Web Forms :: Event Not Firing On Dynamically Added Control
Feb 23, 2011
While I am using a "Telerik" control here it shouldn't be any different I guess;
[code]....
What happens is that the control is created and rendered;
When I change value in the Combo box a Post-Back happens.
HOWEVER, the event RadComboBoxSelectedIndexChanged does not fire. Also when I am back at the page the new value is not saved; Obviously, i recreate the control every time. If I don't I get a ViewState error. Seems to me that there some ViewState management problem, but I cannot identify it...
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'm creating an ASP.NET control dynamically based on a value selected in a dropdown; for instance the field can be a textbox or a checkbox (for now), and then it gets added to a placeholder control. However, I'm unsure how to retrieve the value - using the placeholder's FindControl method returns null although I'm specifying the ID when I create the control.
I have a user control say SearchVendor.ascx which contains 4 buttons a gridview and another user control. I need to load the control dynamically actually as a modal pop up
I get this code
var uc = Page.LoadControl("~/blah/VendorProductSearch.ascx") as VPSearch; uc.ShowVPSearch(true); _tempPlaceHolder.Controls.Add(uc);
it works fine the control gets loaded properly but onclick of any button the second time the control disappears ?
I want the dynamically added control to remain until the user clicks on the cancel button
im creating a button control in page int and im assing a click event for the button control. here the click event is not firing for the first time. here is my code.
I have a control that handles commenting. In this control, I have set a delegate event handler for sending an email.
I then have various types of controls, e.g. blog, articles etc, each of which may or may not have the commenting control added (which is done dynamically with me not knowing the id's), i.e. the commenting control is added outside this control. Each of these controls handles it's emailing differently(hence the event).
What I'm trying to determine, is how to assign the event in the parent control. At the moment, I'm having to recursively search through all the controls on the page until I find the comment control, and set it that way. Example below explains:
COMMENTING CONTROL
public delegate void Commenting_OnSendEmail(); public partial class Commenting : UserControl { public Commenting_OnSendEmail OnComment_SendEmail(); private void Page_Load(object sender, EventArgs e) { if(OnComment_SendEmail != null) { OnComment_SendEmail(); } } }
PARENT CONTROL
public partial class Blog : UserControl { private void Page_Load(object sender, EventArgs e) { Commenting comControl = (Commenting)this.FindControl<Commenting>(this); if(comControl != null) { comCtrol.OnComment_SendEmail += new Commenting_OnSendMail(Blog_Comment_OnSendEmail); } } }
EDIT:
The reason I ask is that if I search from this.Page as the initial control, I am worried about time taken to search down the control tree to find it. Each different type of page would be different in how many control it would have. On some testing, it returns back quite quickly the result.
I have a gridview that on it's RowDataBound event I dynamically add Image Controls to some columns.
The problem is that I lose these images on the next PostBack.
OBS: The GridView's EnableViewState propertie is already set to true
I know about the page lifecycle, but how can I persist these images if I have to add them on the RowDataBound event?
In addittion, if I add a static TemplateColumn with an Image Control and I set it's ImageUrl propertie inside the RowDataBound event it will obviously persist between postbacks. The problem is that I don't know how many columns with images I'll have, it's defined on the datasource.
The scenerio is I have a UserControl. This user control will create dynamically ListBoxes if the given List's count > 0. The controls are adding dynamically, there is no problem with adding them, but the event handler is not adding. If I select an item in first listBox, the secondListBox will be added dynamically, and items will add dynamically too. First listBox appears, but the selectedIndexChanged event handler doesn't work. What can be the problem with my code?
I´m using a Repeater to generate Items out of a Database. Each ReapeaterItem should include an UpdatePanel, because i have to Update the Controls inside the UpdatePanel and do not want to reload the complete page. Inside these dynamically generated UpdatePanels (each RepeaterItem has one) i´m adding up to three Checkboxes dynamically (based on the Database). These Checkboxes need to fire the "CheckedChanged" event, because on some conditions i want to enable/disable/check/uncheck Checkbox1, 2 or 3 based on business logic. ... Hope you got this so far. I´m adding all Controls and have the EventHandler Added. But the generated Code does not reflect the Event Handler. I tried OnItemDataBound, OnItemCreated, PreRender, ... Events to add the Eventhandler too, but i was not able to find the CheckBox-Control with the ID.
