Web Forms :: Getting A Dropdownlist To Dropdown With Code?
Jun 28, 2010
In MS Access there is a great method call 'dropdown', you set the focus to the control, mycontrol.setfocus and then call mycontrol.dropdown, really useful when using cascading dropdowns.
Is there a similar method in asp.net or how would I get the dropdownlist to dropdown through code?
I am currently writing an MVC app and currently only have one master page. I would like to add a dropdownlist to my main page and on selection of this to be able to switch the master page used. Has anyone acheived this before. I am unsure of how to force the onchange in the dropdown to fire some code behind in my controller.
I have many controls on my form, but in particular, I have 2 dropdownlists. 1 dropdown list has 2 values, and each value controls what the second dropdownlist displays. This is an edititemtemplate and both dropdowns have the selecteditem set via '<%# Bind("fieldname") #>' on page load.
THe problem is, if I change the value of the first dropdown, it errors out because the second dropdwon has a bound value that is no longer acceptable.
Can I cancel the bind of the second control, if the the first one is changed? I would like to cancel the bind, and update the values by using a different datasource depending on the value of the first dropdown or hardcode the new values.
If Dropdown1 has a value of "A" for example Dropdown 2 Shows Values "1", "2", "3"
If Dropdown 1 has a value of "B" , Dropdown2 Shows Values "4", "5", "6".
It binds fine initially, but if I change Dropdown1 from A to B, I want Dropdown2 to show the new values, maybe with a default of "Select an Item" and not error out b/c it's attempts to bind a value of 1, 2, or 3.
i have dropdownList Binded to a data source and its working fine But want i want to do is when the page loads its initial value should Blank until clicking the dropdown button
I have some dropdown list boxes that I need to fill with data from a database but I also need the first option to be "Show All"... So I need to combine using a datasource and manually adding an item to the top of the list. I have tried two different ways with no luck:
1. with the appendDataboundItems = true, on aspx page, and below code in codebehind:
I have a dropdown which shows filesnames and when the index is changed, the slected file is offered for download. I also have a button which creates new files ... now after a new file was created, the new filename should also be shown in the dropdown. It works fine, when I refresh the page, but this is not what I want. I tried putting the dropdown in an updatepanel and giving it the file create button id, it failed ... is this the correct apporach or is there an easier way?
I was wondering if it was possible to change the background or text color of an item in the list based on it's value? I just noticed that the example below works when the page first loads but on postback the text color disappears even though that is where the code is. Is there something I am missing?
I need a develop a smart dropdown list for an inhouse application
Let assume, i have a dropdownlist with the following values:
ABC EDF XYZ A123 B456
Now when the user types A in the drpdownlist (we can type anything onthe dropdownlist, but we can superimpose a textbox on it), the dropdwn list should sort itself and show only ABC and A123.
I have two DropDownLists; DropDownListStart displays the hours 09:00 - 19:00 and DropDownListStop displays 10:00 - 20:00. When the user chooses one of the hours in DropDownListStart I want the program to adjust what's shown in DropDownListStop so that the first hour shown is one hour after the hour chosen in DropDownListStart. How can I do that in code behind (c#)? An example: if the user choses 13:00 in DropDownListStart I want DropDownListStop to display only 14:00, 15:00, 16:00, 17:00, 18:00, 19:00, 20:00.
I am generating a dropdown list in codebehind and cannot get the selectedindexchanged event to fire automatically. It works fine when put directly into the ASPX page, but I need it to be in the codebehind.
My problem is that some of the users that used to be in the list have left the company so we want to mark them inactive. When they are inactive they should not show up in the DDL to be selected to be assigned to. But there are existing records that they are already assigned to. If they are no longer able to be assigned their is a column called IsActive in the db that is set to 0. The Datasource filters for only == 1 when filling the datasource.
When it tries to render the control where a selected value is not in the list the Browser throws an error. I can not seem to find an event where I can intercept and set a value that is legal.
The solution I would like would be to add the listItem to the Control in the code behind then call the bind("AssignedTo") in the code behind instead of in the aspx page. This way linq would still handing the update of the DB record for the update event.
On my formview I have a drop down list that is populated with the names of the files in a certain directory. This works fine, but when the drop down list selected value is bound to the database field I get the following error :
'ImageFileDropDownList' has a SelectedValue which is invalid because it does not exist in the list of items. Parameter name: value
I have setup other drop down lists in the same formview populated from SqlDataSources and these all work fine. I can see perhaps why this is an issue because I have not specified a DataValueField or a DataTextField for this drop down that is populated in code (whereas I can for the SQL bound ones) because I'm not sure what these settings would be.
I need to have a "blank" option as well so that the field does not default to the first value in the list.
My code (I have stripped out some meaningless controls) :
Have spent hours trying to create a Dynamic Data Field Template holding a DropDownList which is extended by the AJAX Cascading DropDown extension.Final form holds multiple cascading dropdown boxes. User selects Country (Land) then Postcodes, Counties (Provincie) are populated. Once postcode is selected then towns (Plaats) are populated. The problem I am now facing is that the viewstate for the dropdown lists is not being saved/restored after an insert action or custom validation error. So basically the dropdown lists are being reset to their default values.Some code (if missing parts, just ask and I will post them) - Don't mind the code structures etc... needs some refactoring :)Attribute I created:
[Code]....
KlantMetaData (=> Klant is Dutch for Customer ):
[Code]....
DynamicDropDownList Control I created: [Code]....
Dynamic FieldTemplate created for inserts: [Code]....
I select a item from gridView and trying to show/update/delete in From view. In Form View I am using the dropdownlist filling it in Code behind. Then i bound the list. But the problem is it is not showing the slected value. Here is the code