Partial postback with Javascript
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 t开发者_如何学Goimer enabled initially, it posts back at intervals just fine; why can't the Ajax call cause it?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);
I used @MatthewJacobs' answer but I found that the call to __doPostBack
caused a runtime exception on IE11. I found that the call to __doPostBack
can be replaced by the following JavaScript call, which worked on both browsers I tested (IE11 and Chrome 52).
Sys.WebForms.PageRequestManager.getInstance().beginAsyncPostBack(
[ '<%=UpdatePanel1.ClientID %>' ], '<%=UpdatePanel1.ClientID %>', null
);
See Sys.WebForms.PageRequestManager.beginAsyncPostBack Method for more details.
The solution that worked for me
ASPX
<script>
function myfunc(){
__doPostBack('<%=UpdatePanel2.ClientID%>', "");
}
</script>
<asp:UpdatePanel ID="UpdatePanel2" runat="server" OnLoad="UpdatePanel1_Load">
</asp:UpdatePanel>
.cs
protected void UpdatePanel1_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
//your code
}
}
精彩评论