I´m totally lost with this and on the way to use Buttons instead of Checkboxes. From what i read so far is that with Buttons i can use the CommandName from the Button and the ItemCommand-Event from the Repeater to get a workaround, but then i need to reflect the "Check" on the Page in some way. btw, every Repeater (8) sits inside an ajaxtoolkit-accordion control. Here i give you some Code:
I have a accordion control inside an update panel. As I loop through the Products table and the Details table in the code behind, I'm creating the accordion panes that will display the data. There's an "Add to Cart" button created for each product (each accordion pane), and I'm asigning an EventHandler for that button, but it never fires... Here's the code where I'm creating and adding the button to the page:
[Code]....
[Code]....
[Code]....
And here is the code event that is suposed to fire:Private Sub addToCart(ByVal sender As Object, ByVal e As CommandEventArgs)
I'm trying to create a button dynamically with event by original button. The original button's click event response creates a button. The new button has a click event attached with a test message.What I have to do is onclick change background color of dynamically created button and grab id value to delete when button delete is clicked. Unfortunately, when I click the dynamically attached button, nothing happens.
Am adding a sample webpart dynamically in which i add a Button Control.the isssue is Event is getting fired when i Click on the scond time and the other issue is the web parts are getting duplicated for each postback.
I am adding numerical page links for paging of a repeater. I have used on of the numerical paging samples as my base. It works fine if I have less pages than my maximum total links. Eg if I have 11 pages, but only showing page 1-10 plus a next for the 11th, I get an error about duplicate control ids. I changed my control id to use a Guid in the string to keep it unque, after making this change the event handler never fires
private LinkButton createButton(string title, int index) LinkButton lnk = new LinkButton(); //lnk.ID = System.Guid.NewGuid().ToString("N") + "_" + index.ToString();//Event does not fire if I set ID with Guid [code]...
I am creating two buttons within the StoryGet() method, first when the page loads. When one of the buttons is pushed, lets say the left one - I want to call another method - "ButtonLeft_Click"
Ive used this same solution in other sites and it worked. With this solution, click event never fires.
If I move the StoryGet() call from Page_Load to PageInit() the button event fires, but because this event also calls StoryGet() the method runs twice, which I don't want.
I tried adding this to page_init so the original StoryGet() method only gets run the first time the page loads unless the method is called directly but then the page loads, but the button click event doesn't run again
if (!this.IsPostBack) { piccount = 0; StoryGet(); }
Their is placeholder inside update panel to which i add my dynamicaly created a div which contain a link button (dynamically created). When i click link button div get disappear and link click event is not fired
I have a gridview called gvResults. In the gvResults_RowEditing event I add a row below the one selected. In that new row, which spans all columns, I insert a user-control. There are two buttons and some textboxes in the user control.
My problem is that when I click one of the user-control buttons it never gets to the button event handler, I think because the user control is not recreated on the page postback. How can I have the user-control events fire before the parent page events fire?
I tried using an update panel, but I still get the parent posting back before the user-control events.
I am facing one strange problem,I have a gridview in which the last two columns have checkboxes and on those checkboxes click event I am doing some database operations.I also have one checkbox that is outside the gridview which actually shows or hides some of the gidview columns.This was all working well but now I have shifted that grid to a user control because I have to use it in two pages.The problem now is,When the page first loads and I click the check box or any control in the page that is outside the grid then it works perfectly.But once I click any of the check box within grid view column then its behavior chages, now even if I click the checkbox that is outside the grid then also the checkbox_CheckedChanged event of the checkbox that is whithin gridview is fired.That checkbox event then behaves something like a page_load event that is called for every page load and for every event with in the page after it is called once.
I know that if I re-add the control during Page_Load, the posted values will be repopulated when the page is rendered; however, this is not the case when re-adding the control during the Click event and I need to add the control during an event handler.
I am having datagridview control with dynamically added BoundField columns.I want to have tetxboxes in each cell of the gridview so taht user will enter data in gridview textboxes and at last on button click it will be saved in database.
