C# - Binding DropDownList's SelectedIndex To 0 If Value Does Not Exist?
Mar 17, 2011
I have a DropDownList in a DetailsView, which binds a user's 'AllocatedUser' to a user in the Users table. Occasionally, we'll have some mishaps in the database where the user allocated isn't in the users table, which the DropDownList is filled with. In this case the site crashes and we get a 'SelectedValue does not exist in the list of items error'.What I want to do is catch any binding errors like that, and just set the DropDownList index to 0. I've tried something like this:
I'm having trouble binding my textbox to my dropdownlist. I got it to work but I don't think it is the correct way of doing it. I have my DDL bound to a datasource and populating everything correctly. However, I couldn't find a better way of binding my textbox to it besides using the FormView control and its counterpart, Templates (edit,insert,etc) It looks messy and i was hoping there was a better way of doing it. I've researched it online for awhile now but I couldn't understand how to implement for my situation.
My DDL has company names in it and the datasource has all the information from the table including what I'm trying to have my textbox pull (Address).
I have an issue that I haven't been able to figure out - I have a DropDownList control within a WizardStep that is populated dynammically. It properly shows the right list of items, but when I select items it sometimes (not always!) moves the selection to a previous item. E.g. there are 3 items in the list and when I choose the third it changes to the second.
Below is the section from my aspx file and the code-behind file where I am detecting the incorrect index:
I have a DropDownList bound to a sqlDataSource, and a TextBox that is to receive a value from a DataSet upon the DropDownList Selection. Each time the first selection of the DropDownList is selected the value of the DataSet second row(1) is passed to the TextBox instead of passing the value of the first row (0). See Code Below.
I have a drop down list of all the users in a particular role.
The problem is, when I try to access the selected index/item/value, it always selected the first name in the list and never the one that the dropdownlist has been changed to. None of the following solves the problem:
I have a form with a dropdownlist named ddlCustomer. When the page loads I want to set the selectedindex to the 1st item in my ddl and then call a routine that updates the form to the data for that customer. I have tried the following code, but the ddl selectedindex remains at -1. How do I get this to change?
I am trying to set selectedindex/ text property for DropDownList that is attached to CascadingDropDown, which does not work.Then I tried setting SelectedValue property of CascadingDropDown, which also does seem to work
Is there any way I can change selected item in the dropdown in the VB code file during runtime?
I have a repeater with a DropDownList in it. I set the datasource of this list in the itembound event en set the selectedindex. When I debug the selectedindex is set, but when the page is done loading for all the item the default item is selected.
I wanted to create a dropdownlist that would trigger an asynchronous postback and update the Gridview inside the Updatepanel. However, no matter what I do, when the dropdownlist changes, nothing in the UpdatePanel will change, even the TestLabel....I've been banging my head against the walls for days on this -- why won't this work? When I remove the UpdatePanel code and triggers, all the code works, eg, you change the dropdownlist andthen gridview updates -- but it refreshes the page and this is why I wanted to put the Gridview inside an Updatepanel to make it look cleaner.[Code]....
I have a datalist where each item consists of a textbox and a dropdownlist. I want to get the datakey value when a selected dropdownlist item changes. I can get the selected value of the dropdownlist, but I can't figure out how to get the key field value of the datalist row item that the dropdown resides in.
I'm trying to do a similar thing -- I have a long form and in part of it, I have an updatepanel.
Inside the updatepanel I have:5 dropdowns (using the CascadingDropdown functionality)One AddProduct ButtonGrid or Repeater (haven't set it up yet)
I want the following to happen:I have the AddProduct Button disabled initially, but I want it to be enabled once the 5th dropdown is selected (so OnSelectedIndexChanged).If they click the AddProduct button, I want it to populate a Grid or Repeater.So far I am just trying to show what the selection was in a label... but nothing happens. I have an OnSelectedIndexChanged function for the last dropdown, so it enables the button, but that doesn't appear to get called. Previously, before disabling the button, I tried updating the label on button click -- and nothing there either.
