Web Forms :: Unable To Get Dropdownlist Control Value At Postback?
Feb 23, 2010
I have 2 - DropdownList controls, which i am filling at severside when page loads. After the user selection in DropdownList1, i am changing the contents in DropdownList2 values. This validation (i.e. changing the contents of Dropdownlist2 values) am doing in Javascript Clientside. But on postback i am not getting the values in DropdownList2. When i say "DropdownList2.Items.Count;" getting "0". I tried to put the contents of DropdownList2 in ViewState on pageload. But i am getting Serialization error at runtime "Viewstate["PersistValues"] = DropdownList2;". I am using html input hidden control to pass the values from server side to clientside for my validation. Now, to meet this requirement i am Binding the DropdownList2 at postback again with first DropdownList1's selected index (This is repeat of logic which i have done in Clientside).
I had use a combox to let user select staff name and then it will automatically retrive the responsible recommending officer and approving officer to display in other 2 dropdownlist.
my code works fine but when user select staff name each time, the page will reload once to refresh the dropdownlist.
user complaint and don't want the page reload every time, how can i disable the postback? I need to use ajax?
I have a tab which loads a usercontrol dynamically and this usercontrol has 2 other usercontrols. One on the left loading treeviewA and one on the right treeviewB.I am using update panel for aspx and the ascx too. But, I am not able to control to page state and moreover when I click on one control, it get its child item, by the time I click on other control, it would refresh other control too and will lose its value.I am using below code in aspx and I have embeded update panels in usercontrols too
using http://msmvps.com/blogs/luisabreu/archive/2006/11/16/adding-removing-updatepanels-dynamicaly-from-a-page.aspx as reference
I need to create a user control which will be loaded according to the selected value of a dropdownlist. The Dropdownlist is not the part of Control. I want to pass the value of selected value of dropdonwlist to my user control and the user control will load according to the Value. For not postback it work fine. But when the page is postback, that is when i select a item form dorpdownlist, the user control is not loaded.
After this, the text box continues to work correctly, but the _state member does not pick up the posted back values and instead just sticks to the declared value. I've checked the raw posted values in the Request object, and the new value for the list's UniqueID is there, but _state doesn't pick it up.
I am trying to add UserControl dynamically to the page. UserControl is added only once (when the page loads) but on postback it doesn't add again (Only one control is alwasys there).I want to add user control Whenever user clicks "btnAddUCWingControl" so when the page loads for first time, there will be only one control, on postback there must be TWO controls and so on
I was trying to disable button after it is clicked once. But I am not sure where I was going wrong. On click of Ok, I am trying to navigate back from ascx to aspx page.
I've got an issue with the postback property. I have a chart (Code below) which has two series pulled from a datasource.
Both series display fine but I've enabled the bars in the chart to respond to the click event and when items from the first series is selected, everything works fine. However, I try to pull the x value for the second series, which is supposed to be a date, but all I get is an interger.
I have a page (page1) with 4 controls that serve as the parameters for a report. The submit button does a cross page postback to another page (page2) that contains a ReportViewer control.Unfortunately, I cannot read the values from page1 once I get to page2. Here is the source to page1:
[Code]....
Here is the handling code on page2 (rvProjectStatus being the ReportViewer control): [Code]....
In other situations I have passed such values in the query string and then assigned them to the parameter collection, no problem.Also, please note, I have tried using the @PreviousPageType directive to get at the types on page1, but have met with no success there either.
I have this webform with few fieldsin the search criteria,I added a new dropdownlist named "Company",I populated it with the data from the database, now when I click search choosing this criteria it doent work.
public partial class List : PrintablePage { private string CNUM; private string CNAM; private string CEL; private string SD; private string SDE;........
This would be a simple one for me if I was binding this dynamically. I don't think it's necessary to have a code behind for only 4 or so values. Anyways here is my ddl.
[Code]....
The problem is that when a user selects a value and it postbacks my ddl resets to the first value. How do I prevent this?
