I have the following ASPX code:
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel runat="server" ID="UpdatePanel" UpdateMode="Conditional">
<ContentTemplate>
<asp:Button runat="server" ID="UpdateButton1" OnClick="NextImg_Click" Text="Update" />
<asp:Repeater runat="server" ID="urlsUpdateRepeater">
<ItemTemplate>
<!-- THIS WOULD BE A LOOP FROM HERE -->
<!-- OPENS RESULT ITEM DIV CONTAINER -->
<div id="result_item">
<a href="<%# Eval("myUrl") %>" target="_blank">
<%# Eval("urlPageTitle")%></a>
</ItemTemplate>
</asp:Repeater>
</ContentTemplate>
</asp:UpdatePanel>
I have a NextImg_Click() event which works fine.
I use this code for DataBind... what is the Update method?
urlsUpdateRepeater.DataSource = resultsCollection;
urlsUpdateRepeater.DataBind();
Everything would appear to be in order. But every time the Update button is clicked it re-renders the whole page instead of the partial-postback UpdatePanel only.
It is driving me completely mad as I can't see anything wrong with the code. Is there some simple thing I'm missing?! Please help!
The search and data is displayed correctly (inside the panel) it just will not do a partial postback.
Appreciate your help with my noob problems!
Because the button is inside your UpdatePanel's ContentTemplate, it is unnecessary to take any extra action to get a partial page postback.
Try removing the line from your Page_Load() method.
Taken from MSDN:
Use the RegisterAsyncPostBackControl
method to register controls outside an
UpdatePanel control as triggers for
asynchronous postbacks, and to
potentially update the content of an
update panel. To update an UpdatePanel
control programmatically, call the
Update method.
So, you're control (UpdateButton1) is inside the UpdatePanel, no need for the ScriptManager1.RegisterAsyncPostBackControl call - ditch it and your problem is solved.
The problem was that my <form> tag was nested further into the document than it's corresponding end tag (with Warning!)...
Upon moving my form tag - it worked!
Entirely my fault, thanks guys.
Related
Everything works as it should. I just find it annyoing that if you manage to click the checkbox "during" the update of the updatepanel it does not grab the click. Is there som workaround/fix for this or do I simply have to rethink my design and put the checkboxes in a different panel?
If you use AutoPostBack="True", checkbox will be working fine. Thanks
<asp:UpdatePanel ID="updatepanel" runat="server">
<ContentTemplate>
<asp:Checkbox ID="chk" runat="server" AutoPostBack="true"></asp:CheckBox>
</ContentTemplate>
</asp:UpdatePanel>
Your logic update shouldn't be on the same thread/task of the View (except some cases). Look for "c# async", you will find everything you need in Internet.
I have the following situation:
A master page with a usercontrol inside an update panel that triggers each minute by a timer.
In a content page i have an ajaxToolkit:AjaxFileUpload which have the functionality drag and drop, at page load the upload control is working fine but after the first trigger on the update panel the control stops working.
Thanks in advance.
I was able to replicate the issue and solve it by placing the AjaxFileUpload control inside of the ContentTemplate node of an UpdatePanel.
If you place it in its own UpdatePanel, make sure the UpdateMode is set to "Always". If you want it to be "Conditional", you'll need to have it be updated with the trigger in some way.
<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Always">
<ContentTemplate>
<ajaxToolkit:AjaxFileUpload ID="AjaxFileUpload2" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
It is very bad situation,sometimes in some pages of my web application i get this error:
A control with ID 'BtnSubmit' could not be found for the trigger in UpdatePanel 'UpdatePanel3'.
but if i build again and load that page it loads corectlly,but after that if i reload the page get error again,
why it is this way?How could i fix it,or find what is the detail of my problem?
in my updatepanel i dont have trigger BtnSubmit and i know the default value of 'ChildrenAsTriggers' properties if updatepanel is true,so please help me
May be you are doing this:
<asp:UpdatePanel ID="UpdatePanel3" runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="BtnSubmit" /> //since BtnSubmit not declared any where or BtnSubmit is not accessible for UpdatePanel3
</Triggers>
<ContentTemplate>
<%-- Content--%>
</ContentTemplate>
</asp:UpdatePanel>
try adding Button(BtnSubmit) where UpdatePanel3 can access. you can add within updatepanel or outside.
<asp:Button ID="BtnSubmit" runat="server" Text="Button" />
tank you #ashwini but i found that my master page .cs file was damaged, i deleted masterpage and created it again, and now every thing is ok. it take my time because i didn't get any thing of the error message! thank to any way.
How can I prevent a page from going back to the top every time a button is click? I still want to execute the code on the "OnClick" event for the button.
Example:
Almost all of our forms have a button on the bottom of the page which are suppose to bring some data back from the DB and populate some labes and textboxes located on the bottom of the page, when the button is click it takes user back to the top of the page. How can I prevent this from happening?
Any help will be really appreciate it.
Assuming the OnClick event is handled on the server and not in javascript, the easiest thing is wrap the controls to be updated in an UpdatePanel and have the update panel trigger on the button's click event.
