Usercontrols - How To Add A New Javascript From A User Control Loaded By Callback
Sep 10, 2010
I'm doing a menu that loads levels dynamicly, when you click on a item the next level is loaded asynchronously. For each menu item I have a user control. Every user control is declared in its parent, for example, the "secondlevelcontrol" has the reference to "thirdlevelcontrol".With this level of nesting, I want to manage the asynchronous calls on every user control so, when the first level is loaded the javascript to load the second is loaded too. When the second level is loaded the javascript to load the third is loaded too.
To do asynchronous calls I'm implementing ICallbackEventHandler interface. As you can see in the examples, controls are added to the page as plain html. The method "ProcessOnLoadEvent" executes all lines of the "OnLoad" event of the user control.An example of the implementation is this for the user control of fourth level:
public string GetCallbackResult()
{
return _callbackRendering;
}
I have written a user control that captures some user input and has a Save button to save it to the DB. I use a repeater to render a number of these controls on the page - imagine a list of multiple choice questions with a Save button by each question.
I am loading the user control inside the repeater's ItemDataBound event like this (code simplified):
[code]....
The problem is that when the Save button is clicked, the page posts back, but lbnUpdate_Click is not called. The Page_Load event of the page itself is called however.
I should mention that the repeater is part of a user control, and that user control is loaded inside another user control (this is a DotNetNuke site which makes heavy use of user controls). The Save button link looks like this:
For a "dashboard" module I need to dynamically load user controls based on criteria as the user enters the page (role, etc). The problem is that the events are not being fired at all from the controls
As I understand it I need to load the controls in the OnPreInit method of the dashboard page, however I cannot get a reference to the Placeholder control at this point of initialization (i.e. I get a NullReferenceException); trying to load the Placeholder dynamically via Page.FindControl gives me, ironically, a StackOverflowException.
I've tried loading the controls in PreRender and OnInit as well but the events in the controls are not wired up properly and will not fire.
I have a tab control on my page and on click of tab user control is loaded dynamically.I need to load the javascript file of that user control dynamically. I don't want to add the reference of my js file on parent page.so in my .ascx page load event i added:
Part of a web application we have uses an in-house web control assembly. This assembly contains several web user controls where several of these are used by other web controls within the same assembly.
The assembly is built as a website with a web deployment project.
The main web application's pages are dynamically compiled through a service into a single assembly and placed into the appropriate bin folder. In our development server the old assemblies aren't always tidied up and removed, meaning the folder gets full of old assemblies.
When the page that uses the in-house web control assembly (mentioned above) runs, the asp.net instance throws an out of memory as it loads all the old assemblies in an attempt to determine which assembly houses the reference to the user control being used by the other user control inside the same assembly.
We've been using the following inside the top level user controls to register the other controls
Of course when the application runs this gives no information as to which assembly it can find it in.
Is there anyone that's come across this problem before? It's not really a problem as our live servers use a clean up tool to remove old assemblies, but there are still potential situations where we could get out of memory caused by this (for example the tool stops working!), so it would be nice to resolve this problem.
I got 15 tabs and 15 user controls assigned to each tab.All are loading at once which id delaying the process. I want to load one user control on selection of a tab in tab container.
and I on occasion want to add items to it using javascript/jquery.
When I select the items that have been added and it does a postback I get the following error:
Invalid postback or callback argument. Event validation is enabled using in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
I have a usercontrol that uses a callback to update itself. If I add the control to the aspx page everything works fine. However, when i add the control using Page.LoadControl and Control.Add on a Placeholder i get the following error: "The target 'ctl00$ContentPlaceHolder1$ctl00' for the callback could not be found or did not implement ICallbackEventHandler". I tryed assigning the ID of the control also which failed with the same error. I am using asp.net 2.0.
In my default.aspx page I have a PlaceHolder control within an UpdatePanel. In this placeholder control I will dynamically load a web user control, which is just a form with a submit button. On this user control, I have the form within an update panel and I have the "Submit" button's Click Event added to the triggers.
When I submit the form, the UpdatePanel on the web user control nor the update panel on the default.aspx page are capturing the post back, thus causing a full post back which refreshes my page.
how to capture this post so its rendered in Ajax and not a full post back?
I have a Gridview that I am using in a User Control. The grid loads great and my paging buttons that exist outside of the grid itself work properly. When I click my delete button inside the grid, I am getting an invalid postback message. How should I handle this? My control raises one event by the way.
I am trying to add dynamically a user control I created to an aspx page after it is loaded. I tried sending an ajax request to a handler that used RenderControl function and sent back the control's html. I appended it to the DOM using javascript.
The problem is that some of the controls must go through their Page_Load function and that doesn't happen when using RenderControl function.
I have created a web user control (MemberDetails.ascx) which is loaded dynamically on a page (Member.aspx) for my website. The control has some TextBoxes. I want to store the values inputted by a user in these TextBoxes to a database on the click event of a button that is on the Member.aspx page (i.e. not a part of user control).
