Difference Between Adding Code In The PreLoad Event Handler And At The Top Of The Load Event Handler?
Oct 3, 2010
Is there a technical reason for the existence of Page.PreLoad or is this just convenience to have a place where you can neatly place code that always have to be executed before the Load code? Is there a difference between adding code in the PreLoad event handler and adding code at the top of the Load event handler? And what would be a typical scenario where you use PreLoad?
I'm working in 2008 and cannot find out how to simply add the preload event to the code behind. In 2005 I just simply double clicked on the event in the list and it would set it up for me.
I understand I need to load my dynmaic control on every postback and preferrably in Page_Init(). But my dyanmic controls are loaded from a dropdownlist selectedindexchanged event handler. Now after any postback, my dynamic controls are gone. How would I force it to load on every postback ?
When I write the code for Each HtmlAnchor a in Me.Master.FindControls("link" + i) AddHandler e.OnServerClick, AddressOf OnClick end for I get an error that OnServerClick event is protected and I cannot access it. The question is how do I dynamically add event handlers to HtmlAnchor controls?
I will describe my problem in simple way so it's not exactly what I'm trying to do but the idea is the same.Here is the problem:
I create dynamic buttons from code behind.I get some id from query string,create button with that id ,dynamic add event handler to click event,and add button to placeholder.I store the list of id-s in session and in page load method recreate these buttons and add to placeholder.One of the id-s is CurrentId and it's also stored in session.Buttons click handler do something like this
In page load when I create buttons I want to set button text property different from others if id==Convert.ToInt32(Session["CurrentId"]) when list of id-s are gotten from session.But problem is that click event handler is called after page load,and when I create buttons in page load ,CurrentId in session hasn't been channged by click event handler.Can you suggest any solution to this situation?
I have a GridView control that contians, among other things, a DropDownList. In this particular case, the DropDownList is in the EmptyDataTemplate, but I suspect I will run into a similar situation when I'm in Data Rows as well.I'm trying to handle the OnSelectedIndexChanged event for the DropDownList and in the .aspx file I have used the declarative syntax to assign the handler OnSelectedIndexChanged="ddlStoreList_SelectedIndexChanged") and have created the handler code to deal with this.
[Code]....
The problem that I'm running into is that the event is not being handled. In other words, when I put a breakpoint in the handler, I find that it is not getting hit when I change the selection of the DropDownList.
in my asp.net website, i have textbox control inside datagrid control. I would like to add textchange event in javascript where i need to sum the values inside textboxes in datagrid and show that addition in lable outside grid. I would also like to do same addition in codebehind(*.cs) But codebehind only execute when browser not support javascript. It means when browser support javascript only client side javascript should execute not server side code
I have a page books.aspx that has a control named authors.ascx.
Inside the authors control there is a "select" button I want to add some kind of listener or event handler (not sure of the correct terminology) so on the parent page (books.aspx) I can respond to the "select" button being clicked.
I have to pass the authorID from the user control to the parent page.
In my authors.ascx control I just created this event:
[Code]....
Now I need to write the function for SelectAuthorBtnClick and I think add some kind of listener in the parent page to listen and handle the event.
When I click on the aspx Submit Button, the file selected in Silverlight control should be uploaded and after the completion of upload, the Server side event should get called.
i have two frames in a page. the fist one contains buttons the second one the form. i want to call an event from the second one after clicking a button in the first one ,
This event handler is not responding at all to the click event. On click, the pagination numbers disappear and I'm not able to trace it in the debugger because the event handle doesn't even fire so I have no idea what's going on.
I get an error when attempting to navigate to the page containing this gridview. The error is 'SelectPackage_Click' is not a member of 'ASP.offer_aspx'.
here my page directive:
[Code]....
Here is my markup. Eventhough SelectPackage_Click is present in the code behind, it is not wired up with the button control.
Found this question on an interview siteGiven the following methods of the ASP .Net Page class, in which of them would you attach an event handler to an event published by a control on the web page?
I've created a database table with a bunch of links I'm going to use in my program. All seems fine, except for the onClick even handler, which doesn't work as a string. Anyone got an idea how I can set it? There's no constructor for EventHandler accepting a string...
