I have code that seems to defy explanation. There are a couple of pages that do some data maintenance in our web application (VB.net codebehind). One works as expected, the other has a problem.
They both have an Ajax Tab Container to group the appropriate parts of the data. When I hit the 'Save' button, I want the page to remember what the active tab was. In the first page, there's no problem. I get the postback, go through the Page_Load and everything works as expected.
For some reason, on the second page, when I click the Save button, which is defined exactly the same as on the first page, I get the "POST" that I expect (Request.RequestType = "POST") but then Page_Load gets fired AGAIN with Page.IsPostback being "False" (Request.RequestType = "GET") - like I just clicked into the page.
The button markup is simple the only difference is that one is in a table and the second is in it's own <div>
:
<asp:TableCell ColumnSpan="2" HorizontalAlign="Center">
<asp:Button ID="btnSave" runat="server" Text="Save" Width="2in" />
</asp:TableCell>
<center>
<asp:Button ID="btnSave" runat="server" Text="Save" Width="4in" Height="0.33in" />
</center>
The markup at the top of the pages is identical - just the required properties with AutoEventWireup and EnableEventValidation as "False" and MaintainScrollPositionOnPostback as "True".
I can't understand why these two pages are giving me such difference results. With the .aspx markup being so similar, it's easy to spot any differences. How can I figure out where this phantom "GET" is coming from?
Related
I have a weird problem in my page. I have a button called Print. I wanted report should come in a new tab, so i wrote some javascript on button's onClientClick. Which works great with no problem at all.
But problem starts now when user comes back on original page again, now here i have several controls which cause postback. Say for example its a dropdownlist. so whenever user changes dropdown item it causes postback which is fine but everytime it opens a new tab on every postback.
hope I am clear in question...
Any help??
Here is a code:
<asp:Button ID="btnshow" runat="server" Text="Show" Font-Bold="true" ForeColor="Black" Width="90px" OnClick="btnshow_Click" OnClientClick ="document.forms[0].target = '_blank';"/>
The issue is document.forms[0].target='_blank' is setting the target on the form not the individual button so a postback triggered by any control will open in a new tab.
You should use a HyperLink control instead of the Button control. The HyperLink control has a Target property which allows you to specify how the link should be opened.
Below is an example taken from the HyperLink documentation. This will render an anchor tag with target="_blank".
<asp:HyperLink ID="lnkPrint" NavigateUrl="http://www.microsoft.com" Text="Print" Target="_blank" runat="server" />
I have a set of options on an ASP.net page where the user may open up one of two lightboxes - either the "Add" lightbox or the "Edit" lightbox.
Each one has a small form for the user to fill out, and then they can hit a button at the bottom of the lightbox to hit submit.
I have the buttons set up within the lightboxes like so:
<asp:Button Id="btnSubmitAdd" runat="server" Text="Submit" OnClick="btnSubmitAdd_Click" />
... then later in the other lightbox...
<asp:Button Id="btnSubmitEdit" runat="server" Text="Submit" OnClick="btnSubmitEdit_Click" />
When i click the "Add" lightbox's submit button, everything behaves just fine.
When i click the "Edit" lightbox's submit button however, it fires "btnSubmitAdd_Click" instead of its own "...Edit_Click" event!
I have checked and re-checked all of the names and events and everything is set up correctly. Anyone have any ideas why this is happening?
Thanks to #MikeGuthrie for leading me down the correct path!
The issue seems to be with asp.net defaulting buttons to type "submit" which submits the entire form, and apparently that means it simply hit the first button's event before the second.
I added have modified the buttons like so and things are working now:
<asp:Button Id="btnSubmitAdd" runat="server" Text="Submit" OnClick="btnSubmitAdd_Click" UseSubmitBehavior="false"/>
<asp:Button Id="btnSubmitEdit" runat="server" Text="Submit" OnClick="btnSubmitEdit_Click" UseSubmitBehavior="false"/>
I read Microsoft's article on ASP.Net Page Life Cycle events. It confused on one thing. When Page_PreInit gets called, all the controls' Init method is not yet called. When I setup a test project, I observed a different behavior. In the mark up, I created asp label and button controls and set certain properties such as Text. I put a break point at the beginning of Page_PreInit. When break point got hit, I checked if the controls got created or not by referring to them by their Ids in the Watch window. They all existed and none returned null. Then I checked the Text property and it was what I set in the mark up. So doesn't this contradict what Microsoft says? If this is the case what do Controls' Init method do if they are already initialized? Is there something I miss?