I have created a user control that contains two asp calendar controls. I need to add this user control twice on the same asp page, let's say for Check in date and Check out date. Since the two are conflicting to each other when I add it twice statically, I now dynamically add them on button click so that each time only one control is loaded. The problem is, when I select a date on a calendar, it seems that the selection event is not happening at all. Of course, I am not getting any date.
protected void Page_Load(object sender, EventArgs e) { LoadMyControl(Parameters); //Do it every page load to preserve it's state } protected void LoadMyControl(string parameters) { plchld.Controls.Clear(); Control userControl = LoadControl("TheUserControl.ascx"); userControl.ID = "userControl1"; plchld.Controls.Add(userControl); }
Now inside this control, when a button is clicked I want to update ,let's say a Label on the hosting page. What is the best way to do it? Custom event?
I have a problem with ViewState. I have an aspx page that has a treeview on the left and an UpdatePanel with an ASP.NET Panel inside on the right. It is in that inner Panel where I load and unload dynamically user controls. I use that update panel to load dynamically controls.
I also made a custom control for my user controls because I need to pass some values from page. On that constructor I use ViewState to store these values.
The first time I load the user control I call its constructor with parameters. When I reload that user control on each postback I use its normal constructor.
My problem is I the values I've stored on ViewState has become null on successive postback.
Update:
This is a piece of my user control:
public class MyUserControl : System.Web.UI.UserControl { private int PKId { get { return ViewState["pkId"] as int; } set { ViewState["pkId"] = value; } } public MyUserControl(int pkId) { this.PKId = pkId; } ... }
I'm following this article to load controls dynamically: http://msdn.microsoft.com/en-us/magazine/cc748662.aspx#id0070065.
Second Update: I also set the same control ID when I load the user control at first time and on each reaload.
Maybe I can use another method to store these values like input hidden fields or Cache. I've choosen ViewState because I don't want to overload server with Session values for each user.
Third update:
I load the controls with this code:
System.Web.UI.UserControl baseControl = LoadControl(ucUrl) as System.Web.UI.UserControl; if (baseControl != null) { baseControl.ID = "DestinationUserControl"; PanelDestination.Controls.Add(baseControl); }
And reaload with this code:
DynamicControls.CreateDestination ud = this.LoadControl(TrackedUserControl) as DynamicControls.CreateDestination; if (ud != null) { ud.ID = "DestinationUserControl"; PanelDestination.Controls.Add(ud); }
I have user control that inherits a base control class and these user controls are loaded using the LoadControl method, I can't seem to figure out how to raise events from user controls to the page that are dynamically loaded this way. Here is the delegate and event in the base user control class.
public delegate void SomeChangeEventHandler(object sender , SomeChangeEventArgs e); public event SomeChangeEventHandler SomeChangeEvent; public virtual void OnSomeChanged(SomeChangeEventArgs e) { if (SomeChangeEvent != null) { SomeChangeEvent(this, e); } }
What i did.........Created User Control like One.ascx with one button
<%@ Control Language="C#" AutoEventWireup="false" CodeFile="one.ascx.cs" Inherits="one" %> <asp:Label ID="Label1" runat="server" Text="Hello, this is My First User Control dynamically loaded :)"> </asp:Label><asp:Button ID="btnShow" runat="server" Text="Show" OnClick="btnShow_Click" /> On Code behind public void btnShow_Click(object sender, EventArgs e) {
[Code] .....
Fail to redirect user to google.com by clicking button which written in .ascx file.
I have a aspx page, default.aspx, with an user control in it. Inside the user control (UC 1) there is a DataGrid. When the DataGrid is loading data with ItemDataBound, I need to dynamically load another user control (UC 2) for each row in the DataGrid. UC 2 has a Button ( BTN )with an eventhandler associated with it in code behind.
User control loading is fine, and the Button, BTN, is there. However, when I click the Button, the eventhandler is not reached, not firing, even though the page does postback. I googled for this issues, and I know the dynamically loaded user controls need to be loaded every time the page is postback. In my case, it needs to be loaded each time the datagrid is doing ItemDataBound. I did it and even hook up the eventhandler with button click event each time when the user control is dynamically loaded. I set EnableViewState to true on the Page and controls.
The following is part of the code from UC 1, AcctPaymentDetail is UC 2 in the code.
I have a blank user control (child) and during Page_Load i create some text boxes and a button. I also add an event to the button.
I then load that user control dynamically from a placeholder in another usercontrol (parent). Both controls are rendered correctly but when i click on the button, the event isnt fired. how to handle the event?
Child code:
[code].....
If i use the child control directy (ie without the parent the control) the click event is raised and handled nicely. But when i use the parent control, the debugger wont even hit a breakpoint inside UpdateButton_Click().
When user cliick on the control before page fully loaded it goes to error page.
Following is the trace.
Execution Error
Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
I have a user control that is dynamically added to a placeholder control inside an update panel in my main page. The user control has a linkbutton where I try to handle its Command event. The first time the link button is clicked after the user control loads, the form posts back but the command event handler does not execute, although the user control is still on the screen. The second and subsequent times the link button is clicked it works perfectly. When the user control first loads and I mouse over the link button, the browser status bar says: javascript: __doPostBack('ctl08$lbTest',''). After the first click, when I mouseover the link button the browser status bar shows javascript:__doPostBack('ctl07$lbTest',''). Why the changed in id, I can't figure but it must be why it is not hitting the event handler the first time it's clicked. Here is the cs code that loads the user control:
