Web Forms :: How To Dynamically Add Web User Control
Jul 27, 2010
I have one label and table control in my webusercontrol.In my web form i want to add my webusercontrol dynamically and also i want to update value of label and table in my webusercontrol. I have tried using LoadControl method. The problem I am facing is that in my webform I am able to see webusercontrol but I am not able to update values.
I am trying to use my user control on my page which should load with data from a datatable. When the PageLoad event fires up I got the following message:
Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
[Code]....
here is the page code which cause the error message:
I want to know how can we create web user control dynamically.
Scenario: Basically i am developing registration user control. I have a web page(say, SelectInputs.aspx) that lists different types of fields along with checkbox attached to each of them for selection. Once i select desired input controls (which should appear in user control) and click submit button then the file (.ascx) should be created from code behind.
eg: Lets say on SelectInputs.aspx i select fields viz. Firstname(textbox), Lastname(textbox), DateOfBirth(3 dropdowns) etc and click on submit button then from code behind the .ascx file should be generated that will include Firstname(textbox), Lastname(textbox), DateOfBirth(3 dropdowns) etc.
how to load user control dynamically on asp.net page? I am loading user control in my page_Init() event under if(!IsPostBack) but when user post the with any button click then my user control is disapper?
If i am loading control without if(!IsPostBAck) then its fine, but each time a page is posted loading of control is not good because it will slow my web site?
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.
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 have a dynamically created address user control (on a customer administration screen) that is created through the use of a place holder. A customer can have multiple addresses, so they dynamically dropped onto the page.
I have got this far, but now I need to be able to save the updated addresses for the customer but I can't get any event to fire on the user controls. When I check to see run plhAddress.HasControls() it returns false?
The way I am generating the user controls is as follows.. private UserControl LoadControl(string UserControlPath, params object[] constructorParameters)
I am using 5 ,6 user control. I wanted to load diffrent user control on Click of menu bar. Means when I click on first link of Menubar 1 user control should load and 2 loaded when i Click on 2 link of menu bar. How to do that?
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 binded user control in gridview dynamically using templatefield (through code behind)
User control consists of 2 textboxes and one dropdown.
There is one button outside the gridview on the form. On click of that button i have to save the values of usercontrol's (child controls i.e textbox and dropdown values) but i am not able to get the values of user controls.
I am able to get User Control using LoadControl and child controls using FindControl but not able get values i am getting textbox values as blank and dropdown value as 0th selected index even though there is value entered by the user.
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:
I want to create a user control that will again contain a user control that will be dynamically generated and can be repeated N times with respect to data present in data table.
Im working with asp.net web application,I need to get multiple gridviews dynamically based on the count (which i get from database) for that i took a web user control and i added a gridview there . iwant to load that usercontrol in aspx.cs based on the count..
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:
I'm trying to make web form with two placeholders. Firs holder contains user control witch has list of buttons, each button opens different user control to second placeholder.
I get it to show user control in second placeholder but i can't get dynamically created user controls to fire events.
So how i can dynamically create working user control with button click?
Here is how i create those controls:
[Code]....
"field" is hidden field containing filename of user control to be created.
I have this GridView that have it's DataSource as a list of previously selected products. For every item on it, I need to Eval it's ID and load a specifc form that the user must fill, then after that i've got to update the GridView.
I have made those specific forms as User Controls, is this the best approach for this scenario?
If yes, how can I dynamically load them, in a way that I can make queries/postbacks then update back my gridview?
I have a page that contains radioButtons. Each click on a radio button loads a user control (.ascx) in the page.
What I am doing is loading all controls at the same time, but set their visibility to false. When a user clicks a radiobutton I set the visibility of the specific user control to true.
As a result I am loading all the user controls on each postback.
Im trying to create a "user control menu" where links to a page's usercontrols are placed at the top of the page. This will allow me to put several usercontrols on a page and allow the user to jump to that section of the page without scrolling so much. In order to do this, I put each usercontrol in a folder (usercontrols) and gave each control a Description property (<%@ Control Language="C#" Description = "Vehicles" .... %>).
My question is how can I access this description dynamically? I want to use this description as the link in my menu. So far, I have a foreach on my page that looks in the ControlCollection for a control that is of the ASP.usercontrols type. If it is I would assume that I could access its attributes and grab that description property. How can I do this? (Im also open to a better way to achieve my "user control menu", but maybe thats another question.) Should I use ((System.Web.UI.UserControl)mydynamiccontrol).Attributes.Keys?
This JQuery datatable is present in one of my webuser control named "LeftVerticalLayOut.ascx". I am dynamically instantiating Webusercontrol on click of a link button. This link button is bound with the trigger event of Update Panel control.
So clarifying once again : I have one UpdatePanel which I am triggering with Link button("lnkLoadControl") . On click on "lnkLoadControl" I am able to load Usercontrol("LeftVerticalLayOut.ascx") onto the updatepanel. Now the jquery datatable I am creating in load event of Usercontrol is getting generated.
After the datatable(having id as "example") is created, I am calling the below code in my
function loadHandler() { Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(BeginRequestHandler); Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler); }
[code]...
Now as I am creating the UserControl on the fly, the Jquery in not getting applied.
Is it possible to dynamically (and generically) clear the state of all of a user control's child controls? (e.g., all of its TextBoxes, DropDrownLists, RadioButtons, DataGrids, Repeaters, etc -- basically anything that has ViewState)
I'm trying to avoid doing something like this:
foreach (Control c in myUserControl.Controls) { if (c is TextBox) { TextBox tb = (TextBox)c;
[Code]....
...but obviously that doesn't exist. Is there any easy way to accomplish this dynamically/generically?