In desktop programming, I can usually find out which control has fired an event via using the following coding:
[Code]....
However in ASP.Net, button derives from System.Web.UI.WebControls.Button an does not feature an extension method for Name, therefore can anyone come up within something similar that will work in ASP?
I am creating a web control by addin the html in the code behind, like this:
Code: Dim sb As New StringBuilder Dim myDiv As HtmlGenericControl = Me.theContainer sb.Append("<table width='100%' cellpadding='0' cellspacing='0' style='border:0px;'>" & vbCrLf) sb.Append(" <tr class='mainRow1'>" & vbCrLf) sb.Append("<td align='left' style='border:0px solid white;'>Main Menu</td>" & vbCrLf)
[Code] ....
This will generate the html for the table in the codebehind then inject it into the specified DIV element. My question is, if I create a control in this manner, how do i add an event that will fire a method in my codebehind? For example, if i want to create a image button i would do it this way in the code:
Code:
<asp:ImageButton CommandArgument='<%# (Container.DataItem.objectValue) %>' ID='ImageButton1' runat='server' OnCommand='Button1_Click' ImageUrl='~/images/folder.gif' /> but in the code behind i would do this:
I have a page request with a QueryString, say [URL]. The page is displayed in a browser. Now there is an asp:LinkButton on the page which should enable the user to open the page without the QueryString (as if he had entered [URL] directly in the browser's address bar). I had two ideas:
1) Use the PostBackUrl attribute of the LinkButton: <asp:LinkButton ID="LinkButton1" runat="server" Text="Select" PostBackUrl="~/Orders.aspx" />
2) Use "RedirectUrl" in an event handler: <asp:LinkButton ID="LinkButton1" runat="server" Text="Select" OnClick="LinkButton1_Click" /> and protected void LinkButton1_Click(object sender, EventArgs e) { Response.Redirect("~/Orders.aspx"); }
In both cases the browser's address bar shows [URL] without the QueryString, as I like to have it. But in the first case the page does not change at all. But it should, because I'm evaluating the QueryString in code-behind and control the appearance of the page depending on whether a QueryString exists or not. The second option works as intended. If I am not wrong the second option requires an additional roundtrip:
Browser sends request to server Event handler on server side sends Redirect URL to browser Browser sends again request to the server, but with the new URL Server sends new requested page to browser
Whereas the first option omits the first two steps in the list above, thus saving the additional roundtrip and resulting in: Browser sends request to the server, but with the new URL (the PostbackURL specified in the LinkButton) Server sends new requested page to browser. Do I really need this second roundtrip of option (2) to achieve what I want?
Currently I am implementing code from this example. In my aspx file, I have Label1 and Textbox1 defined. In my aspx.cs file, I am setting the Label1.Text property to a random string in the Page_Load method.
In the .js file I have included, I have: var Label1, TextBox1; Sys.Application.add_init(AppInit); function AppInit(sender) { Label1 = $get('Label1'); TextBox1 = $get('TextBox1');
Page One is a home page, where I'm providing another version of that dropdown. I'd like the change event in this case to redirect control to Page Two, and then execute the event handler.
My cheap solution is just a Redirect with a querystring value that is handled on page load.
I am wondering how to add a javascript event handler using asp.net ajax. I need to add event handlers after ajax update because Jquery plugin to sort tables doesn't work and the onload method to display a screen keyboard does not trigger as well. Is there a way to do that? Maybe I need to switch to some other ajax library or/and try Asp.Net MVC to accomplish?
I have a page that contains dynamically generated Dropdown List controls and I want thant the dynamic dropdown list perform an AutoPostback to fill some other field using the value selected. This is the code I'm using to create dynamically the control:
[Code]....
Control is correctly filled and rendered on ASP page but, after selecting a value, the page is reloaded (AutoPostBack is called) but the control is not diplayed and the sub is not called. I put a breakpoint into the ChangeValue sub but anything happens.
I read on some post that handler for the first DropDownList is not necessary but, how is it possible to tell DropDownList to call my sub after changevalue?
