AJAX :: Dynamically Create Controls / ASCX Via Callback
Apr 27, 2010
is anybody interesting in share and join to develop callback web controls. My purposes is lower unsynchronized page development cost. I have developed a base class and a set of common controls. Currently, they allowed to be loaded dynamically in a control or ASCX via callback event using sample server side code. Control library code will automatically register javascript and render it on client browser. These controls worked fine in both callback and postback. To load dynamically from an ASCX file.
'ascx1.ascx contain some callback-able controls
Private Function LoadAscx_DuringCallback(Optional ByVal RenderMe As Boolean = False) As String
Dim rt As String = ""
div1.Controls.Clear()
Dim c As Control = LoadControl("~/Test2/ASCX/ascx1.ascx")
c.ID = "ascx1"
div1.Controls.Add(c)
If RenderMe Then rt = CallbackManager1.RenderControlHelper(c)
Return rt
End Function
Or to load dynamically as a control
'c is a callback-able TextBox
Private Function LoadControl_DuringCallback(Optional ByVal RenderMe As Boolean = False) As String
Dim rt As String = ""
div1.Controls.Clear()
Dim c As New ACT360_CallbackControls.ZYH.TextBox
AddHandler c.KeyUp, AddressOf TextBox_KeyUp
AddHandler c.GetFocus, AddressOf TextBox_GetGocus
div1.Controls.Add(c)
If RenderMe Then rt = CallbackManager1.RenderControlHelper(c)
Return rt
End Function
I'm developing an ASP.NET application and I'm trying to do the following:
I'm going to have only one ASPX page splitted into two columns. On the left column is going to be a TreeView, and on the right column is going to be something to edit treeview's nodes.
When the user can select a treeview's node to edit on the right column. Depending on the node's depth fields on right column will vary.
I wondering to use ASCX controls and load on right column dinamically using AJAX, for example. Is there a better choice? Can I do that?
I don't want to reload the entire page when the user wants to edit a treeview's node. Maybe I'm going to need an UpdatePanel on the right column to load dinamically ASCX controls, isn't it?
I have an issue with gridview and ascx's inside. Into the item template I'm dynamically loading ascx files depending on the row hiddenfield value. Ascx control is then "opened" in panel with modalpopup extender. The issue is ascx control with ceratin programming logic behind does not postback in this scenario.
I have a dropdown list on my homepage which users select a category. After selecting the category, user will fill a form which has related controls to that category in it.
As I have many categories, I just want to have single ascx page and adding controls to it dynamically according to the user choice.
For example: One chose Telephone category, he will face a form having drop down lists asking, what brand? what color? And one chose, book category, he will face drop down lists asking which type? howmany pages?
So 1 ascx must do my work at runtime done as I have alot of categories.
I am going to take these criterias from a database table which has CategoryID and Criteria colomns.
And if I can do that, will it be possible to add field validators to these dynamically created controls.
I'm dynamically adding a calendar extender like so:
[Code]....
When a postback occurs I get the following error:
Extender control 'ceDateFrom' is not a registered extender control. Extender controls must be registered using RegisterExtenderControl() before calling RegisterScriptDescriptors(). Parameter name: extenderControl
apologies beforehand for what can possibly be a daft conceptual question. I have an ascx control that has a bunch of ASP labels and buttons in the ascx page and some other public methods and properties in the code behind. When I drop this ascx control in a page it all works fine. I now have a page with a placeholder and I am trying to dynamically create an instance of my ascx control and put it there. I then reference this control in code and while all public methods and properties are available (ie MyControl.TitleString = "Hello";MyControl.DoSomething();) none of the ASP controls are. Rather, they are all null. So MyControl.buttonSave is null, MyControl.LabelTitle is null, etc. Is this by design? Am I missing something? If not, what's the point of being able to create dynamically do this?
I'm developing an ASP.NET application with C# and Ajax.I have a page that holds user controls loaded dynamically. I need to pass some data (integer values and some strings) to the user control that has been loaded dynamically.Now I use Session to pass these values, but I think I can use another way; something like VIEWSTATE or hidden input.What do you recommend me?The fact that I load the controls dynamically is important because controls are loaded on every postback, and I can't store any value on controls.
