I have been trying to find a way to relay incremental feedback of a process to the UI via an update panel. A basic example of what I am trying to implement is as follows:
protected void DoSomething(object sender, EventArgs e) {
for(int i=0; i < 10; i++){
//Pretend to do something intensive
Thread.Sleep(1000);
//Output the progress of the process to a label
Label.Text = i.ToString();
}
}
The aspx markup in my example is simply:
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Button1" />
</Triggers>
<asp:Button ID="Button1" runat="server" OnClick="DoSomething" Text="Push Me"/>
However when Button1 is pressed the UpdatePanel does not update incrementally, instead it only displays the number 9 when the loop completes.
I believe this is because no postback is triggered until the server side code completes (i.e. when the loop stops looping).
Is there a way I can achieve the desired functionality using server side code and update panels?
Thanks in advance! :)
What you can do is, create a timer object in design mode (or punch it in your html code) and also add a async trigger to that timer. This link will help you a great deal!
http://msdn.microsoft.com/en-us/library/vstudio/bb386404(v=vs.100).aspx
In other words, the timer will trigger update in panel in that time interval you set up :)
In code behind, every timed event,y ou update your update panel w/ incremental value.
Related
I have some sort of a strange problem, I have an update panel which is triggerd by a timer.
Also I have on this page is a function that calls the DB and retrieves data from it. the function does not being called from the update panel or even related to it.
the problem is that I see in my log file that every time there is a tick and the update panel being updated there is also a call to my DB server (this function is in the page_Load section ) to retrieve the data again. but the page doesn't seem to do a full postback (It stays the same and doesn't looks like being reloaded)
my code:
<asp:Timer runat="server" id="UpdateTimer" interval="5000" ontick="UpdateTimer_Tick" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger controlid="UpdateTimer" eventname="Tick" />
</Triggers>
<ContentTemplate>
<span id="s1" runat="server"></span>
</ContentTemplate>
</asp:UpdatePanel>
and code behind:
protected void UpdateTimer_Tick(object sender, EventArgs e)
{
DateTime dt = TimeConvertor.getCurrentGameTime();
s1.InnerText = String.Format("Current game time: {0:dd/MM/yyyy HH:mm}", dt);
}
The function to retrieve data from the DB is in the page_load of the page.
Any help is appreciated
Thank you
Doron
Using the Update panel doesn't refresh whole page, only controls inside update panel, but when Partial Update is executed all the server page life-cycle events occur, and view-state and form data are preserved, but when rendering page only part of update panel is rendered and returned to user.
Go to this link Partial page rendering
and scroll to the section background.
I want to do page load every 5 sec so I have this in my head content
<meta http-equiv="refresh" content="5" />
Because of this the whole page refreshes. I just want to refresh the gridview and the graph that I have in the page. How can I do that without refreshing the whole page.
<asp:ToolkitScriptManager ID="ToolkitScriptManager1" EnablePageMethods="true" EnablePartialRendering="True"
runat="server">
</asp:ToolkitScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
<ContentTemplate>
<div id="pie">
<canvas width="125" height="450" id="progress1">[No canvas support]</canvas>
<canvas id="pie1" position="relative" width="400" height="400">[No canvas support]</canvas>
</div>
<asp:Panel runat="server" ID="Panel_Users">
<asp:GridView ID="Grid_UserTable" runat="server"
OnRowDataBound="MyGrid_RowDataBound">
<Columns> </Columns>
</asp:GridView>
</asp:Panel>
<asp:Timer ID="TimerClickEvent" runat="server" Interval="4000" ontick="TimerClickEvent_Tick"></asp:Timer>
</ContentTemplate>
</asp:UpdatePanel>
protected DateTime LastUpdate
{
get
{
return (DateTime)(ViewState["LastUpdate"] ?? DateTime.Now);
}
set
{
ViewState["LastUpdate"] = value;
}
}
protected void TimerClickEvent_Tick(object sender, EventArgs e)
{
if (LastUpdate.AddSeconds(5.0) < DateTime.Now)
{
UpdatePanel1.Update();
LastUpdate = DateTime.Now;
}
}
protected void Page_Load(object sender, EventArgs e)
{
ToolkitScriptManager1.RegisterAsyncPostBackControl(TimerClickEvent);
if (!IsPostBack)
{
LastUpdate = DateTime.Now;
}}
Doesn't reload. where am I going wrong
Place the panel inside an UpdatePanel and use method updatePanelID.Update() to update the update the Panel containing GridView. See this for more details
Instead of button click event you can use a timer for that.
