Does there exist a solution for this scenario?
I have a content page which contains an UpdatePanel and has a combobox. When the combobox value is changed I want to change a label in my Master page. So, the main problem for me is that I don't want to make a full postback with every combobox value changing. Is there some trick to overcome full postback?
Thanks in advance.
Put your label in your MasterPage in a separate UpdatePanel.
On dropdownlist's SelectedIndexChange make an asnychronous postback
From the SelectedIndexChanged-Handler call a function on Masterpage(f.e. ShowMessage) that changes the Text of the Label and calls Update on the Masterpage's UpdatePanel.
You can access your MasterPage's functions in the following way(from ContentPage just as UserControls in ContentPage):
((MyMaster)this.Page.Master).ShowMessage(text);
in VB.Net
DirectCast(Me.Page.Master, MyMaster).ShowMessage(text)
Of course you have to replace MyMaster with the actual type of your MasterPage and implement a public function(sub) that changes the Label's Text(ShowMessage in this example) and updates the UpdatePanel in the MasterPage. Set its UpdateMode property to Conditional and make sure that the ChildrenAsTriggers property is false and that no explicit triggers are defined for the panel.
Related
I have a master page where an update panel contains the main placeholder of the content pages.
Inside one of the content pages I need to disable the update panel in any way since I have a form with asp:fileupload control that is always returning null due to the update panel.
How can I overcome this issue?
Place your fileuploader and submit button in another update panel and add a post back trigger for this update panel.
On page load of content page, try to get the update panel of master page using FindControl method and then attach your file upload as a post pack trigger to it dynamically.
That may work
I've got a bad news for you.!
Have a look at this
http://ajax.asp.net/docs/overview/UpdatePanelOverview.aspx
The following ASP.NET controls are not compatible with partial-page updates, and are therefore not supported inside an UpdatePanel control:
TreeView and Menu controls.
Web Parts controls. For more information, see ASP.NET Web Parts Controls.
FileUpload controls when they are used to upload files as part of an asynchronous postback.
GridView and DetailsView controls when their EnableSortingAndPagingCallbacks property is set to true. The default is false.
Login, PasswordRecovery, ChangePassword, and CreateUserWizard controls
whose contents have not been converted to editable templates.
The Substitution control.
Validation controls, which includes the BaseCompareValidator, BaseValidator, CompareValidator, CustomValidator, RangeValidator, RegularExpressionValidator, RequiredFieldValidator, and ValidationSummary control.
Solution :
You may want to use Ajax FileUpload using Jquery in place of update Panel. Remember, Open source is always a better option. :)
I've three images. I use javascript to mark which one is selected. After user clicks on one I change its class to active. its <li><a>. Now when I wasn't using updatepanel after form post I could see from code behind which element is active and it was correct. After adding updatePanel which contains entire form after postback which should refresh content of updatePanel value is wrong and active is always set to default first <a>. Whats more in this updatePanel there is UploadFile control which doesn't work well because it always has HasFile value to false even though I choose file.
Thanks You for any hints
Your form must be a full postback. You have to add a Trigger for the Full postback, if your FileUpload control is in the update panel.
Alternatively if you want to upload Asynchronously , you could try AJAX AsyncFileUpload control
http://asp.net-informations.com/ajax/ajax-AsyncFileUpload.htm
This is a well known problem, please take a look into the following article:
http://geekswithblogs.net/ranganh/archive/2008/04/01/file-upload-in-updatepanel-asp.net-ajax.aspx
I have a custom control that has an update panel in it. Within the update panel, there are no custom controls, but there are custom controls outside the update panel. All controls have an ID set as do the parents of the controls. Inside the update panel is a repeater that has controls that should trigger an async postback. The update panel has an update mode of conditional and children as triggers is off. The update panel renders standalone divs, not table cells. EnablePartialRendering is on on the script manager.
Each repeater item has numerous textboxes, but two of them have autopostback turned on. Inside the repeater ItemDataBound event, I register the control with the script manager's RegisterAsyncPostBackControl.
If I edit either textbox, it does a callback correctly. But after the first one is edited, if you edit the other one, it does a full postback. It doesn't matter which one is done first. But after it's done its postback, if you edit either of the textboxes, it does callbacks correctly.
I've tried several things like changing the UpdateMode and ChildrenAsTriggers properties to various combinations. Nothing seems to work.
Any suggestions?
A lot of things can cause this, compare UpdatePanel causes full page postback with LinkButton in ListView in UpdatePanel causes full postback.
You'll need to provide more information, e.g. .NET Framework version, IIS version etc. exact ASP.NET markup etc
But since you asked for "Any suggestions?" try looking through these questions
I have a UserControl which contains voting buttons inside an UpdatePanel, and outside a Repeater, it works perfectly. In the repeater, clicking the button fires off the appropriate event. That event is supposed to update the text of a control within the User Control, and that update should be reflected when the UpdatePanel refreshes.
If tried the UpdatePanel in UpdateMode Always and Conditional (firing the Update event after making the changes to the properties in the _Click method, and the same problem happens both ways.
Is there something about how UpdatePanels behave in Repeaters that I'm missing?
Thanks.
The reason might have nothing to do with the update panel, but with the postback loosing track of your UserControl. Possibly assigning unique IDs to your user controls may help.
Your repeater is building a table correct? The problem is most likely that an update panel generates a div tag and it's probably outside any TR and TD tags so the browser doesn't know what to do with it.
http://www.netortech.com/blog/?articleid=8
I am trying to access the Text property of a textbox from a partial postback-done in an Update Panel. The problem is that this textbox I want to access is not in this Update Panel, and when I am trying to write to it (putting content in the Text property), this new content is not being displayed.
I think that this is because this textbox is not part of the Update Panel's, but I'm not sure about it. And also, I cannot put this Textbox in the same update panel as the one I'm triggering a partial postback.
Why isn't the text being displayed?
During a partial page rending only controls contained within an update panel will have thier html refreshed. The rest of the page will remain the same.
For your specific case you would need to wrap your text box in an update panel, then you hnave a decision to make. You can either mark its UpdateMode as Always or Conditional. If you mark it as always then all the controls contained within that update panel will get updated durning every partial rendering. If you mark it conditional then you will need to call the update panels Update() method to have it's html refreshed.
I don't think you can, unless you put the text box in a second update panel with the update mode set to Conditional. Then you invoke the update method or set the first update panel as an asyncpostbacktrigger to the new one.
What you are trying to do cannot be done unless you put the textbox in question inside another update panel.And if you want to use the contents of your textbox under other events then set the updatemode for the new updatepanel to always. But if you want to access its Text property only during the event which is the trigger for your other update panel then set the updatemode to conditional and also set the triggers of both the panels as same...
If you are not sure about triggers and updatemode (basically how it works) then just set updatemode to always in both updatepanels and forget about the triggers.
It will work fine then...