Is is possible to build a form, accept parameters and from THAT construct a new .ascx page AND the code behind for that page? What I'm proposing is having some code snippets that just need parameters added and can then be used to create a web user control that can be added to existing pages. This .ascx file would be a real file after creation, not dynamic every time.
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.
i use cascading dropdown lists (in a user registration form) and when the user hits the submit button i get the error: "Invalid postback or callback argument" I've seen on the net that this is a problem dating back many years but still haven't found a solution to this. I've read about changing EnableEventValidation to false, but this poses a security risk.
Ive got some custom code that im using to load user controls dynamically depending on the option a user selects from a menu control on the page.
I wanted to create an admin page that can be used to provide a one stop shop to complete all actions within an app im building, (like a template/iframe scenario that loads all selections in a screen on the right)
My code works, however when the user has completed an action sucesfully within one ascx, then selects another from the menu on the left, it wont load the new control, it comes up blank like it hasnt refreshed properly meaning that they have to close down the page and reopen it. (which is very annoying)
My codes below, can someone take a look and see if they can see whats wrong.
I am not able to get the htmlinputimage control id created dynamically based on no of rows reterived from db.
these controls are bn created in usercontrol (.ascx.vb) page
The actually requirement is ...there are set of images in a table, i need to get a particular image src, based on that i need to collect the image id(s) and use it for futher process...
and this is poosible using a FindControl... which i have bn trying , but all invain...
I am using ASP.Net 3.5 with AJAX. I have a situation where I create a table dynamically depending on user input. One column of the table will contain a small image. Right now, it takes a click of the image to show a larger view in a new window. I would like to change it so that when the mouse moves over the image a HoverMenu pops up with the enlarged image view. I have done this with image controls placed on the page at design time where only the image's url is dynamic. How can this be done if image conrtol is created dynamically in the back-end code?
I'm trying to create a calendar extender dynamically on my application. For that i am using the following code:
[Code]....
THe problem is that i'm having a runtime exception, on the OnPreRender of the ExtenderControlBase.cs saying that "A control with ID "filtrodatainicio" could not be found. I'm pretty sure the problem resides in the fact that i'm creating both the text box and the extender dynamically but i can't quite figure out what should i change to make this work.
How would I create an AJAX Accordion pane from the code behind? I would like the user to be able to click a button to add a new pane to an existing accordion control. However, I can only seem to create one new pane because clicking the button after that causes the old pane to be overwritten. I have this in the button click event:
[Code]....
A new pane is created with the correct content, but then it keeps getting overwritten. I've looked around and have seen similar problems but no answer.
I have .ascx web user control in my web site. Now I want to make dll for that .ascx file. let me know steps how can I make .dll file for that .ascx web user control.
Whenever a postback would occur (AJAX'ed by an UpdatePanel) I want to do a callback beforehand and only after the callback has completed (either successfully or not) should the postback occur. How can I do this?
Elaborate explanation: We use ASP.NET AJAX (UpdatePanel 'n stuff) together with DevExpress controls. Among those controls is the ubiquitous GridView. As is typical with ASP.NET gridviews, you can edit rows one-by-one, and to save your changes you have to hit the "update" button at the end of the row. However if you make some changes to the row, then forget to press the "update" button, and hit something else in the page (say the big red SAVE button that causes a postback and saves the whole form to the DB), your changes will be lost. The row will still be in edit mode, but it will have reset to the data it had initially when you started the edit.
Our clients are not happy with this and want the row to be saved automatically if the user forgets to do so himself. Luckily the DevExpress gridview is smart enough to have an "Update()" method which I can call from JavaScript. Unluckily that causes a callback and returns immediately. If I allow the postback to continue as normally, the callback will get aborted. Well, technically it's a race condition I guess, but so far it seems that the postback wins. There are events to which I could attach for success/failure of the callback, but I don't know how to "resume" the postback that started it all. We could turn off callbacks for all the grids, but that would be a performance disaster.
I have an accordian control with a set number of panes. Each pane has a table created with the code:
[Code]....
I would like to display information about the room occupants when the user hovers over the label. Is the HME the right tool for this? If so, how do I add it?
