Web Forms :: Referencing Dynamically Generated Controls?
Jul 9, 2010
I'm displaying a table based on query results, and each record has a dynamically generated dropdownlist and submit button (and other controls, but this is simplified). That part works fine, but how do I reference the controls in a function? Here is the code I've tried. Create the controls:
[Code]....
Reference the control values (hopefully):
[Code]....
The function SubmitAction_Click fires when I click the Post button, so that part works. I just can't figure out how to reference the selected value of the dropdownlist. You can see that I'm explicitly giving the DDL a unique ID (DS_RecordID). I'm guessing I have to use FindControl to reference it, but I don't know how to format the code.
I have a grid and on each row of grid i generate a radiobuttonlist with 2 items dynamically in rowdatabound. On the save button event i want to access the data of the row and save the data in DB with which ever radio button is selected.I tried different things but all in vain. I tried to use hidden field so that whenever any radio button is selected in a row then in javascript i will update the hidden field but user can select multiple rows so this is not a good solution.
Here is my code of dynamic radio button list generation in rowdatabound event.
I'm trying to check dynamically generated "checkbox" value inside Listview.
I can reference non-dynamic checkboxes exact in same location (index) inside Listview using "e.Item.FindControl", however I can't reference dynamic checkboxes.
I have a gridview each line has 4 linkbuttons - Edit , Update , Cancel , Delete and a few columns with data...For example TeamName and TeamEmail, and a hidden column that contains a validator (for ease of validating controls that are found on the same row , same naming container)
When Edit button is Clicked , the specific line goes into editing mode , Texboxes are created for TeamName and for TeamEmail .
I create dinamically (code behind ) a new textbox that reads the value from the TeamEmail textbox , i give it a new id (let's say "Email") , add that email to the controltovalidate property of my validator , and call the validate() method of the validator.
Everything works fine when i modify the value in a worng format , the validator err message appears , when i modify the TeamEmail value to a good email format , the validator property isvalid becomes true , and the update is running , but my textbox is empty :( updating the TeamEmail value to null.
This is some bad code but hope you understand what i meant :
i hav a dyanmically generated gridview with autogenerated columns = true.. i want to change the width of a column of a grid... i tried to do it in row databound event as...
e.Row.Cells[1].Width = Unit.Pixel(300);
but it doesnt work... and since d columns are genrated dynamically i cant set d width as grd.columns[0].width =...
I am stuck in chart controls...Here is my prob... There is a ListBox containing some items...when user selects multiple items from the list box I want to generate a dynamic table with the number of columns same as that of the number items selected in the listbox. And for each selected item I want to show a seperate chart in the columns...Currently I want the same chart control for every selected item (i.e. a static hard coded chart that i will replace later by dynamic values)....I am using a method that draws a chart control using a sample dataset... I am calling it each time when a new column is created..Also the DrawChart method executes for the first column only and throws an index out of range exception! after the first execution...my code is not working...here
Let's say I have a booking form which is divided into 3 separate views in a multi view.
View 1: "How many people do you want to book for?" And then just a text box
View 2: "Please enter the details for each of the people" And then a series of dynamically generated text boxes - the number of boxes is determined by the value in the textbox in view 1 (e.g. if the users enters "3" into the text box, there will be 3 series of text boxes like "Details of person 1: First Name <textbox> Last Name <textbox>, Details of person 2: First Name<textbox etc..."
View 3: "Please review and confirm the details are correct:" Displays data entered in view 2.
Here's the difficult part - In order to generate the controls in view 2, I need to know the value of the text box in view 1. This value isn't available during Page_Init as viewstate has not yet been written. But - need to build the controls during Page_Innit. So - I thought why not try to grab the value of the textbox using Request.Form[Texbox1.ClientID]; - this is fine when moving from view1 to view2 but remember - I need to recreate these controls again if the user moves back to view1 or forward to view3 (it is a requirement that the user can move backwards and forwards between the views).
So - User enters value in Textbox in View1, hits the "Next button", we request that value using Request.Form and generate a series of controls dynamically. Then the user clicks "Next" again and moves to view 3 where we would like to show a summary of what they entered. But - we cant because those controls dont exist as we could not create them because the value of textbox1 is not available during Page_Init and we can't use Request.Form as the textbox isn't now part of request.form because we came from view2, not view1.
I can't figure out how to dynamically create these controls and then recreate them during page_innit on each postback so we retain any values the user might have entered.
i use the below code to dynamically generate two dropdowns and a text box in my MVC project.countValidate is used to concatenate and produce controls with postfix 1 ,2,3 etc.now i need to access the Criteria? series dropdown and check their values and according to the values received on changing the Criteria dropdown the value textbox must be disabled or enabled, in javascript.
I have a page with a ScriptManager, a generic HTML drop-down list (<select>), and an UpdatePanel. The UpdatePanel contains a PlaceHolder (for now). During Page_Load, a number of user controls are added to the PlaceHolder (really, it's several instances of the same user control). The number to add is not known until the page loads, so they do need to be loaded dynamically. The drop-down list is populated with the same number of menu items, and there is javascript on the page also (using jQuery) to show only one of the controls at a time depending on the state of the drop-down list.
Each user control has two buttons that should generate an asynchronous postback, a drop-down list that should generate an asynchronous postback on a change in selected value, and a button that should generate a synchronous postback. If I was not generating the controls dynamically, and if there was only one control, the structure would be something like:
[code]....
Of course, all the controls inside the ContentTemplate would actually be part of each user control.