Here is an example from Microsoft's documentation:
<asp:Button ID="Button1"
Text="Refresh Panel"
runat="server" />
<asp:ScriptManager ID="ScriptManager1"
runat="server" />
<asp:UpdatePanel ID="UpdatePanel1"
UpdateMode="Conditional"
runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Button1" />
</Triggers>
<ContentTemplate>
<fieldset>
<legend>UpdatePanel content</legend>
<%=DateTime.Now.ToString() %>
</fieldset>
</ContentTemplate>
</asp:UpdatePanel>
There are two options:
Use ASP.NET Ajax, in particular the UpdatePanel control
Set MaintainScrollPositionOnPostback to true on page level or in web.config
in your page declaration you can add MaintainScrollPositionOnPostback="true" ie:
<%# Page Language="C#" ... MaintainScrollPositionOnPostback="true" %>
you can also put that in your web.config under system.web or declare it from codebehind Page.MaintainScrollPositionOnPostback=true;
In the function handler for the button make sure you return false. You might be actually posting the page with those buttons rather than just doing something on the click event.
I have a page with an UpdatePanel that contains a Repeater and a text box with the number of items in the repeater. When I change the value, the page is supposed to post back and redraw the Repeater with the updated number of items. This works in principle, but the page ends up frozen after post-backs and does not accept any input - in IE 8 only. It works perfectly fine in Firefox. For instance, the context menu does not appear when I right-click in controls, and I cannot enter text in text boxes.
When I take out the UpdatePanel, the page works fine, but of course refreshes on every post-back event. This is not necessarily related to the Repeater on the page. I think I am seeing this on other pages. What's the trick here?
<asp:UpdatePanel ID="uPanel" runat="server" UpdateMode="Conditional"
EnableViewState="true" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:Panel ID="Panel1" runat="server" DefaultButton="btnSubmit">
<asp:TextBox ID="tbItems" runat="server" AutoPostback="true"
OnTextChanged="textchanged_Items"/>
<asp:Repeater id="rptItems" runat="server"
OnItemDataBound="repeaterItem_Databound">
<...>
</asp:Repeater>
protected void textchanged_Items(object sender, EventArgs e) {
try {
// this methods rebinds the repeater to a List after changing
// the number of items in the list
ReflowItemRepeater();
// This is not really necessary, since Databind() appears to
// cause an update. I tried it anyways.
uPanel.Update();
}
catch (Exception ex) {
ShowError(this, "Error displaying the item list.", ex, true);
}
}
I ended up removing the update panel.
One month later, different page, I am still and again fighting this. The situation is the same.
An update panel, a repeater (actually 2 nested repeaters), and a control in the repeater that fires a postback event. The server processes the event correctly and returns control, but the browser (IE8) never refreshes the update panel. The page is unresponsive, as if in some sort of dead-lock situation. I can unlock it by clicking on a button that fires another postback event (also in the update panel). But the text boxes in the panel are not clickable or editable when this happens.
Also, it happens only the first time. Once I have "freed up" the lock, or whatever it is, it will not happen again on this page, even when I repeat the exact same steps that led to it.
When this happens, the JIT debugger does not report anything.
I would actually set Triggers within your updatepanel.
I'm not sure you need to call .Update in your code behind as the updatepanel will be updated when the trigger occurs.
Try this:
My gut feeling is that it has something to do with the use of the OnTextChanged event. For kicks, try adding a button next to the text box, and reflow the repeater when the button is clicked instead. Does IE still freeze?
So I stripped this page down to the minimum and I found out what is doing it - the AjaxToolkit:CalendarExtender. If I take it out, everything works fine. Still, I would be curious to know if there is a workaround.
Here is a link to my test page. I will keep it up for a few days.
To see the issue, select "2" from the drop-down, then type something into the first quantity field and tab out. The cursor will blink in the next field, but it does not allow input. This happened in IE8, not in Firefox.
Edit: Actually, when I went back to the full page and removed the CalendarExtender, it was still not working. I do suspect that this issue has to do with controls posting back in the UpdatePanel, but I just can't pin it down. It seems seems to be one of these things where a combination of x things does not work, while any combination of (x-1) things does work.
Regarding the initial question, here's a working sample. I don't know if it's anyhow helpful, but just to make sure...
<%# Page Language="C#" %>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server"><title>Ajax Test</title></head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager runat="server" />
<asp:UpdatePanel runat="server" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:Label runat="server" AssociatedControlID="txtTest">
Enter 'fruit' or 'vegetables':
</asp:Label>
<asp:TextBox
runat="server" ID="txtTest" AutoPostBack="true"
OnTextChanged="Handler_Test_TextChanged"
/>
<asp:Repeater runat="server" ID="rptItems">
<HeaderTemplate><ul></HeaderTemplate>
<ItemTemplate><li><%# Container.DataItem.ToString() %></li></ItemTemplate>
<FooterTemplate></ul></FooterTemplate>
</asp:Repeater>
</ContentTemplate>
</asp:UpdatePanel>
</form>
</body>
</html>
<script runat="server">
static readonly string[] Fruit = new string[]
{ "Apples", "Oranges", "Bananas", "Pears" };
static readonly string[] Veg = new string[]
{ "Potatoes", "Carrots", "Tomatoes", "Onion" };
void Handler_Test_TextChanged(object s, EventArgs e)
{
if(txtTest.Text == "fruit") rptItems.DataSource = Fruit;
else if(txtTest.Text == "vegetables") rptItems.DataSource = Veg;
else return;
rptItems.DataBind();
}
</script>