ASP.Net repeater Item Command not getting fired - asp.net

OK, I've used repeaters literally hundreds of times without problems but something has gone awry today. I have a repeater and I'm subscribing to the itemCommand event, but when my command runs, the page posts back but the event isn't fired.
To get around this I'm having to do my databinding on each postback.
My repeater looks like this:
<asp:Repeater id="MyRepeater" runat="server" onitemcommand="MyRepeater_ItemCommand">
<ItemTemplate>
<li>
<asp:Label id="Label" runat="server" />
<asp:LinkButton id="LinkButton1" runat="server" commandname="Complete" commandargument='<%# Eval("MyID") %>' text='<%# Eval("Title") %>' />
</li>
</ItemTemplate>
</asp:Repeater>
and my codebehind like this:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SetupPage();
}
}
private void SetupPage()
{
// Do other stuff
MyRepeater.DataSource = Repository.GetStuff()
MyRepeater.DataBind();
}
protected void MyRepeater_ItemCommand(object sender, RepeaterCommandEventArgs e)
{
// Do all my stuff here
}
MyRepeater_ItemCommand is not getting called unless I comment out the if (!IsPostBack) line. Once that is commented out and the repeater is getting databound on each postback it works OK. I've done this in so many other pages but on this on it just doesn't seem to work.
Anyone else come across this behaviour or have a solution?

Most likely, you have disabled ViewState for the page.
The reason is that when you execute the postback, all the controls in the repeater are rebuild from the data in the viewstate normally. Then the object that should receive the event is identified based on the ID of the control, and the event is routed.
If you disable the viewstate, the control tree is not rebuild during postback, and therefore the control that should receive the event does not exist in memory. So the event dies.
If you really want to disable the viewstate, but still want to receive the event, I have a workaround (and it's not dirty at all). I've long been thinking about writing a blog entry about it, so if you want, I can take a bit time off my normal chores, and describe it.
Edit: The workaround is described here: http://petesdotnet.blogspot.dk/2009/08/asp.html

Remove if (!IsPostBack) as this is preventing the repeater from rebinding,
and the item command event could not find the row after postback.

I have the same problem and aside from using update panel, I have a required field validator in my modal. I found out that the LinkButtons in my repeater triggers the requiredFieldValidor event and then I added CausesValidation="false" in the LinkButtons of my repeater. Works as expected.

I have this problem in a repeater when I use ImageButton ...
I have search the net for this solution when LinkButton work, but not ImageButton ...
Then I think, LinkButton work? so i will use it :)
<asp:LinkButton CommandName="Filter" CommandArgument='<%# Eval("ID") %>' Text="" runat="server" >
<asp:image imageurl='<%#Eval("Img") %>' runat="server"/>
</asp:LinkButton>
So, the image is inside the <A> tag
have fun :)

I removed PostBackUrl property in linkbutton and ItemCommand fired. I think postback runs first.

That may be you have set Validations on your page. So set an new attribute, causevaliation = "false" to Link button. M sure it will solve the problem

I had a similar issue - turned out some discreet validation controls were firing elsewhere on the page. It only took me a day to figure it out ...

I am not positive about this, but you might have to set the CommandName and optionally CommandArgument properties for the button causing the ItemCommand event. Otherwise ASP.NET would assume that there is no button on the page, which you'd like to fire the event. You can try that.
Plus, if you're not differentiating between command names, why not use each button's Click event instead? Just subscribe to those in the repeater's ItemCreated or ItemDataBound.

Try using Page_init instead of Page_load and that should fix the problem.

Try this:
protected void Page_Load(object sender, EventArgs e)
{
SetupPage();
}
If you use nested-repeater, you should rebind your inner repe

Here Is the code you have to use in code behind..
after PageLoad event,
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Page_LoadComplete(object sender, EventArgs e)
{
// Bind Your Repeater here
rptUser();
}
now you can fire your Itemcommand..if you get Output please mark answer as right thanks

One other thing that it could be (as it just happened to me): if your databind takes place when your page is prerendered, it won't process the item command. Switch it to load or init and you'll be fine.