If you only want to refresh a region, there are 2 options:
load that into an <iframe> and let it do whatever it wants (via meta-refresh on the document inside the <iframe>
reload the implacted region via javascript, perhaps jQuery's .load() method, i.e. $('#id').load(url);
A meta-refresh on the entire page will, by necessity, reload the entire page.
For a built in asp.net solution, use an <asp:UpdatePanel> along with an <asp:Timer> control.
Set the update panel to update based on the Timers Tick event. This will then only update the content within the update panel.
HOWEVER, this is a quick and dirty solution (in my opinion) because even though the content on the page only updates within the update panel, the whole page is actually posted back each time, and anything within the Page_Load method will be processed again.
Another solution would be to use some javascript ajax, and only update what you need to update. A great javascript library which will help you with this is jQuery, and then use the AJAX features of this. This will allow you to reload on the areas that you need, and give you far greater control over what is happening.
I would forget about the AJAX Control Toolkit, and look more into jQuery Ajax and jQuery UI.
I am writing a card game app using Ajax, c# and .NET 3.5. Due to the nature of the interface I have numerous update panels that Im trying to manage and update across various user action. I'm having problems with one though.
The players current hand is built by binding a list of Card objects to a repeater and then dynamically creating a Card UserControl and adding it to the Controls of a PlaceHolder when each item is databound. The code is roughly as follows:
On the page
<asp:UpdatePanel ID="pnlInHand" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:Repeater ID="rptInHand" runat="server" onitemdatabound="rptInHand_ItemDataBound">
<ItemTemplate>
<asp:PlaceHolder ID="plcInHandCard" runat="server" />
</ItemTemplate>
</asp:Repeater>
</ContentTemplate>
</asp:UpdatePanel>
In code behind
protected void rptInHand_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
Card card = (Card)e.Item.DataItem;
PlaceHolder plcCard = (PlaceHolder)e.Item.FindControl("plcInHandCard");
plcCard.Controls.Add(CreateCardControl());
}
private CardControl CreateCardControl()
{
CardControl cardControl = (CardControl)Page.LoadControl("~/UserControls/CardControl.ascx");
//Set control properties here
return cardControl;
}
The Card Control includes a Button. The ClickEvent for this button calls a Method of the Parent Page that needs to update a seperate UpdatePanel as well as remove the card Control from the Panel that it is sitting within.
I have two issues.
When I click the Card Control Button, because it has been created as part of a repeater within an updatePanel, it no longer exists when the page is posted back and so the Click event for the button within the control never fires. I can obviously rebind the repeater on page load, but does this mean I have to essentially do this on every postback?
More importantly I need a way to trigger the update of another updatepanel in the parent page when the Card control's click event is raised. Is there a way of setting a trigger on an update panel that listens out for an event within a dynamicaly loaded UserControl?
Many thanks
Stewart
Sample code from ASP.net site that should address your point 2 problem follows.
I'll leave the translation to your code to you.
I may be misunderstanding what you are trying to do but I believe once you get this working your issue with point 2 is no longer relevant as you'll get the AJAX postback you want from your parent update panel.
Good luck!
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1" OnItemDataBound="itemDataBound">
<ItemTemplate>
<mycontrol:user ID="user1" runat="server" OnCausePostBack="user1_CausePostBack" /> <br />
</ItemTemplate>
</asp:Repeater>
</ContentTemplate>
</asp:UpdatePanel>
protected void itemDataBound(object sender, RepeaterItemEventArgs e)
{
ModalPopup_WebUserControl mw=(ModalPopup_WebUserControl)e.Item.FindControl("user1");
AsyncPostBackTrigger at = new AsyncPostBackTrigger();
at.ControlID = mw.ID;
at.EventName = "CausePostBack";
UpdatePanel2.Triggers.Add(at);
}
protected void user1_CausePostBack(object sender, EventArgs e)
{
// do something
}
just an idea for point 2 : what about add a property in the cardControl to set a reference to the updatepanel/s ? from there you can add triggers or call panel.update in the button event
for point one yes u will have to do it. u will have to re create the controls
for point 2 a simple updatePanel.update() would do the job insode of any event if you are using an event that was binded to a dynamically created control then u will have to rebind the event on every page postback
I need some help with this problem:
Situation:
I've got a usercontrol (in SharePoint) that reads query string and processes it with an asynchronous event. While it's busy, a spinner is shown. After the event is finished, the updatepanel inside the usercontrol should update and show the message (+ hide the spinner)
Code: I've got a function that's called asynchronously on the UserControl_Unload event.
