Forms Data Controls :: Databinding A Dropdownlist Within A Gridview?
Mar 29, 2010
I have a gridview in which I have two drop downs. One is populated with values that are static, so I have a regular sub that does that in the code behind. I tried to add code for databinding the other ddl to a datatable. I cannot get this to work. It just comes up empty. My asp code is fine, and the datatable definately has data in it - just nothing gets populated.
One other thing - the code for the static ddl has worked fine, but when I add this other block (either to the same sub as that, or dow the rowdatabound event) the static one doesn't work either.
I am trying to create a Gridview in which I can update the Project Officer name in the Gridview from a DropDownList.
The Project Officer DDL comes from a seperate query (SqlProjectOfficerName) as the other information (SqlDataSource1)... as you can see below.
When I select EDIT, the DDL appears and I can select from the list of Project Officers, but when I select UPDATE, the name of the Project Officer doesnot change.
review the code below and assist as appropriate to write the Project Officer's name back to the table.
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.
Bringing back to life an old post that I dont believe ever got solved: http://forums.asp.net/t/1562245.aspxThis may be an old thread .... but no answer was ever given ... and I too have a radio button list and DDL and am stuck in the EXACT same place. If I check one of the two data bound radio buttons, the DDL should repopulate with a different set of results. This works just fine EXCEPT .... the DDL cannot be databound. If I set SELECTEDVALUE of the control to a bind I get this error:Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control.I have followed the advice on this page from various users, all to no avail....surely this can be done, and I assume quite simply. Anyone know the answer?
I have a formview that has several dropdownlists in the EditItemTemplate. Some of the dropdownlists are added using placeholders. I can add and populate their listitems without any problem. But when I update the record, none of the controls can be found--even though when I look at the page source they are there. I first strated out using asp:ControlParameter in my sqldatasource updateparameters, but even referencing the control as myform$mycontrol did nothing. So then I moved to code behind on the sqldatasource.updating event (code is attached). The only controls I cannot seem to bind to the update are those added via the placeholder.
[Code]....
The item at the dim statement is not an item added using a placeholder and does not get a null reference exception (I used that to prove during debbugging that I wasn't losing my mind)--however, all the items being used to get the parameter values are getting null reference exceptions and are added via placeholders. Here is the code I'm using to set up the dropdownlists:
[Code]....
how to get the value of these controls so they can be used in my update?
I'm trying to extend the GridView control to enable sorting and paging for any situation.
When using my control I am fetching data from a database and filling a DataSet with it, then binding the GridView upon every page load. My first question would be, is this the correct approach?
To sort the GridView I am overriding the OnSorting method which stores the sort expression and direction in the ViewState, then creates a DataView and utalises the Sort method to sort the underlying data. It then sets the Data Source to this DataView and rebinds the GridView.
Paging is handled by OnPageIndexChanging which simply sets the PageIndex property and again rebinds the GridView.
My problem is; when any control causes a postback my GridView is no longer sorted, presumably because it is persistently rebound. If I don't rebind it then the GridView is empty on postback since the data isn't automatically stored in the ViewState. I have considered saving the data source in the ViewState but I would assume that this is bad practice for large amounts of data? - also DataViews are not seralisable.
The only solution I can think of currently is to override OnDataBound and sort the data every time. This results in a double sort when paging triggers a postback which seems inefficient. Code illustration of this below,
[Code]....
I'm looking for the cleanest 'best practice' solution as this is a learning exercise more than anything else.
I have a GV & a FV both linked to same sqldatasource.
When a GV row is clicked, the FV becomes available for editing the row but the GV as a result is reduced to only that row. I want to GV to remain showing all rows. I am using GV selected_index event to invoke "SqlDataSource1.SelectCommand=
I am having issues with databinding a textbox within a tab within a gridview. The textbox displays the data information properly; however when I try to edit a row in my gridview anything I type within that textbox is not saved in the database. Also my other fields for my gridview are editable, I am only having issues with this textbox within a tab. Here is the code:
I was wondering what would be the best pratice to databind a gridview programmatically.Normally i put my databind code in the page_load() but is there a way to reduce the number of times the databind method is called?I mean... the page_load() method seem to be called a lots of times when doing callbacks with the grid.
im building a simple message messenger web application, i currently have a column in my database dedicated to the status of a message. Its bound to the third column in a datagrid.