Related

How to set focus back to control that originated postback

To avoid unwarranted "duplicate" flagging, let me say upfront - I have searched high and low for an answer and only found ones like this, which has no answer, or this, which tells me to use MyControl.Focus(); from my code behind. That does not work properly. I will explain.
I have a series of dropdown controls in an update panel, each of which affects the ones after it - City, Building and Room. When the user changes the selection in the city dropdown, mouse or keyboard, focus is immediately lost as the page does the partial postback. Ok, so I try to put in the CityListDropDown.Focus();, but that causes the page to reposition itself so that this control is at the bottom of the visible area of the page - not the desired behavior. The page should not move at all. Mind you, this only matters if you have a lot of other stuff on the page before your update panel, so that these prompts are lower down where the page has had to scroll down to them.
So, how do I restore focus back to that city drop down so when the user is using the keyboard, they can just keep on trucking to the next prompt? Same goes for the building drop down.
Here is my html:
<asp:UpdatePanel ID="RoomsUpdatePanel" runat="server" UpdateMode="Conditional" RenderMode="Inline">
<ContentTemplate>
<asp:DropDownList ID="CityListDropDown" runat="server" class="form-control input-sm" Width="140" AutoPostBack="True" OnSelectedIndexChanged="CityListDropDown_SelectedIndexChanged">
</asp:DropDownList>
<asp:DropDownList ID="BuildingListDropDown" runat="server" class="form-control input-sm" AutoPostBack="True" Width="100" OnSelectedIndexChanged="BuildingListDropDown_SelectedIndexChanged">
</asp:DropDownList>
<asp:DropDownList ID="RoomListDropDown" runat="server" class="form-control input-sm" AutoPostBack="False" Width="175">
</asp:DropDownList>
</ContentTemplate>
</asp:UpdatePanel>
and here is my code behind:
protected void CityListDropDown_SelectedIndexChanged(object sender, EventArgs e)
{
LoadBuildingList();
LoadRoomList();
CityListDropDown.Focus();
}
protected void BuildingListDropDown_SelectedIndexChanged(object sender, EventArgs e)
{
LoadRoomList();
BuildingListDropDown.Focus();
}
If you don't want the page to scroll / get repositioned whenever the focus is changed, you can use the PageMaintainScrollPositionOnPostback property of the Page directive :
<%# PageMaintainScrollPositionOnPostback="true" ... %>
or you can try setting it programatically through code :
Page.MaintainScrollPositionOnPostBack = true;
I got it! So using the code behind Focus() method of the control causes the page to reposition itself, even when you have set the MaintainScrollPositionOnPostBack property of the page to true. But, javascript can change focus without moving the page around unnecessarily. So if I need to reset focus from my code behind, to the sending control, I can do this:
protected void CityListDropDown_SelectedIndexChanged(object sender, EventArgs e)
{
LoadBuildingList();
LoadRoomList();
ScriptManager.RegisterStartupScript(CityListDropDown, CityListDropDown.GetType(), "CityDropDownRefocus", "document.getElementById(\"" + CityListDropDown.ClientID + "\").focus();", true);
}
or, if I want that line of code that resets the focus to be more generic (say I have an event handler that is used by multiple controls, and I need the handler to reset focus to the control that generated the postback, the handler is going to get the sending object, so I can say:
protected void MyControlHandler(object sender, EventArgs e)
{
...
ScriptManager.RegisterStartupScript((WebControl)sender, sender.GetType(), "CityDropDownRefocus", "document.getElementById(\"" + ((WebControl)sender).ClientID + "\").focus();", true);
}
And that resets the focus back to the sending control, without moving the page around!

