Web Forms :: DropDownList Not Keeping Last Value On PostBack?
Apr 6, 2010
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've many input elements one of which is, a radio button group with Autopostback set to true. After selecting one item from the radio button, the drop down list below fetches values from database and is refreshed. I choose some value in the dropdown list and submit the form. I've many server side validation controls. When I submit the form, if any of the server validation fails, it'll show the error message in the form. But the value I choose in the dropdown list disappears and it shows the first value of the dropdown list.
How to show the selected value in the list after submission of form?
Below is the partial code from my form. When I type anything other than "Hello" is the "Comments" text box, it will show the error message. I know I can use, other validators to check this. But purposely I want to use Customvalidator.
I am having problems getting my head around this, so my terminalogy might be off. What I am trying to do is have a dropdown list with different groups, and then two listboxes that run queries based on the selection from the dropdownbox. The left listbox shows all items except those which are in the selected group. The right listbox shows only those in the selected group. I also have two buttons - one to move selected items from the left listbox to the right listbox, and another to move items from the right to the left.
My page has a dropdown list for Groups, populated with 2 records - Group A & Group B. Autopostback is set. When I change my selection on the dropdown list, my two listboxes do change
The problem comes in when I select items in the listbox and click on the transfer button. The records do transfer correctly (that is to say the database query executed correctly and data is moved), but the List boxes are not updated. What I want is to have the form refresh, but there is no AutoPostback for the Button object.
I tried inserting a Response.Redirect back to the same page at the end of the button click event. I thought this would allow me to process the sql command, and then refresh the data. This almost works. It does refresh the listboxes, but it also resets the dropdownbox to the first entry. This in turn changes what is displayed in the listboxes. The data is moved correctly though.
So at this point I have my choice. If the dropdown box behaves and does not change, then the listboxes don't update. If the listboxes do update, the dropdown box resets to the default value.
I have a cascadingdropdown which works fine using a webservice and is populated. I can save the value of this dropdown to the database buy clicking a save button. However when the page reloads, the list is populated again. Is there a way to keep/set the selectedvalue after postback?
I've got a gridview which contains a dropdownlist. I've got it binding to display the correct name, but when I go to update it (and it could be the dropdownlist field or any other the other fields), I get an error stating it can't update the row because addr_cnt doesn't allow null fields. I've tried just about everything I can find to get it to keep the addr_cnt value, but nothing seems to be working. My code is below:
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 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
Using VS2008, .NET 3.5, and C#. The page contains (among other things) a dropdownlist and an objectdatasource. The Page_Load event fires the objectdatasource's Select event. The Selected event iterates through the returned datatable, feed each row into a ListItem, checks to see if a certain column is True or False and, if true, changes the styling for that row to color:red. Finally, the listitem is bound to the dropdownlist. The end users sees all of the dropdownlist items that are false in black and the items that are true are in red. Works perfectly. However, as soon as any item is selected, the page does a postback and the font colors in the dropdownlist revert to the default black. Is there a way, other than rerunning the method that iterates through table and creates the listitems, of maintaining the coloration of the items? Is there a ViewState setting or something?
Here is the dropdownlist and objectdatasource's Selected event:
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 have been having some trouble with dropdown lists reverting back to selecting the initial item in the list after a postback once a selection has been made from the dropdown list. I have read up on this and found out that a "if not ispostback then" is required.This works fine when I add in all the items in the dropdown list manually like:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not IsPostBack Then ddl1.Items.Add("Select...") [code]....
However, I have over 250 items and so it is far more efficient for me to load then in by using part of a multidimensional array which is created from a text file - Definitive database.txt. I have been using the following code to do so:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load If Not IsPostBack Then 'loads the definitive database array[code]...
This loads all the items into the dropdown list perfectly, but now every time a selection is made, it reverts back to the inital item on postback even though i have included the "if not ispostback then" part.
I have 1Dropdownlist 1 button and 1 datalist in my page i bind my datalist in Page_load event that show all my product from my DB ... Users can select their city from DDL click on button and in datalist just show product that are on selected city ...
Problem: when users select PARIS from ddl in datalist show product from selected city and when users want change their city from ddl before their click on button to show that city's product page load again and it show all product again...
I want when users change ddl.selecteditem in datalist show last result of user's selected not the result that i define in page load ... This is my code on page load ...
protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { DDLcity1.Items.Add(new ListItem("select your city", "")); BindDropDownList(DDLcity1, "Guidcity", "cityname", "ID"); }
I have the problem with dropdownlist value inside gridview.my problem is i have textbox,button with two dropdownlists, dropdownlists are inside gridview.Two dropdownlists are one is ddlcountry and another one is ddlstates. if i select country from ddlcountry , country related states comes in ddlstates. after entering first record value in textbox then button click textbox value is shown in gridview with two dropdown lists dropdown list, after selecting one dropdownlist country and states, i enter second record value and button click then only country selected value visible ddlstates selectedvalue not visible in first record in gridview...
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.
I have 2 dropdownlist controls (ddl1 and ddl2). When I pick an item from ddl1, it will update ddl2. The problem is when I pick an item in ddl2, it always selects the first item in the list. Is it that the ddl2 autopostback causes the first ddl1 to reload and results the ddl2 to be refreshed also? Or I didn't set something correctly?
I have a DataGrid that has a dropdown list in an ItemTemplate. Basically, users select a value from the dropdown for each row of the datagrid. When the page is posted back, the selected index of the dropdown list is always reset to 0, and the items are re-bound.
Does anyone know why this might happend? The dropdown items are hardcoded, so there is no external data binding that happens on post back.
[URL]Initially if I make a selection it will automatically post back and firecboItemsPerPage_SelectedIndexChanged. If I then post back by clicking one of the other buttons on the page, cboItemsPerPage_SelectedIndexChanged will continue to fire, despite the fact that the value has not been changed.I want it to be postback only when selected index is changed, not in every postback
i have a gridview which consists of databounds and dropdownlist control. When I press the Add Grid Row Button, it will insert a row. Now my question is, if the user selected an item in dropdownList in the firstrow and the user click the AddGridRowBtn Again which will generate the 2nd row, how would i maintain the selectedItem in the dropdownlist after postback?