Web Forms :: Dynamically Populated DropDownList Not Working
Jun 3, 2010
I have two drop down lists on my page. One (DropDownList A) has the values preset by me. The other (DropDownList B) has its values filled by a database query if a button is pressed. Each of them have AutoPostBack set to true. Each of them have corresponding onselectedindexchanged functions. DropDownList A works fine. When I change it, I want it to turn itself invisible. It does. DropwDownList B is not working. When I select something, it does the postback but the selected item is reset and the onselectedindexchanged function is never called. I feel like this is a problem I've solved in the past, but it's been 3 years since I programmed ASP.NET. All this is done in C# by the way.
i am currently working on a webform that has several dynamically populated dropdown lists. this works just fine, however, i have other web controls that require to have a postback..and at the time the page postsback, it reloads my dropdownlists, reseting whatever option i had chosen...
Item Selected in MediaTypeDDL determines values in MediaFormatDDL. I'm using Javascript to populate MediaFormatDDL. This is working. I now select the item I want from MediaFormatDDL. That works The problem I'm seeing occurs when I press the button to save the values from the screen. I don't see the Item I selected from MediaTypeDDL. All the other fields are okay. This must be someThing simple, but I'm not seeing it.
I have a gridview which contains a templatefield. Inside this is an ImageButton and a dropdownlist. This is all created in the aspx page, although the ddl list items are populated in the RowDataBound event in the vb page. When i change the selected item in the drop down list and hit the imagebutton, the selected item is not maintained after postback. Instead the first record is displayed in the dropdownlist. I have wrapped an If Not Page.IsPostback around the datasource and databind's but this doesn't help. I have tried enabling viewstate in all areas on the page too, but still nothing. The list items for the ddl must be created on RowDataBound also. As far as I am aware, my ddl is not really dynamic, its just the list items which I add in the code behind which are classed as dynamic.
I'm populating a DropDownList using JS on the client and validating with a RequiredFieldValidator.This works fine on the client but the Page.IsValid consistently comes back false on the server.Is this because the selected value wasn't in the DropDownList when it was first served to the page?What's the easiest way around this? (I need to leave server validation turned on)
I have 2 dropdown lists on a WebForm. One of them is populated in the page's Page_Load event. This oneworks fine with the following code.
[Code]....
Then, after a value is selected from this list and a date is selected from a DateTime picker, then I click a button which is supposed to populate the 2nd dropdownlist. In the debugger in the button's click event I can see that the dataset is being populated with data, but then the list is never populated after the DataBind() method is run. Here is code from the button's click event.
I have a DropDownList populated with a SQL Stored Procedure. On the page, there is also a button that when pressed, processes the contents of the dropdownlist. I would then like the dropdownlist to automatically remove the selection, and if there is nothing left in the dropdownlist, I would also like the button to be disabled.
I've got a dynamically populated drop down list and was wondering if web crawlers are able to see dynamically rendered data? Here is my static html below, and the end result to the end user is a drop down list that's populated from my SQL query within my datasource below.
I have a dynamic dropdown that is populated from sql. The user is supposed to select an option from the dropdown, then click a search button on the form to return some results based on that selection. It works fine if the dropdown gets populated with more than one record. However, if only one record is returned, that one record can't be selected. Whether you select it or just leave it alone since it's the only one, when you click the form button (search button), no results are returned b/c the dropdown selection must not be actually selected.
I've included the relevant code below. First the DDL, then the datasource, and finally the C# code in the if (!Page.IsPostBack)
I have a form with 2 sections. The first one contains some radio buttons. The second one contains a checkboxlist. When we change the selected radio button then it modifies the elements in the checkboxlist. For this I setted the radio buttons with autopostback, and in the code behind (in OnLoad) I populate the CheckBoxList depending on the selected radio button.
This work fine.