After converting the column to a TemplateField and using a Label to fetch the data how do i change the text from the database to a small message, e.g. if the data in the database (as an interger) is 0. how do i change the interger to a string to display "UnRead". Do i need to do this during the databinding call or after the grid has been databound?
I know it would be easier to use a boolean and checkbox control but the interger column represents more values than true or false.
I have a gridview which I have databinded via the quick config facility, but I need to databind one column to a completely different sql table data field - how do I do this?
If I go into Gridview tasks and select the column and edit the data binding parameter but what is the format for a table outside the source definition for the the rest of the gridview?
I have a webForm which host a gridview and a formview. The formview is used for showing/editing a record which the user Select from the gridview.
In the formview Edit template I used DropDownList controls with
SelectedValue='<% bind("datafield")%>'
for enabling the user easier interface. A few of the DropDownList controls need to have a list of 100 items and I want to load the items from code behind and not from the aspx.
I tried to update the DDL's from FormView.Load, FormView.ModeChanging, FormView.PreRender but nothing I am getting an error like this:
[code]....
How do I load the DropDownList controls with items BEFORE the form databinding occurs.
I'm new to asp.net. I have a page with formview to read, edit and insert data to sql server 2008. On the page there are textboxes, dropdownlists. The Dropdownlist1 is bound to a lookup table. I also have a pop-up page to add, delete and update data underlying table. The problem is after i insert a new record to the lookup table and close the pop-up page, rebind the dropdownlist on the parent page. I'm refreshing the page with window.opener.location.href ....
but i want only the refresh the dropdownlist on the parent page.
I've got a class that implements IListSource and returns a generic List of ListItem objects (List<ListItem>). in this list one of the ListItems has the Selected attribute set to true.On the web page I have a standard asp:dropdownlist and I set it's datasource to the getList method of my class and databind it.The problem is that the databind seems to loose the selected Item and the first item in the generic list becomes selected.
i'm creating a webform with one gridview and three dropdownlist which are outside the gridview.In edit mode of the gridview i want to insert the values form the dropdownlist.what i select in dropdownlist it should be in gridview...i've three columns. so i've created three dropdownlist which are outside..i dont want the dropdown list in the gridview it should be separete .
have a dropdownlist (ddl2) which is dependent on the selected value of another dropdownlist (ddl1).I have set the appendatabounditems to "true" for ddl2 and have added a "Please Select" and a "Select All" options. The Options show in the list when the page first loads. When ddl1 is selected the page refreshes and ddl2 is populated, however the "Please Select" and "Select All" options have disappeared.
Basically when editing an item, I want to bind its ProviderId value to the DropDownList's select value.DropDownList is getting its list of values from other entity entity_List as you can see.
I have a datasource definded as a query to my database that has a column named "PrimaryUse". Sometimes there can be a value in the PrimaryUse column that isn't listed as one of the dropdownlist items and so my application crashes when trying to bind the dropdownlist's selectedvalue to that field. I'm trying to create code in the edititemtemplate's OnDataBinding event that will check if the value being returned from the datasource is a valid value listed as an item in the dropdownlist options. My problem is that I'm not sure how to get the datasources fieldvalue for that column in the behind code. Is this possible? Is so, can some one give me an example or point me in the direction on how to do this?So, in the OnDataBinding event for the edititemtemplate listed above, I would like to do the something like the following (psuedo code):
if datasource.datafieldvalue("PrimaryUse") is in dropdownlist.Items then Valid else set dropdownlist.Selectedvalue = "Default"
