How to trigger UpdatePanel from a GridView TemplateColumn click? - asp.net

I have the following case, all my controls on an update panel on the page.
One of these controls is a GridView, this GridView contains a CheckBox on the header template field (to make a check all). The autopostback is true but when the check changed no thing is changed, the update panel has a trigger asynchronous post back for the GridView.

I just fixed this bug after searching everywhere and tried the last solution here with no success. So I first created an OnClick event in the CheckBox. In the Onclick function in the .cs file, make a call to the SelectedIndexChanged(new object(), new EventArgs()); method with arguments as given then just after call the Update method to your UpdatePanel.

You'll have to define an ASyncPostBackTrigger like so:
<asp:UpdatePanel>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="yourCheckBox" />
</Triggers>
<ContentTemplate>
...GridView etc
</ContentTemplate>
</asp:UpdatePanel>

Related

How do I force asp.net page to postback when I'm in code behind that called by UpdatePanel

When an UpdatePanel Calls a method in server and for example this method change
textBox1.Text = "12312"
and this textBox1 was out of updatePanle scope
it dosn't change it text till a postback happend to the page
so I need after that calculation and chaging the Textbox's text in the server, I need to forcepage to do postback
plz can any one help ?
If you want to force a refresh you could try: Response.Redirect(Request.Url.AbsoluteUri)
This should force a redirect to the current page.
Hope this helps
If you wish for a control within the UpdatePanel to perform a standard postback, define a PostBackTrigger within the UpdatePanel, setting the ControlID to the ID of the control you wish to perform the postback.
<asp:UpdatePanel ...
...
<Triggers>
<asp:PostBackTrigger ControlID="ControlIDToPostBack" />
</Triggers>
</asp:UpdatePanel>
Or you could add the TextBox control you wish to update to another UpdatePanel setting both of the UpdatePanel's UpdateMode properties to Always.
This will ensure that the content within both UpdatePanel controls is updated for all postbacks that originate from the page. Which includes asynchronous postbacks.
<asp:UpdatePanel ... UpdateMode="Always"

Postback in UpdatePanel

I have made a ToolBar usercontrol in a update panel. All buttons should work client side except a print button. I want to make this use the original postback.
ScriptManager.GetCurrent(Me).RegisterAsyncPostBackControl(Toolbar2.PrintButton)
However the button still doesn't refresh the page...
Any ideas?
You must set AutoPostBack to true? of the PrintButton that you have created
Rather than using the script manager to register a control as asynchronous, instead set the button as a trigger on the update panel itself, which you also can do via code.
HTH.
When you use RegisterAsyncPostBackControl you must also manually refresh the update panel using the Update() method.
http://geekswithblogs.net/lszk/archive/2011/08/08/playing-with-update-panels.aspx
You can use the Triggers property of the UpdatePanel to register actions that trigger a full postback.
Add a PostBackTrigger object to that property, containig the ControlID of the control which needs to trigger a full postback.
<asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
<ContentTemplate>
...
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="myFullPostBackControlID" />
</Triggers>
</asp:UpdatePanel>