private delegate void AsyncFunction(string activation);
void UserControl_Unload(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
AsyncFunction dlgt = new AsyncFunction(this.CheckUrl);
AsyncCallback callback = new AsyncCallback(FunctionCallBack);
IAsyncResult ar = dlgt.BeginInvoke(activationcode, callback, null);
}
}
private void CheckUrl(string lalala)
{
// Some code
}
User control markup:
<asp:UpdatePanel runat="server" id="pnlContent" updatemode="Conditional" ChildrenAsTriggers="true">
<ContentTemplate>
<asp:UpdatePanel runat="server" id="pnlStatus" UpdateMode="Conditional" ChildrenAsTriggers="false">
<ContentTemplate>
<asp:Label runat="server" ID="lblMessage" />
<asp:LinkButton runat="server" ID="btnHome" Text="Terug naar welkom-pagina" PostBackUrl="<% $SPUrl:~sitecollection %>" />
</ContentTemplate>
</asp:UpdatePanel>
<asp:UpdatePanel runat="server" id="pnlGegevens" UpdateMode="Conditional" ChildrenAsTriggers="false">
<ContentTemplate>
<div><asp:Image runat="server" ID="imgLoading" AlternateText="Loading..." CssClass="gb_pl_loadingImage" ImageUrl="<% $SPUrl:~sitecollection/Style Library/GB-VW Styles/Images/ajax-loader.gif %>"/></div>
<div class="gb_pl_loading">Even geduld aub. De gebruiker wordt geactiveerd...</div>
</ContentTemplate>
</asp:UpdatePanel>
</ContentTemplate>
</asp:UpdatePanel>
This all works great, but when I need to update the panel, it doesn't work.
private void FunctionCallBack(IAsyncResult test)
{
pnlContent.Update()
}
Anyone who knows how to solve this? (if it's possible only use asp, c# or javascript)
Is it possible to fire off the asynchronous operation from the client? That is, display your page but include javascript that makes a webservice call? That way you at least have something to wait for, and your client will get notified becuase it initiated the request.
Otherwise I don't see how the page, which is already gone to the client, could be updated by the server once the async op finishes.
I'm trying to make an webapplication where you see an Ajax countdown timer. Whenever I push a button the countdown should go back to 30 and keep counting down.
Now the problem is whenever I push the button the timer keeps counting down for a second or 2 and most of the time after that the timer keeps standing on 30 for to long.
WebForm code:
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="geen verbinding"></asp:Label>
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
<br />
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />
</Triggers>
</asp:UpdatePanel>
<asp:Timer ID="Timer1" runat="server" Interval="1000" ontick="Timer1_Tick">
</asp:Timer>
</form>
Code Behind:
static int timer = 30;
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = timer.ToString();
}
protected void Timer1_Tick(object sender, EventArgs e)
{
timer--;
}
protected void Button1_Click(object sender, EventArgs e)
{
timer = 30;
}
Hope somebody knows what the problem is and if there is anyway to fix this.
Thanks in advance!
since timer is processing the page asynchronously, and the button click event takes time for processing on the server, the timer event still fires in between the button click event and hence the timer keeps counting back for a second or two. Use Java script to set the label to 30 on client side as soon as the reset button is clicked. Upon timer click event, decrement the label value (not the timer) and assign to the label the new value. No need for timer int variable. Also on page load, assign the label value only if the page is not postback (i.e. IsPostback is false) as we want to load label value only on first time the page is rendered. Rest of the time, the timer click event will assign the value.
The problem was that Visual Studio hosted it on localhost. If you use ip-adress 127.0.0.1 instead of local host within the URL it worked fast. I guess this won't be a problem on faster machines, sadfully I had none at that time.
EDIT: Adding a bounty on this question was a mistake, sorry about that.