I'm trying to use some AJAX and ASP.Net together to enable me to run functions without having to refresh the whole page but i've stumbled across a problem in doing this
Here's my code
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:DropDownList ID="ddl1" runat="server" OnSelectedIndexChanged="update1" />
<asp:TextBox runat="server" ID="txt1" />
</ContentTemplate>
</asp:UpdatePanel>
And here's my code behind
Sub update1(ByVal sender As Object, ByVal e As EventArgs)
txt1.Text = Now.ToString
End Sub
The event doesn't fire because I don't have AutoPostBack="True" on my ddl but adding that to the ddl will postback the whole page.
Is there a way to avoid using AutoPostBack="True" so that it only updates the panel?
I know I can use an asp:Button to get around this but i'd really like to be able to use a ddl with OnSelectedIndexChanged
Thanks
If you want to avoid to send the whole viewstate to the server, you should look at callbacks.
Instead, if you want to avoid a refresh of the entire page, but with postback, this should work:
<asp:DropDownList ID="ddl1" runat="server" OnSelectedIndexChanged="update1" AutoPostBack="True" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:AsyncPostbackTrigger ControlID="ddl1" EventName="SelectedIndexChanged" />
</Triggers>
<ContentTemplate>
<asp:TextBox runat="server" ID="txt1" />
</ContentTemplate>
</asp:UpdatePanel>
Try creating a new page with same codes and different page name. Worked for me
Related
I have a fileupload control on my .aspx page.
<asp:FileUpload ID="FileUpload1" runat="server" />
I am validating my control on my CS page.
if (FileUpload1.HasFile)
but this if condition is returning always false. I am not getting what is the actual reason! Can anyone help me in this?
FileUpload control is not compatible with UpdatePanel. You have two options
Move the control outside of UpdatePanel
If not possible, add a PostBackTrigger on the UpdatePanel
An example
<Triggers>
<asp:PostBackTrigger ControlID="yourButtonIdThatSubmitsFile" />
</Triggers>
For more information, you can refer to http://forums.asp.net/t/1142794.aspx
I have put my FileUpload Control into a Updatepanel. Then apply a trigger on those buttons from where data is submitting.
<td>
<asp:UpdatePanel runat="server" ID="updatepanel1">
<Triggers><asp:PostBackTrigger ControlID="btnsubNxtClm" /></Triggers>
<Triggers><asp:PostBackTrigger ControlID="btnsubmit" /></Triggers>
<ContentTemplate>
<asp:FileUpload ID="FileUpload1" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
</td>
I have a GridView that is bound to a SQL Data source. I have put this inside an Update panel and want the contents to update at a specified interval. The problem is that if i change the data in the database, the GridView does not update itself, i have to manually refresh the page to view the new data.
What else do I need to do to get a GridView to refresh itself?
<asp:Timer ID="RefreshTimer" runat="server" Interval="10000"
ontick="RefreshTimer_Tick">
</asp:Timer>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<div id="quad1"><uc1:MyWidget ID="MyWidget1" runat="server" /></div>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="RefreshTimer" EventName="Tick" />
</Triggers>
</asp:UpdatePanel>
You have to call gridView.DataBind() on tick event
Use a Timer like this:
<asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="30000">
Follow this Auto-refresh update panel sample and should have no problem. Let me know if you do.
I have two ASP.NET AJAX UpdatePanels .
there are two timers with diffrent intervals.
is it possible to update two updatepanels simultaneously together ?
like multi thread application .
each should be UpdatePanel Update in separate thread in one time.
i wrote this code but second timer does not work :
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
<h2>
Welcome to ASP.NET!
</h2>
<p>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
</p>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<asp:Timer ID="Timer1" runat="server" Interval="2000">
</asp:Timer>
<asp:Timer ID="Timer2" runat="server" Interval="2000">
</asp:Timer>
</asp:Content>
Behind Code :
Protected Sub Timer1_Tick(sender As Object, e As System.EventArgs) Handles Timer1.Tick
Label1.Text = Date.Now
End Sub
Protected Sub Timer2_Tick(sender As Object, e As System.EventArgs) Handles Timer2.Tick
Label2.Text = Date.Now
End Sub
Actually, your UpdatePanels are useless in this example, because your Timers are outside of them. As a result, every time your event gets triggered, it does a full page refresh. (This is in part why you never see the second Timer get hit -- by the time the first timer gets hit, the entire page gets refreshed, so the counter resets on the first timer)
So, you need to accomplish two things to fix your page:
Get the UpdatePanels to work properly with the Timers so that only asynchronous postbacks are occurring.
Make sure that each Timer only causes one UpdatePanel to refresh.
The first can be taken care of by either moving the Timer into the UpdatePanel, as a child, or by using the <asp:Triggers> element to basically say "The only thing that will update my UpdatePanel is this timer."
The second can be taken care of by setting the UpdateMode=Conditional attribute on each UpdatePanel.
Try this:
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
<h2>
Welcome to ASP.NET!
</h2>
<p>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
</p>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" ChildrenAsTriggers="false" UpdateMode="Conditional">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" />
</Triggers>
</asp:UpdatePanel>
<asp:UpdatePanel ID="UpdatePanel2" runat="server" ChildrenAsTriggers="false" UpdateMode="Conditional">
<ContentTemplate>
<asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer2" />
</Triggers>
</asp:UpdatePanel>
<asp:Timer ID="Timer1" runat="server" Interval="2000" ontick="Timer1_Tick">
</asp:Timer>
<asp:Timer ID="Timer2" runat="server" Interval="2000" ontick="Timer2_Tick">
</asp:Timer>
</asp:Content>
I have to run to work now, so bear with me if you have any questions ;-)
Im trying tp upload more than one image, and when each one I upload I will show it in a repeater, but in the code behind the FileUpload1.HasFile is always False , this is a piece of my code :
<asp:UpdatePanel ID="UpdatePanel1" runat="server" ChildrenAsTriggers="true" UpdateMode="Conditional" >
<ContentTemplate>
<asp:Repeater ID="rpUploadedImages" runat="server">
<ItemTemplate>
<img src='../Images/<%# DataBinder.Eval(Container.DataItem, "ImagePath")%>'/><br />
</ItemTemplate>
</asp:Repeater>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="btnupload" EventName="click" />
</Triggers>
</asp:UpdatePanel>
<asp:FileUpload ID="FileUpload1" runat="server" /><br />
<asp:Button ID="btnupload" runat="server" Text="Upload" onclick="btnupload_Click" />
The FileUpload control does not work with UpdatePanel, you will need to do a full post back to get the file on the server... Now there are a lot of tricks to make it ajaxy...
http://geekswithblogs.net/ranganh/archive/2008/04/01/file-upload-in-updatepanel-asp.net-ajax.aspx
Another tricky way is to create iframe with fileupload + submit button(or some trigger) inside your main form. iframe will postback with no effect to main page.
<asp:ScriptManager ID="ScriptManager1" runat="server"/>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="chkStaySignedIn" EventName="Checked" />
</Triggers>
<ContentTemplate>
<asp:Label ID="lblPassword" runat="server" Text="Password" AssociatedControlID="txtPassword"/>
</ContentTemplate>
</asp:UpdatePanel>
EventName="Checked"
Can anyone provide me a link to complete list of event names while using ajax.
The checkbox's event name is CheckedChanged
It isn't a definitive list by any means, but this MSDN page lists the default event names for common controls that post back.