UpdatePanel inside a Repeater - update all rows

I'm trying to speed up my Repeater so that not as much HTML has to be resent via the AJAX UpdatePanel on each call.
So here's what I have (a very much simplified version):
<asp:Repeater ID="rptContactSteps" runat="server">
<ItemTemplate>
<p>Script:<br /><%#mobjSDIT.FormatText(Eval("script"))%></p>
<p>Notes:<br /><%#mobjSDIT.FormatText(Eval("notes"))%></p>
<asp:UpdatePanel ID="upStep" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="rptContactSteps" EventName="ItemCommand" />
</Triggers>
<ContentTemplate>
<p>Contact/Step Notes:<br /><%#mobjSDIT.FormatText(Eval("contact_step_notes"))%></p>
<asp:ImageButton ID="btnSaveAndCompleteLastStep" runat="server" ImageUrl="~/images/content/buttons/save-and-complete-button.png" CommandArgument='<%#Eval("step_contact_tie_id")%>' />
</ContentTemplate>
</asp:UpdatePanel>
</ItemTemplate>
</asp:Repeater>
So, when I click 'btnSaveAndCompleteLastStep' I want all the UpdatePanel in 'rptContactSteps' to update. Having the UpdatePanel inside the ItemTemplate should help prevent having to re-load the html/text that populates the Eval("script") & Eval("notes"), since the value of these variables could be very large and over a 3G connection this could be very costly (in time & money).
I though by adding the async trigger it'd work as I have used this type of trigger before, but not when inside the Repeater. Currently the UpdatePanels aren't getting updated at all, except from the one from which the button was pressed.
Any ideas anyone?
They aren't getting updated except by the one that is called because the update mode is set to conditional, and by default the ChildrenAsTriggers is set to true. So if you want them all to update when one of them is changed, then you will need to find each of the update panels in each of the repeater items and call .Update() on the update panel, or you can change the update mode to "Always", or just wrap your repeater in an update panel instead of wrapping just the items.
Does that make sense? If not I can expand.
That behavior sounds ok to me because postback from within an updatepanel will not update anything outside of it by default.
One way you can try is on your btnSaveAndCompleteLastStep click , find each updatepanel in the repeater items and call Update() on it.

Asp.net Update Panel

I am working in asp.net 3.5 and have some issue of update panel.I have some html content and Formview control in a page. I want to hide the html content when there is no data in the Formview and to show when there is data in the Formview control. My Formview control is in the updatepanel and it it is bind to SqlDataSource and Formview binds on some criteria.
If somebody know how to solve this issue then please help me.
If you want the HTML content to be hidden after an Ajax postback, it will need to be in an UpdatePanel, either the same one your FormView is in, or a separate one.
If it's in a separate one, you'll need some way of forcing it to update when the FormView updates. You can either do this in some code-behind, calling the Update() method of the UpdatePanel, or by adding an AsyncPostBackTrigger to the UpdatePanel containing the HTML, maybe using the DataBound event of the FormView.
Also, to easily hide the HTML content, put it in a Panel, and use the Visible property.
An example of the trigger:
<asp:UpdatePanel ID="updatePanel" ... runat="server">
<ContentTemplate>
...
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="formViewId" EventName="DataBound" />
</Triggers>
</asp:UpdatePanel>
This issue simply resolved using the putting all the html content in the Updatepanels and on UpdatePanel_preRender event of Updatepanels check that if Gridview has data then show html content otherwise hide

Trigger an update of the UpdatePanel by a control that is in different ContentPlaceHolder

I have a page with two ContentPlaceHolders. One has a DropDown and another UpdatePanel with content.
How can I trigger update to the UpdatePanel by the DropDown's selectedItemChanged event when they are in different ContentPlaceholders?
The following would not work since UpdatePanel1 doesn't know about DropDown1:
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true">
<ContentTemplate>
Some content that needs to be updated here...
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="DropDown1" EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
One way is to make an ajax page method that would be called by javascript on the page when DropDown's item is selected. Then in code behind, inside that page method, call UpdatePanel1.Update().
Is there an easier alternative?
From http://msdn.microsoft.com/en-us/library/system.web.ui.asyncpostbacktrigger.aspx
The control that the
AsyncPostBackTrigger references must
be in the same naming container as
the update panel for which it is a
trigger. Triggers that are based on
controls in other naming containers
are not supported.
The workaround is to use the UniqueID of the control that the
trigger is referencing. Unfortunately the UniqueID isn't qualified
until the control has been added to its parent (and its parent
has been added to its parent, all the way up the control tree).
In your code behind, try:
UpdatePanel1.Triggers.Add(new AsyncPostBackTrigger()
{
ControlID = DropDown1.UniqueID,
EventName = "SelectedIndexChanged", // this may be optional
});
In the code-behind file, you should be able to do:
ScriptManager.RegisterAsyncPostBackControl(dropdown1);
You can enforce update any of page UpdatePanels by call updatePanel1.Update() method on server side.
For example during update updatePanel1 on button1.Click call updatePanel2.Update() and both panels will be updated.

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