Question

7

Partial postback with Javascript

rated 0 times [ 12] [ 5] / answers: 1 / hits: 39118 / 14 Years ago, tue, october 19, 2010, 12:00:00

I couldn't find something similar in SO.

In ASP.NET, is there any way that on cue I can cause a partial postback with Javascript in an UpdatePanel?

I tried __doPostBack() but it does a full postback.

I can trick it with a dummy button and fire click() then handle the partial postback that way, but I want a more graceful way than trickery.

Thanks.

Edit: I found this disturbedbuddha.wordpress.com/2007/11/26/… but I can't get it to work =(

I would love for this method to work; it's perfect for me!
So far what I can do using this last method is gain reference to the timer. With the timer initially disabled, starting the timer doesn't seem to cause a postback. However, without Ajax, if I simply have the timer enabled initially, it posts back at intervals just fine; why can't the Ajax call cause it?

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

rayvencallij

Add To Favorites

Follow

Total Points: 93

Total Questions: 80

Total Answers: 85

Location: Argentina

Member since Thu, Mar 18, 2021

3 Years ago

answered 14 Years ago joanneamiyaa · Accepted Answer

You can use an AsyncPostBackTrigger with the UpdatePanel to do this. Because you need something that can fire an event, using a button is fairly simple and when hidden works nicely.

If this is your markup:

<asp:UpdatePanel ID=UpdatePanel1 runat=server OnLoad=UpdatePanel1_Load>

    <ContentTemplate>

        <!-- Contents... -->

    </ContentTemplate>

    <Triggers>

        <asp:AsyncPostBackTrigger ControlID=ReloadThePanel EventName=Click />

    </Triggers>

</asp:UpdatePanel>

<asp:Button ID=ReloadThePanel runat=server style=display:none; />

When you want the panel to be updated, you just need to call:

__doPostBack('<%=ReloadThePanel.ClientID %>', null);

This will make ASP.NET think that ReloadThePanel was clicked and the JavaScript auto-generated due to the trigger will handle the rest.

EDIT

You can do a pure JavaScript update of the UpdatePanel without any triggers or hidden buttons. You just need to invoke __doPostBack with the client-side ID as the first argument.

__doPostBack('<%=UpdatePanel1.ClientID %>', null);