Web Forms :: Setting SelectedValue In Dropdownlist
May 11, 2010
I have a ASP.Net webform with a DropDownList control. This Dropdown gets it's values from a states table in an ObjectDatasource. The Dropdown contains states spelled out.
If I try to set the drop down to:
DropDownStates.SelectdValue = "Ohio"
I get an error that the value does not exist in the dropdown even though it does exist. But if I pad the value with the correct number of spaces to the right, it works like so:
DropDownStates.SelectdValue = "Ohio "
or
DropDownStates.SelectdValue = "Michigan "
How can I either define the dropdown without trailing spaces in the value of the dropwdown or set the SelectedValue with adding trailing spaces?
I have a WebForms page that has two DropDownList controls on it that both contain a range of temperatures from 60-80 degrees, one for heating the other for cooling. They are declared in the .aspx as:
When I try to set the selected value for each DropDownList using the values in an object containing data loaded from the database using:heating.SelectedValue = myHome.avgHeatingTemp.ToString(); cooling.SelectedValue = myHome.avgCoolingTemp.ToString();
The SelectedValue for both lists is set first to the value in myHome.avgHeatingTemp, then to the value in myHome.avgCoolingTemp. Heres what the values are for each variable after each step of the process of setting the SelectedValues:
Initial State heating.SelectedValue: 60 cooling.SelectedValue: 60 [code]....
I'm populating a dropdownlist in a formview with a different datasource from the formview's. I need to set the selected value according to the value in the formview's datasource but I'm having a hard time doing that.
Here's the code: <asp:FormView ID="FormView1" runat="server" DataKeyNames="ID" DataSourceID="SqlDataSource1"> <EditItemTemplate> [code]....
I have officially wasted about two days trying to figure out what the heck was going on with my asp.net page. I actually thought it was an issue with my updatepanel code, but after reading another post I was able to reproduce the same results. [URL]
I just manually added the following control to the page (no code behind for the listbox) and it is nested in an ajax tabcontrainer inside an updatepanel. If you set item 20 as selected the page flickers when loading that tab. I tried the css mentioned (style="overflow:hidden") on the tabcontainer,tab panel, update panel and dropdownlist, but no luck. Crazy select item 19 no flicker, 20 (which is actually the 21st item) and it does flicker. This is driving me insane. And yes this only occurs in FireFox ( running 3.6).
In our asp.net web application we load the dropdown list boxes in the page load. We than set the SelectedValue of each dropdown list box to an object from session. We have event handlers for many of the SelectedIndexChanged events of the drop down lists boxes, but these do not get executed when we set the selected value programmatically.
Someone else mentioned this is by design, and only when a user manually changes the drop down list selected index, will the event get raised.
I would think this is a common scenario of wanting the selectedindexchanged event handled when setting the selectedvalue/selectedindex/listitem's selected property, of a DropDownList. What is the suggested way to handle this? Is there a significant drawback of creating a custom control inherited from DropDownList that has the functionality of raising this event when changing the SelectedIndex or SelectedValue?
I binded the dropdown from the table Languages, now it shows all the languages:
ViewData("Languages") = New SelectList(objLang, "SysLanguageID", "LanguageName")
Now when I click the edit then the dropdown should show the selectedvalue based on the languageId that is in stored in the Preferences table under the user.If i give the third parameter as the selectedvalue it is showing the selected value but it is not showing the other languages.
I have a databound dropdownlist on a page, where in the page_load I set the selectedValue (inside a 'not isPostBack').
Although the page displays fine and shows the correct item as selected.. inside the page_load if I try and get the selectedValue() and display it to the screen, I always get null... selectedIndex is -1.
I have a button, which when clicked refers to this ddl's selectedValue, and here it pulls through the the expected result.. so how come I can't see it immediately after setting it, while still in page_load?
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load dlCountryList.SelectedValue = "GR" Response.Write("*" + CStr(dlCountryList.SelectedIndex) + "*") End Sub
I have a bit of a problem with a DropDownList I am using. When the user changes the SelectedIndex, they get redirected to the same page, but with a query string on the end based on their selected value.
Because I'm not posting, and redirecting instead, the state of the dropdownbox is not saved, so it always defaults to the first one.But, if I save it in say a session, or set the selectedvalue according to the query string in Page_Load, when the user selects another listitem, the selection they have chosen is overridden by the selection delcared in Page_Load.
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 have a dropdownlist in DetailsView to which items are added programmatically during DataBound event. It is working fine in InsertItemTemplate, but in EditItemTemplate i am getting this error "'branchDDL' has a SelectedValue which is invalid because it does not exist in the list of items. Parameter name: value".
I have a query that references many tables, however the main record doesnt necessarily have records in the other tables. In my formview itemtemplate, i bind the values of the query but I'm getting an obvious error when the value is null. This is what I'm trying to do: (the field is a boolean btw). These fields are hidden so I don't really care if it gets assigned a temp value or something.
[Code]....
Error: BC30452: Operator '=' is not defined for types 'Object' and 'System.DBNull'.
I have a dropdown list that has a bind on it and I get this error. Why am I getting this error and what can I do to fix it. here is the code for the dropdown I currently have:
In SQL, you can create a query and use a "IN".. Select * from tOffices where OfficeID in ('1', '2', '3'). Is it possible, in my vb.net code behind to check if a selected value is "in" a list of values like this?
If ArrangementID.SelectedValue in ("6","7","99") then...
I have a quick question on my ddl. I have a search page that searches based on the ddl. Once the button is clicked. the result of the search shows on the gridview.Which all works well.Now the problem i am having is that. On my gridview i have a select button that brings out another ddl on an update panel based on the first ddl. When i do this... it goes back to the first record on the ddl and shows a wrong result.. Basically the new ddl is supposed to change on "selectedindexchanged" handler of that gridview which works fine but the selectedvalue is just going back to the first one.
i am using one dropdownlist for showing deptname from DB using cascadingdropdownlist and web services.i want when i select dropdown value it should be display in textbox.but don't know how to do this.tell me what is c# code for this.
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.
i want to display selectedvalu on dropdonwlist i have a access table like this;1 Adana2 Ankaraits displaying the numbers of cities but i want to display name of the cities in my gridview how can i fix that ? im using theese codes for register page;
string baglan =DugunSitemiz.Properties.Settings.Default.baglan; OleDbConnection conn = new OleDbConnection(baglan); conn.Open();
I have a dropdownlist whose values are int (actually they are string basically but they can be parsed. they are 1, 2, 3, 4, 5.. etc)
I want to create textboxes acording to the number of dropdownlist selected value. Lets say drop down shows 3 and I wanna create 3 textboxes. how can I do that.
I'm using a FormView which has odsMain as the datasource. I am also using a dropdownlist which is being populated with objectdatasource odsddl.
I'd like to set the selectedvalue of the dropdownlist with the value contained in odsMain (the current record value for it). Is there any way this can be done?
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.)