The problem is that I also have a button at the end of my form which post the data of my form in another page (with PostBackUrl). Then in that page I would like to retrieve the values of the checked checkbox. But I can't find how to do that. In the Request.Form I don't see anything.
I searched on the web but I didn't found really a solution.
I have the following code which simply gets data from a table and populates the questions_lb listbox with items. I have a button on the page, which when clicked, should write (on submit) the selected state of each of the items. The code below writes the text values of each of the items fine however it always writes the li.Selected as False even though i have selected items from the list. Note that you can select Multiple items from the list. Does anyone have a clue why its not writing 'True' for an item that is selected on submit?
i have a checklistbox that is databound during Page_Init in an
If (!Page.IsPostBack)
block. the user can then check off certain values, and click an asp.net button which posts back the form and renders a crystal report on the same page.
i need to be able to determine which items were checked in the control so that they can be used as parameters in the crystal report. rendering must be done during Page_Init.
the checklistbox object is on the page during design time; only the items are dynamic.
i tried using the Request.Form object during Page_Init to obtain the checkboxlist's items but either i didn't code it correctly or it can't be done that way...
can the checkboxlist items' values be obtained during Page_Init, and if so, how?
asp.net using visual studio 2008 3.5 framework with sqlserver 2008. I have a webform (derived from master page) so its a content form with content placeholder. It has two text boxes, dynamically populated checkboxes from database and 8 radio button groups. It has two custom validators attached with two of my fields also. I've tried every way to clear my form but its not working somehow. I've tried Control iteration method. Ive tried btnReset.Attributes.Add("onClick","document.forms[0].reset();return false;"); thingy...but none is working.
the problem is actually in the subject. I have custom control that uses treeview. The control is added dynamically. Nodes for this treeview are populated on demand. Treeview nodes can be checked. I recreate this control on page load event, but still CheckedNodes is empty if checked nodes were added dynamically (added on demand).
i have one simple question; do I have to... or is there any need to validate value from DropDownLists that are populated from SQL Datatables. I know how to validate them, but I am just concerned about potential SQL Injection, because those DropDownLists are going to be "Input fields" for a new Datatable, and insted of using TextBoxes, user will choose values from those DDL's and Submit them (INSERT INTO) to SQL Datatable. Is there a way for a "hacker" to insert his item value into DropDownList. I hop You understand what I mean!?
I need to populate a dropdownlist with results from a linq query done in my controller. I want users to be displayed but when the item is selected and submitted, the userid is passed back to the controller.my controller:
When I use the code below an error accur when click add button to insert into sql because the selected value in DropDownList is back to --select-- Idon't know why it should be the the value I selectedbut when not use this code and bind the DropDownList using wizard it works but I need to use the code to make the first selection is --select--.
private void PopulateDropDownList() { string constr = ConfigurationManager.ConnectionStrings[1].ConnectionString; using (SqlConnection con = new SqlConnection(constr)) { using (SqlCommand cmd = new SqlCommand("SELECT Country_ID,Country_Name FROM Country", con)) { using (SqlDataAdapter da = new SqlDataAdapter(cmd)) {
Refering to your article on exporting the gridview to Word/Excel/PDF/CSV, I modified to code to populate the GV dynamically coz they have different data and different columns as per the selection. But after the data population, when I try to export the data it does not export any data instead for eg. in Word it just export <div> </div>. The code is pasted below.
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click Dim dt As DataTable = GetData() Dim dcol As DataColumn Dim bfields As BoundField GridView1.Columns.Clear()
My issue is similar to [URL] how-to-use-the-value-of-a-selected-value-from-a-dropdownlist-populated-with-ajax but I am using ASP.NET, not PHP. I have a dropdownlist that is populated by another dropdownlist's current value through ajax. So if DDL A is 'NY', DDL B is populated with different data relating to 'NY'. I need that data to be posted back to the server because this affects an SQLDataSource parameter. However, as far as I can tell, the value is always null after postback resulting in the gridview to be empty.