It just seems like, because they are in the updatepanel, those callbacks never happen. I also do have UpdateMode = Conditional and I have both items in the triggers list.
when i change page from page1 to page 2 I remember Dropdownlist in session
now when i go back to page1 I set the Dropdowlist the way what it was before i left page1
Everything its remember but when i load the page with my Dropdownlist again. The selectedindex shows default value in the control Dropdownlist.But it does remmeber old selectedindex.I got it wired with Gridwiew and gridwiew show Data by remmeber old selectedindex. Well generally I like to remember selectedindex when i go to a differente page and when i go back have it set in the control dropdownlist the way when i left the page
i have two dropdownlist.i bind somthing to first dropdownlist from database.I want when I select an item from dropdownlist1 see some item in dropdownlist2 .but when i select item from dropdownlist1 ,I give this error.
i wrote this code but it doesn't work.
for binding item to dropdownlist1 i wrote this code:
I have a page with some bound DropDownLists (DDLs) for a Call Logging system. The Calls are categorised on three levels for example:
Call: 3069, Category 1: Incident, Category 2: Microsoft Application, Category 3: Word would be used to organise calls for problems with Microsoft Word. On testing the system, I noticed that there was no handling for opening a call if the category had been deleted - say for reorganisation/systems no longer supported whatever. So I set about trying to make the program behave in the following manner:
Check category ID exists in DDL before bindingIt doesn't: set the displayed text of the DDL to Category Name + "(Deleted)"Disable the control to prevent user changingMove on to next control Seemed simple enough, however no matter which way I try and do it I always get the messase ddl_Cat1 has a SelectedValue which is invalid because it does not exist in the list of items. What's really puzzling me is that the exception doesn't seem to be being thrown in the code behind. I've gone through line by line from Page_Init and it never throws and exception. Just when the page loads this appears.
Does anyone know of a reason as to why this wouldn't work? (I've already tried setting the selected value to an existing item, adding a new list item with the value and setting DataSource property to Nothing - in all different combinations.)
I have a drop down list inside a formview control's edititemtemplate and itemtemplate. The dropdown list is not bound to a data source. I am hard-coding the listitems for the drop down list. The formview is bound to a datasource. All I want to do is set the selectedvalue of the dropdown to what is in the record from the database. But I keep getting the error.
<asp:formview .....> <edititemtemplate> .... //some other controls like textboxes that are correctly bound and display the value from the datasource <asp:dropdownlist ID=myddl runat=server cssclass=myclass selectedvalue='<%# eval("mychoice") %>'> <asp:listitem value='0'>I dont know</asp:listitem> <asp:listitem value='1'>Yes</asp:listitem> <asp:listitem value='2'>No</asp:listitem> </asp:dropdownlist .....//rest of the edititem controls that display correctly. </edititemtemplate>
Just for kicks, I added a textbox and set it's value to eval("mychoice") as well and it correctly prints 0,1 or 2. So, I know that there is no illegal value coming back from the datasource. It seems as something with the timing of events - when the listitems are getting bound to the ddl. The error I get is - "myddl has a selectedvalue which is invalid because it does not exist in the list of items".
I have a standard gridview and detailsview. My detailsview has some fields which are templates, with dropdownlists. The user selects a record in the gridview, then can go down to the detailsview, select Edit, and change some values (using dropdownlists).I am getting the error, "DDL has a selectedvalue which is invalid because it does not exist...." when I click Edit in the detailsview.
I know the problem has something to do with the dropdownlists not being instantiated or bound until I enter Edit mode. Is that right? In what event should I databind my dropdownlists? I've tried several things but could not get it to work. Do I have to loop through all the rows of my details view looking for the dropdownlists, or can I access them directly from some event?
Code: /*This Stored Procedure will create get the resources based on the ID and the Type of Resource */ ALTER PROCEDURE sp_Get_Resource_Based_Type_ID
because the Dataset in the load event of the Usercontrol will only be available , i created a Glabal dataset that will be accessed by the event RowDataBound in order to bind the dropdown list. If there was a way i know to bind it like other template fields i would have done it in the same place. Now my problem is that the Dropdown in the Grid is Showing duplicates like as depicted in this photo ,I want each Record to have only one record
I have placed a dropdown list in the edititemtemplate of a formview control and followed specific MSDN instructions on how to bind the list source to a separate SQL lookup data source but have the formview bound to the main data source. If I set the selecteditem value to bind to the formview control I always get the following error:
'DropDownList2' has a SelectedValue which is invalid because it does not exist in the list of items.