I have 5 dropdpwnlist in asp.net page.. the 5th dropdwpnlist will show data based on 4th dropdownlist. and 4th dropdwpnlist will show data based on 3rd dropdownlist. and 3rd dropdwpnlist will show data based on 2nd dropdownlist. and 2th dropdwpnlist will show data based on 1st dropdownlist... All dropdownlist has auto postback=true.. so it cause postaback each time.. i want to avoid postback coz it refresh all page again and again and shows data.. coz my aplication is in hosting server..
I created a dropdwonlist and add colours to the items. But the colours will lose after the postback. After googled, I knew it is because the attributes specified for the dropdownlist were not saved in ViewState and also found the code to Overriding SaveViewState() and LoadViewState(object) from [URL]
But after I copy the code to my web application to create a new class, there are so many error massages. I have spend two days to find the solution, without much success.
I have a situation where i want to postback and redirect the user to the diffterent page wherever the user selects something from dropdown list. If the user presses the back button the in the browser the dropdownlist should be in the default state. i have already tried this code
protected void ddl_SelectedIndexChanged(object sender,Eventargs e) { int selecteditem = int.Parse(ddl4.SelectedItem.Value.ToString()); ddl.ClearSelection( ddl.Dispose(); //Even tried ddl.selectedindex = -1 ; //dosome postback i.e redirecting the user depeneding upon the value in selecteditem }
I would like to expand dropdownlist after onfocus postback. There is some code that runs when OnFocus is fired off then it needs to stay expanded so the user can select an item from dropdownlist. Currently it expands and contracts real fast when user clicks the dropdownlist, then the user has to click it again to select an item.
I am having trouble with a dropdownlist and it's values not getting updated after postbacks.
Situation: I have an ASPX page that contains 2 user controls (UC1 and UC2). When the page first loads, controls on both UCs are set properly. My problem comes from the fact that when a dropdownlist on UC1 is changed, I need to reload a dropdownlist on UC2 (based on the new value). I am raising an event from UC1 to the parent page when the dropdownlist value is changed and inside this method I am telling UC2 to reload it's dropdownlist based on the new value. When stepping through the sequence of events using the debugger, the values in the datatables and dropdownlists (item count) are 100% correct but after running through the logic, the dropdownlist on the page still has it's old values.
The initial values for the dropdownlist in UC2 are populated in Page_Load of the ASPX page, and nothing is done to the dropdownlist in Page_Load (!Page.Postback) of either the ASPX page or UC2. The only way I would like the values to change is when the event from UC1 is raised back to the page.
I have found a couple of other forum posts out there that had the same problem but I've tried those resolutions and nothing has worked. In the following examples, the value dt is the 'new' datatable that I wish to bind to the dropdown.I read that before rebinding the dropdownlist, that the Items need to be cleared and the SelectedValue should be set to NULL:
I've created two datasources, one that gets a list of categories and it's id's and the other one get subcategories and it's id's. The categories are presented in a DropDownList and the subcategories in a ListBox. When choosing a category from the DropDownList the ListBox presents the subcategories of the chosen category. The subcategory datasource is set to get it's value for what category to get from the DropDownList's selected value.
My problem is that when I change the category in the DropDownList the subcategories doesn't update on a postback. Instead I have to press a button on the page that I know performs a postback to get the subcategories to update. What am I doing wrong here? I'm using this method on another page as well and when comparing them I can't find anything different. Any ideas?
i have two radio button list on my page on my Frist Index there is a panel with Drop Down List and on Second Index there is a static variable in which i am storing value as Pending
now as soon as i select my Second RadioButtonList it also stores the DropDown List Value
My page has a gridview, and the gridview has a TemplateField called "Acciones" (Actions). The column Acciones has a ImageButton with CommandName "Select" and CommandArgument "Tutor". Thus, the GridView has controlled event "SelectedIndexChanged". The idea is that in GV_SelectedIndexChanged, I must to set DropDownList's SelectedValue property. But, the value seted in this function don't affect the rendered dropdownlist. The debugger talk's that the value is correctly seted, but the visual result don't.