Adding the triggers on the server side does not seem to work because no ControlID seems to the UpdatePanel find the relevant controls. I can use either the control's ID or the control's UniqueID, and it does not work, and I get an error along the lines of
A control with ID 'ctl00$ContentPlaceHolder1$ctl01$asyncButton1' could not be found for the trigger in UpdatePanel 'myUpdatePanel'.
So, I wonder if I need to register the triggers in the client instead using ASP.NET Ajax. I found this page that basically explains how. However, I do not know how to get the EventName taken into consideration. The examples I have seen so far have merely been adding button clicks, but I don't know how to handle the SelectedIndexChanged event from the DropDownList.
Are there examples out there I have missed? It doesn't , of course, that the method in the link I gave appears to be "unofficial," so I don't see any MSDN documents on the subject.
I am generating barcode image dynamically on button click .
The image is display on the asp image control, now I want to save that image in database
string barCode = txt_ID.Text; using (Bitmap bitMap = new Bitmap(barCode.Length * 40, 80)) { using (Graphics graphics = Graphics.FromImage(bitMap)) { Font oFont = new Font("IDAutomationHC39M", 16); PointF point = new PointF(2f, 2f);
I create a gridview dynamically to fit the contents of a datatable...This form will have other dataatbles thrown at it but for the moment I am only working on one to work out the details of the process.I will post all my code below...the problem is this. The code successfully geenrates the gridview the way I want however...whenever I select a row all the cells including the header cells dissapears [code]...
I have a table witch i programmatically fill with(multiple) IDs in the first column, options in the second and checkboxes in the third. The table is in a View as it is part of a wizard and is filled on view_Activate.
How can i get the checked property of the checkboxes when i pass to the next view? When i try to do that on view_Deactivate the table is already 0 rows...
I know i can use i checkboxlist(... whose properties i can get on view_Deactivate) but i'd rather use a table as it is easier to layout as i want it(header, columns, alignment,...).
I have a dropdownlist on my page which has autopostback set to true. On postback I populate a runat server div with a bunch of other DropDownLists. I then have a button which does another postback to save the selections. Because the second set of dropdownlists are dynamically generated I cannot for the life of me figure out how to get their selected values?
1st DropDownList
[Code]....
Then when I try get the dropdownlists using a foreach on the div that I added the control to it does not work. They are populating fine, its just on the button click. I have tried EnableViewState = true on the dropdownlists and my code is correct because if I code them into the aspx then it works, its something to do with the state.
I have implemented a user control with dropdown lists and textboxes where user may choose to add more of the same user control dynamically then submit the values within all usercontrols at the same time. They way I added usercontrols dynamically is whenever user clicks "add more" button, it increases the value of "userControlAmount" in session by 1, reloads the page and during next page_load event, within an updatepanel it creates usercontrols on the fly.
However whenever more is added since all usercontrols are generated again according to the latest user control counter, the values within the dropdownlists and textboxes are getting reseted.
I can hold all values in a viewstate/session however beyond the time/effort it will take, it doesn't sounds very "professional" to me. I was wondering if there is a more efficient way of doing this.
I have a form that has dynamically generated textboxes using javascript.
My question is how can I read the values of these dynamically generated textboxes since I dont see any HTML in the page source for these textboxes even though they appear in the page.
I tried to read using
var str = document.getElementById('txtHello').value;
It always returns null.
txtHello is the Id which I have given to the textbox when I generated it dynamically using javascript.
I am generating a button dynamically at runtime and in event button click I am generating a TextBox dynamically at the runtime.
My question is I should be able to generate TextBox on every click. Suppose say, If I click three times then there should be three textboxes generated.
I've to implement dynamically generated 'Tests'. It seems the best asp control to handle each's test option is the RadioButtomList control, thus I am writting in c# code to load programatically a table, render on rows the Tests' questions, and the options via radiobtuttonlist as the code bellow shows.
THE PROBLEM's since I did not ID each radiobuttomlist, once the test's end user submit his choices, I do not know how to get the selected item for each control so I can compute the results.
I've recently added a Master Page to my site,but realized that it's caused some problems in my existing JavaScript setup.I am able to use the following code in most places without any issue to get the ClientID: '<%=myControl.ClientID%>'
The problem I have encountere is that I have several pages that add controls dynamically,and then execute events based on an ID that's passed in,where I can't use this line,because I won't know the ID of the control I'm trying to access until the Javascript executes.Here's a simplified version of the problem:
When the page runs,it creates n textboxes dynamically,and appends a relevant ID from the database to the end of the ID.Let's say the page has added 3 textboxes with the following IDs:
myTextBox1
myTextBox7
myTextBox115
Later,a javascript event fires,and I need to be able to access the control through JavaScript like this:
I have a asp.net page where we need to dynamically generate a table, table row, and a checkbox controls in this row. A button serves Add Row and create checkbox function, which works fine. We have another button which serves on deleting the selected row if a user checks the checkbox. The deleting event is dynamically added to the checkbox. But the delete button is not working at all. I think that the page does not maintain the states of dynamically generated controls, even I set Page enable view state to True. Here is the code:
I am generating a table dynamically with one row having four cells.
First cell is having checkbox and below is the code how i declare it and assign it a new id at runtime.
I have a dynamically-generated textbox and a static text box. They both have enableViewState = false. On the web page, I enter "ABC" in both textboxes. In the code-behind I set both text boxes to "EFG" in the page_load event.
In debug in page_load I can see both textboxes say "EFG". This is what I want.
When I hit the LoadComplete event, the STATIC textbox still has "EFG", but the dynamically generated textbox has gone back to "ABC".
I went one-by-one through all properties on the dynamically generated/static textbox, and they are all identical.
