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...
what can i do to resolve this?
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.
View 12 RepliesSample Code.
<asp:DropDownList ID="MediaTypeDDL" Width="306px" ToolTip="Select Media Type" runat="server"></asp:DropDownList>
<asp:DropDownList ID="MediaFormatDDL" Width="306px" ToolTip="Select Media Format" runat="server"> </asp:DropDownList
<asp:Button
ID="btnUpload"
runat="server"
OnClick="btnUpload_Click"
Text="Upload"
/><br
/>
protected void btnUpload_Click(object sender, EventArgs e)
{
String strMediaFormat = MediaFormatDDL.SelectedItem.ToString(); // Not seeing value here!
}
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.
View 11 RepliesI'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)
View 1 RepliesHow to retrieve selected value of dropdownlist in gridview when dropdown is added dynamically from database.
View 1 RepliesHere is my attempt:
[Code]....
I have a C# web application that dynamically adds user controls to the default page for whatever "mode" the application is in. The problem is that it is not persisting these across postbacks. How do I persist these across postbacks and keep the content of the controls that are in the user control?
For instance, say I have a user control that creates a new tour record. The user clicks on the Tour item from the menu on the default page, it dynamically loads the tours user control. The user then fills out the form in the tours user control and clicks save. This is where the problem happens. When the postback occurs, the web application has no idea that the new tours user control was ever loaded. So, no save takes place because the Save button's click event never even gets fired.
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.
[Code]....
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.
View 5 RepliesDropDownList Not Being Populated
[Code]....
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.
View 1 RepliesDynamically populated Radiobuttonlist?
View 1 RepliesI 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)
[Code]....
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?
[Code]....
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?
On a dashboard page I'm loading several controls dynamically; the controls always need to be loaded so there is no if (!Page.IsPostBack) code. The problem though is in that in the code-behind, we are using Request.Form.GetValues and a particular dropdown field's value is always null (presumably because the controls are being cleared and reloaded on a postback) and this is triggering an error later on in the page that expectes a value from this dropdown. I have to use Request.Form.GetValues because the page enables dynamically adding rows (each row containing 5+ HTML inputs) via Javascript.
If I check for postback, then the button event of the control does not fire at all but instead the dashboard page is reloaded, and no controls are loaded at all (i.e. the page is blank).
How do I get around this issue? I need to dynamically load the controls at all times, but I also need to retrieve the values via Request.Form.GetValues.
EDIT
Here's what the code looks like, roughly:
(Client-side HTML)
<table>
<tr>
<td align="center">
<select id="Class1" class="txtboxcomm" name="Class1" runat="server" />
<a href="javascript:classFinder('1')"> Look Up</a>
</td>
</tr>
</table>
<div id="action">
<asp:LinkButton ID="ibtnGetQuote" runat="server" OnClick="ibtnGetQuote_Click" CssClass="getQuote" AccessKey="G">Get Quote</asp:LinkButton>
</div>
(Server-side, in ibtnGetQuote_Click - this is actually a loop since user can append multiple rows; "i" is appended to the word "Class" to find the exact row)
IList<string> classes = this.GetFormValues("Class1");
// This will return null all the time...
private IList<string> GetFormValues(string clientID)
{
String[] values;
values = Request.Form.GetValues(clientID);
if (values == null)
{
Control ctl = FindControl(clientID); // uses built-in FindControl method
values = Request.Form.GetValues(ctl.ClientID);......
The original code was hardcoding the "ctl00$xx$xx" stuff, but the control may or may not be loaded so we cannot guarantee the name the control will get. In fact, I'm not even sure if this will work for all scenarios since only the FIRST control is a server control, the rest are just standard HTML controls so wouldn't have a "ClientID".
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.
View 4 Repliesthe 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).
View 2 RepliesCan I dynamically create controls in Silverlight without a postback to the server (even an asynchronous one). Does silverlight drag-n-drop requires postback?
I'm asking this because I've an asp.net application where I dynamically create/delete lots of controls. So after the postback I'm getting error with view state stating that the control tree doesn't match the view state tree.
Can I avoid such problems in Silverlight?
i have a user control that includes a dropdown list its actually a page navigator when the user press next page iam setting the index of the selector to the value of a hidden textbox where textbox is filled from javascript function. ex txtbox initially is 1. then when next pressed it is 2 and so on but when doing postbacks i.e pressing next it is not changing the index although in the debuy its showing its setting to the new value. as if there is something that is reseting it to the initial value after the page loads if i put my method in the prerender method its working fine. but in the page_load method its not updating to the new index changed. i need to put it in the page_load method as i have to register some event handlers for the navigator.
View 5 Repliesi'm using jQuery to populate an cascading dropdownlist. But i want to set a selected item after jQuery filled the DDL with items.
View 20 RepliesI have added some combobox and texboxes in gridview dynamically to provide the data entry like operations.i have fetched and reset the value of these dynamically added controls on button click as ->
[Code]....
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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!?
View 6 Replies