asp gridview plus button command

I have a Gridview based on a Acces DB in .aspx
I added +1 column to the grid, which is:
<asp:TemplateField HeaderText="view">
<ItemTemplate>
<asp:LinkButton runat="server" Text="Select" CommandName="Select" CausesValidation="False" id="Button1"></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
I have a button outside of the grid: Button2
Could I add a command to Button1, to simulate to click on Button2 as well?
EDIT: Found a link here: that talks specifically about wiring multiple events to the same handler, from MSDN:
If you already have an event handler, you can bind several control
events to it. These multiple events can be from the same control or
one event from several different controls, as long as the events all
have the same method signature. For example, you might want to bind
the Click events of several Button server controls on an ASP.NET page
to a single event handler. When your handler is called, you can
determine which control caused the event.
Yes! If you are familiar with wiring up a button then all you have to do is point both of them to the same function and clicking either one will fire the same function.
If you want to do this withing visual studio just double click each button in the designer and this will give you a function on the code behind, within that function just add a call to the function you want to call.
You should create a seperate function that is called from both buttons.
Like this:
protected void Button1_Click(object sender, EventArgs e)
{
buttonCallFunc();
}
protected void Button2_Click(object sender, EventArgs e)
{
buttonCallFunc();
}
protected void buttonCallFunc()
{
//Code goes here
}

Lost listview datasource when button clicked

I have radlistview. I add datasource to listview when page_load. But when I clicked I button in same page. I lost datasource of listview. Why? how can I fix it?
Try putting your listview databinding code inside something like this.
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
myListview.DataSource = myDatasource;
myListView.DataBind();
}
}
You may also want to consider using UpdatePanels if you wanting to only postback a part of the page, rather than the whole page.
I found the solution. I added EnableViewState="true" property and problem fixed. Like this
<telerik:RadListView ID="lvDSTableSelection" runat="server" AllowMultiItemSelection="true" OnSelectedIndexChanged="lvDSTableSelection_SelectedIndexChanged" EnableViewState="true" >

ASP.NET call a function in code behind with LinkButton

I have this LinkButton here
<asp:LinkButton runat="server" ID="EditBtn" CssClass="LinkButton" Text="Edit" Width="45px" OnClientClick="Profiles_Edit" CommandName="edit" />
and I am trying to call this function in my code behind
protected void Profiles_Edit(Object sender, ListViewCommandEventArgs e)
{
//do something
}
but when I click on the button....nothing happens. My LinkButton is inside an ItemTemplate, which is inside a ListView, which is inside a ContentTemplate, which is inside a UpdatePanel....
What is wrong with the way I am calling it?
Thanks,
J
OnClientClick is for specifying the name of the JavaScript function on the client browser.
To call the server-side event, use OnClick.
Also, you may not need the CommandName attribute in this situation. It isn't clear where this LinkButton resides. If it's in a container like a ListView, you would handle it differently.

asp.net listbox problem

foreach (Book b in o.list)
{
ListBox_Items.Items.Add(b.Title);
}
After I do this, the titles are now showing up in the listbox.
When I make a selection (Single Mode), ListBox_Items (Screen) is highlighting the row selected, but event SelectedIndexChanged is not triggering.
protected void ListBox_Items_SelectedIndexChanged(object sender, EventArgs e)
{
int i = ListBox_Items.SelectedIndex;
}
ID="ListBox_Items" runat="server" EnableViewState="False" Width="400px" Rows="25" onselectedindexchanged="ListBox_Items_SelectedIndexChanged"
Any ideas ?
Michael
Edit 1 : Thanks to everyone for helping out. Got it to work now. Anyway, I had to turn on EnableViewState to True too. Because I have a "Remove" button to remove items from the listbox control, if EnableViewState is False, whenever I clicked the Remove button, the listbox becomes empty again.
Add AutoPostBack="True" in your aspx tag
Try the following code.
<asp:ListBox ID="ListBox_Items"
runat="server"
EnableViewState="False"
Width="400px"
Rows="25"
OnSelectedIndexChanged="ListBox_Items_SelectedIndexChanged"
AutoPostBack="true"></asp:ListBox>
Do you have anything to make the page post back to the server?
You may need either a submit button, or you can add the property AutoPostBack="true" to your ListBox control.
See this MSDN Article for more information.
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.listcontrol.autopostback.aspx

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