Web Forms :: Getting State Of Dynamically Added Control?
Feb 8, 2010I dymamically add checkBoxList to the page. How can I get checked items from it without adding it again?
View 7 RepliesI dymamically add checkBoxList to the page. How can I get checked items from it without adding it again?
View 7 RepliesI 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.
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I am writing a search results page for an airline booking system. I have Next/Previous buttons to view flights for the next or previous days. The way i have done my results grid is that i use an HtmlTable and dynamically add rows, cells and controls into the cells. This gives ultimate flexibility given that we can add any control type we want and have it function as it does everywhere else in the system. As you should be aware - i must recreate these controls each time the page is reloaded (in the page_init event) since asp does not handle this automatically.
When they go next/previous it refreshes the flight data and re-populates the grids. If they select a flight in the return grid (by checking the RadioButton), and go next on the FIRST leg grid, the selection of the return leg stays the same after the postback
- which is great. But the problem is, if the flight they selected on the return leg is no longer available it will not create the control and i get the following error;
"Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerServerErrorException: Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request."
Is there any way to tell asp.net that if you do not find the control anymore, simply ignore it rather than throwing the error? The nature of this design is that there potentioally WILL be a different layout after the page is posted back.
Can a placeholder control be created dynamically such that you can add controls to it later on?
PlaceHolder ph_grid = new PlaceHolder();
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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.
While I am using a "Telerik" control here it shouldn't be any different I guess;
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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...
How can I get the placement of dynamically added control in any page event.
View 6 RepliesI 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.
View 14 Repliesi have one html table "table "and added controls it at run time as :
HtmlTableRow tabelrow = new HtmlTableRow();
HtmlTableCell tablecell = new HtmlTableCell();
Label lbl = new Label();
tablecell.Controls.Add(lbl);
then i want to get each controls by using foreach
such as (foreach control c in table.controls) or (foreach control c in tablecell.controls)but its not working.
How can I add the dynamically added control to validation?
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the client-side validations kicks-in. Is there a way to explicitly include the deferredly-created inputs to validations?
I've got a custom ASP.Net web user control I've built; done this enough times before but this one is misbehaving and I can't spot why.
Where the calling page includes the user control directly in its markup, all is well and the control behaves as expected.
However if the page adds this particular control dynamically (to a placeholder in the master page, which is what's calling this whole thing) the elements within it stay firmly NULL - nothing from the user control gets written to the client at all, including static content within the user control.
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.
Here's my code:
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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.
View 2 RepliesI 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
I have a GridView of thumbnail photos within an UpdatePanel, with clickable icons in each row which each load a User Control containing a small Google Map into the relevant row. The idea is that the user can geotag (by clicking on the map) any photo in the GridView.
In the map User Control, there is some Javascript initialising the map:
function initializeMap() {
if (GBrowserIsCompatible()) {
var map = new GMap2(document.getElementById('Map'), {size: new
GSize(336, 200)});
// set the map controls, set the centre, etc.
}
}
Problem is: I don't know how to call the initializeMap() method. Because it's dynamically added to the page, any attempt to link it to the calling button by "onClientClick=initializeMap()" for example, gives a JS error, saying the method isn't defined.
I've tried
ClientScript.RegisterStartupScript(this.GetType(), "initializeMap", "<script type="text/javascript">alert('Here'); initializeMap();</script>");
but I don't think I'm on the right track with that one either.
I have an asp page "A" and I've created a user control "B"
When I do A.Controls.Add(B), I would like to make an element, say a TableRow which is defined inside control "B", invisible via code behind.
When looking through Controls of "A", I cannot seem to find that table row.
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 composite user control consisting of three standard table cells (a legend, an image with a tool tip, and a text field control). If I add these to a TableRow in my aspx page it works fine and produces legal HTML in my source. The below works fine ...
<tr><MyControl:dataField
ID="txtEmail"
DataType="Email"
runat="server"
/></tr>
However when I try to do the same programmatically (C#) the TableRow won't accept anything in its Controls collection that isn't a TableCell. I could make my control a nested table in its own right but I lose the alignment of my form items on the page with multiple controls, as each table aligns itself according to its contents. Is there anyway I can make the TableRow accept my control as collection of cells or do I need to do some casting or making my user control inherit some kind of TableCell attributes? I can also dynamically add my controls to a TableCell item which actually displays OK in IE but creates illegal HTML (<td><td></td><td> ... </td></td> - I assume this is illegal) in my resulting source. The code below DOES NOT work ...
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i'm trying to do a simple wallpost function like facebook. I hv a link to show older post too. when i click on the link, i would like to dynamically retrieve another 15 record from database and add it. Currently i'm trying to bind the data onto a dynamic repeater and add it in a placeholder. but it will disappear after postback.i tried to dollow sample here, but i'm adding a more complicated control which is reapeter , so i'm stuck.http://www.asp.net/ajax/videos/how-to-dynamically-add-controls-to-a-web-page and another issue. if i click the button again, it will show the next 15 old record again, but i dont want to rebind the repeater coz then it's a waste of resources and also it will make any text that was entered in the comment textbox (which is not submited yet) to lost.
View 4 Repliesi want load a usercontrol dynamically and pass a string to it ho do i do it..
View 3 RepliesI've been struggling with this for several hours now so I thought I'd give this forum a try. The problem is that I'm adding two kind of buttons (editBtn and delBtn) which show up fine but they won't fire their respective method when clicked. I also have a third button which works just fine.
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How to get a postback on a button added dynamically
View 3 RepliesI am making a website where the user has to choose some addresses form a list of street names.
I have made a usercontrol Witch I dynamically adds to the website depending on some choices the user makes (Zip, and Streed name) The usercontrol contains a checkbox. When the user clicks a button on the site I would like to find all the usercontrols the user have checked.
The usercontrols is contained in a asp:Panel
I have tried with a foreach loop where I loop all the controls in the panel. It only retun one control.
Then I have tried with at ControlCollection ctrlCol = ContentPanel.Controls;
It only returns a LiteralControl. Then I have tried to loop all the controls on the webpage testing for the type as the usercontrol but no luck
How can I find an loop thru all my usercontrols and find the checked?
Ihave the following code and would like to be able to control the layout of the textboxes and labels so they arent just in a long column. Right now everything works and controls are added, but they are added in 1 column which if you chose 32 from the dropdown the page becomes very long.. so would like to maybe wrap them across 3 columns so that each has at least 10 per column.
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In My page i have a ajax Combolist Box in which if i select any no it generates some controls
here is my code
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Now i want to retrieve all the values Entered By the user in the textBox on btnSubmit_Click