode="Multiple">
</asp:ListBox>
<asp:Button ID="btnCancel" runat="server" Text="Cancel" OnClick="btnCancel_Click" />
<asp:Button ID="btnEditAlbum" runat="server"Text="Save"
ValidationGroup="CreateAlbum" OnClick="btnEditAlbum_Click" />
<asp:Button ID="btnSaveAs" runat="server" Text="Save As" ValidationGroup="CreateAlbum"
OnClick="btnSaveAs_Click" />
</asp:Panel>
Here is some extra info:
I put an update panel around one of the listboxes in the panel and when I clicked the edit link under a listview item, I received the following error:
Microsoft JScript runtime error: Sys.InvalidOperationException: Could not find UpdatePanel with ID 'ctl00_ctl00_InnerContent_MainContent_UpdatePanel4'. If it is being updated dynamically then it must be inside another UpdatePanel.
Putting an UpdatePanel around the whole asp.net panel resolved the issue above, but I still get the Failed to load viewstate error when clicking on Cancel or Add, etc...

First off, you probably need to rebind the ListView after setting the EditIndex. (honestly, I haven't used ListView at all, but this is how the other repeater controls work) What does "EditAlbum()" do?
Your code is a little odd... why do you have the same controls in your EditItemTemplate as in the ItemTemplate? Ie, the Edit button should only be in the ItemTemplate... Then EditItemTemplate should have a Save or Cancel button.
Bottom line... your control tree is different on LoadViewState than it is when SaveViewState was called. One thing you can do is override these methods and then put a breakpoint there to manually look at the Controls collection in the debugger. You will probably see that the controls inside the ListView are different. But try my first suggestion before you do this.

Question for you:
in your Page_Load you have
Albums = AlbumCollection.GetAlbums(Common.GetUserName(), ddlAlbumType.SelectedIndex);
but in lvwAlbums_RowEditing(..) and in btnCancel_Click(...) you have
AlbumCollection.GetAlbums(Common.GetUserName(), ddlAlbumType.SelectedIndex);
shouldn't these be (Albums = ...)
Albums = AlbumCollection.GetAlbums(Common.GetUserName(), ddlAlbumType.SelectedIndex);