I created asp label and button controls and set certain properties
such as Text. ... Then I checked the Text property and it was what I set
in the mark up.
If you set property value at Design Time, they are in control tree so properties are available in all events.
However, if you add a TextBox and a user clicks on submit, TextBox Text Property only start available at Page_Load event.
The reason is that Page_Load is the place where properties are loaded with information recovered from view state and control state.
Look at this example
<asp:Label runat="server" ID="Label1" Text="Name" />
<asp:TextBox runat="server" ID="TextBox1" />
<asp:PlaceHolder runat="server" ID="PlaceHolder1" />
<asp:Button runat="server" ID="SubmitButton"
Text="Submit" OnClick="SubmitButton_Click" />
After Postback,
Notice that you can only retrieve TextBox value at Page_Load event.
I have an ASP.NET form with a few controls and a submit button at the bottom, all inside an update panel:
<asp:UpdatePanel runat="server" ID="upContent">
<ContentTemplate>
<asp:TextBox runat="server" ID="tbxMyTextBox" AutoPostBack="true" />
<asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClientClick="return doStuff()" OnClick="btnSubmit_Click" />
</ContentTemplate>
</asp:UpdatePanel>
If I write something in the TextBox and click 'submit' immediately (without clicking out of the TextBox first), the changes are not recorded (as seen in the server-side event handler). However, if I write something in the TextBox, and then change focus to another control, an AutoPostback happens through the UpdatePanel and then clicking 'submit' does recognize these changes. How can I force this content to update right as I click the submit button, while still running both the clientside and serverside events attached to it? Thanks!
Is is possible that your text-box gets cleared due to some on-submit/on-click event handler? I will suggest you do use some tool such as Fiddler to inspect the POST data in request. Or you can put a break-point at your server side code and inspect the request data. Look for particularly Request.Form[tbxMyTextBox.UniqueID] - i.e. look for presence of value for your text-box's name (name property at client side which corresponds to UniqueID property at server side). If the request contains the value typed in the text-box then something is happening on server side but good news is you can always retrieve the value from Request object. If the value is not present in the Request object then it means that client side code is clearing the value before the submit.
If an onclick method returns false, it cancels the action that the button would normally perform. As your button would normally submit your form, but it appears not to be submitting, your client side javascript code in doStuff is probably returning false.
I have a page with different placeholders. In one of them, I have a link that I want to open a modal popup in a second placeholder (using the ajaxtoolkit ModalPopupExtender) :
<asp:Content ID="content1" ContentPlaceHolderID="placeholder1" Runat="Server">
<asp:LinkButton ID="link" runat="server" Text="Popup link" />
</asp:Content>
<asp:Content ID="content2" ContentPlaceHolderID="placeholder2" Runat="Server">
<asp:Panel ID="panel" runat="server" Text="Popup content" />
<ajaxToolkit:ModalPopupExtender ID="popup" runat="sever"
TargetControlID="link"
PopupControlID="panel"
/>
</asp:Content>
When doing as above, it fires me an exception, saying that popup cannot find link (which I understand, because they are in two different placeholders).
How can I make this work ? I can think of something find FindControl in the code behind, but I don't really like to use this function, as it is pretty computationally expensive (especially with my nested layout).
One issue is that your TargetControlID and PopupControlIDs are reversed. TargetControlID is the ID of the item that you want to 'Modal Pop', in your case that would be Panel1. The PopupControlID is the ID of the control that would trigger the ModalPopup, in your case that would be "Link"
But you still have a few options if that doesn't work, I have fired a modal located in a different update panel before using the method below. Though not the exact same issue, this workaround may help you (I am assuming you have a script manager on your page).
Create a hidden element in Content2 with ID="hiddenLink"
Set your ModalExtender PopupControlID="hiddenLink"
In the codeBehind for "link" in content1, add an onClick event with the following
ModalPopup1.show()
If you are using updatePanels, this will cause the ModalPopup to display in AJAX fashion without page refresh.But you would still get a full postback worht of data between the client and the server.
Method 2, you could use a javascript function to show to Modal as well. Add a behaviorID="MyModal1" (or whatever you want to call it) to your Modalpopup definition. Then change your link:
<asp:LinkButton ID="link" runat="server" Text="Popup link" OnClientClick="$get('MyModal1').show(); return false;"/>
Note: The return false in the above example prevents the .NET page from performing a postback.