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Load User Controls dynamically based on other control events

I have a "cross section" of variables that I need to use to generate a set of user controls dynamically. In the center of the page I have a Telerik multitab/page. I have a custom tree menu and a custom menubar, based on the combination of menu input each of the tabs should load a user control relevant to that cross section of data.
For clarity, almost each tab, treeview, menubar combination needs a unique control.
My problem is that all the postback/loading happens well before the "OnMenuChanged" event triggers, so I'm one "set" of user controls behind. Even if I were to use session/viewstate they wouldn't get assigned until after I needed the value stored in them.
Currently what is happening is the default user controls are loaded in the "pageviewcreated" event, then in the onMenuItemChanged I go back and reload the user controls. It seems very inefficient and is complicating up the approach for selecting the right .ascx.
How do I manage this?

If I understand what you're trying to do could you not use a placeholder control and inject your needed usercontrol into that inside of the events you're managing? Try doing something like this inside of the "OnMenuSelected" event.
WebUserControl1 uc = (WebUserControl1) Page.LoadControl("WebUserControl1.ascx");
PlaceHolder1.Controls.Add(uc);

Reordering the position of usercontrols on a ASP.NET page

I am working on a page that has user controls that are arranged in a particular layout. I am modifying that page to support reordering the position based on user's preferences. So, essentially, on load, I have information on where I need to position the different user controls.
I can think of 2 approaches:
Do the reordering on the client side. This is not ideal for the user
as they see the reordering happening.
Do the reordering on the server side. This requires me to do a lot of
rewrite to dynamically load the user controls based on preferences.
Are there any other ways of accomplishing what I am trying to do?

I would recommend rearranging on the client-side because
You will save a post-back.
You will make the website seamless.
How can do you that
Use a main div containing all controls and another containing a loading image. Toggle there visibility while rearranging the controls using javascript, or
You can set visibility:hidden to your body and then after rearranging set visibility:visible
The drawback of this approach is that you will have to use absolute positioning.

There is an easier way; rendering is controlled by the parent container rendering them. It is possible to create a container, and have full control over the ordering of the rendering of its children (by overriding the RenderChildren method). It's not the easiest option, but it can work. The steps are:
Create a class that inherits from ContainerControl
Override the RenderChildren method
Within this method, it would render the children in the container, override it, do not call the base class version of it, and get the instances to the controls and render them. This is where the complication arises because you have to.

ASP.NET changing controls order in div

I have two controls in div wrapped into update panel. My code requires for user to be able to change position of second control left,top,right,bottom from first controls point of view. I was thinking of adding a MultiView and adding 4 Views but controls can't have same ID in views and that is essential for my code functionality.
What would be best approach here?

You could add the second control into a placeholder control. See this question : How can you move ASP.Net controls to different places on the Web form at runtime?

How do I add events to nested server controls? (ASP.Net)

I am building a custom master page type control i.e. sort of like a datagrid but should be easier to add custom functionality into it. It's going great but part of the desired functionality is to have a paging control that switches on and off and part of that control would be a textbox that displays the current page number and on TextChanged redirects to the new page of the dataset.
The problem I'm having is that technically the textbox which has its event fired is embedded in a control that is embedded in the control you actually put on the page sort of like
Page
|
Display Control
|
Paging Control
|
Textbox
Buried all the way down there the event is not firing. Worse the postback javascript isn't even being written onto the page (Nothing on the page posts back so far this is the only bit that really needs to).
I've been trawling around Google for quite a while now and picked up that I need to implement INamingContainer (done) and I need to add the control into the page's control tree (is Pre_Init too late for that? When's a good time to Add the Control to the page?) then the event should fire, apparently. But I've been unable to find an example of best practice on this there are quite a few near misses where people are having button angst but this isn't a button.
So can anyone point me in the direction of getting a control embedded in a control embedded in a control added to a page to behave properly?

You need INamingContainer only if you plan to add more than one instance of your custom control to the same page. What it does is enabling unique id generation so you don't end up with controls with the same ID. I recommend you inherit from CompositeControl when creating your custom control.
Pre_Init is not too late. Actually it is pretty early considering the lifecycle. You can instantiate custom controls and add them to the live controls collection in a lot of places. I would recommend you do it in Page_Init (before viewstate is loaded) or Page_Load(after view state is loaded). Even if you add it later in the page lifecycle the control will catch up in events.
To subscribe to events of child controls you can use the FindControl method:
MyControl myControl = Page.FindControl("MyControl1");
TextBox textBox = myControl.FindControl("TextBox1") as TextBox;

The answer was a combination of the above answer and the comment on the original question. The vital thing to get the event to happen is to make sure that your controls (parent and child) inherit from CompositeControl and INamingContainer e.g.
public partial myControl:CompositeControl,INamingContainer
etc...
Then you override your composite control's CreateChildControls() method and create your controls and do the wire up there. This will ensure correct bubbling. and mean that the event handling takes place within your comoposite control...

accessing data from a dynamically added custom control

I am writing a survey generating system in asp.net. i asked an ealier question about the best way to create controls that can be passed about as variables. This was problematic with user controls so i was advised to use custom controls and a quick way to do this was to inherit from the panel control and just add a bunch of standard controls the the controls collection by overriding the CreateChildControls method. This way i could create my "survey" controls,which are basically Questions in the survey. THe question controls are then dynamically added to the page. This all works well but know i have come to the point that i want to try and retrieve the values from these controls and i seem to be lost in a nether world of of viewstates and page lifecycles. I can ensure that the dynamically added text boxes have a known ID, however even if i add the parent control in the page init handler the CreateChildControls method does not run until after until after the viewstate is loaded. I cannot work out how to retreive the values from these text boxes.

You can call the EnsureChildControls method on the init handler of your control to ensure CreateChildControls is called before the ViewState is loaded.

You certainly seem to be doing this the hard way. TextBox values are not saved in the Viewstate, they are posted in the request.
Why aren't you using a UserControl here? So you can "pass" it somewhere? what exactly are you trying to do?