Web Forms :: Getting A Dropdownlist Populated When Binding To Datatable
Aug 10, 2010
I have 2 dropdown lists on a WebForm. One of them is populated in the page's Page_Load event. This oneworks fine with the following code.
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Then, after a value is selected from this list and a date is selected from a DateTime picker, then I click a button which is supposed to populate the 2nd dropdownlist. In the debugger in the button's click event I can see that the dataset is being populated with data, but then the list is never populated after the DataBind() method is run. Here is code from the button's click event.
i have one simple question; do I have to... or is there any need to validate value from DropDownLists that are populated from SQL Datatables. I know how to validate them, but I am just concerned about potential SQL Injection, because those DropDownLists are going to be "Input fields" for a new Datatable, and insted of using TextBoxes, user will choose values from those DDL's and Submit them (INSERT INTO) to SQL Datatable. Is there a way for a "hacker" to insert his item value into DropDownList. I hop You understand what I mean!?
I have a DropDownList populated with a SQL Stored Procedure. On the page, there is also a button that when pressed, processes the contents of the dropdownlist. I would then like the dropdownlist to automatically remove the selection, and if there is nothing left in the dropdownlist, I would also like the button to be disabled.
I have two drop down lists on my page. One (DropDownList A) has the values preset by me. The other (DropDownList B) has its values filled by a database query if a button is pressed. Each of them have AutoPostBack set to true. Each of them have corresponding onselectedindexchanged functions. DropDownList A works fine. When I change it, I want it to turn itself invisible. It does. DropwDownList B is not working. When I select something, it does the postback but the selected item is reset and the onselectedindexchanged function is never called. I feel like this is a problem I've solved in the past, but it's been 3 years since I programmed ASP.NET. All this is done in C# by the way.
i am currently working on a webform that has several dynamically populated dropdown lists. this works just fine, however, i have other web controls that require to have a postback..and at the time the page postsback, it reloads my dropdownlists, reseting whatever option i had chosen...
Item Selected in MediaTypeDDL determines values in MediaFormatDDL. I'm using Javascript to populate MediaFormatDDL. This is working. I now select the item I want from MediaFormatDDL. That works The problem I'm seeing occurs when I press the button to save the values from the screen. I don't see the Item I selected from MediaTypeDDL. All the other fields are okay. This must be someThing simple, but I'm not seeing it.
I have a dynamic dropdown that is populated from sql. The user is supposed to select an option from the dropdown, then click a search button on the form to return some results based on that selection. It works fine if the dropdown gets populated with more than one record. However, if only one record is returned, that one record can't be selected. Whether you select it or just leave it alone since it's the only one, when you click the form button (search button), no results are returned b/c the dropdown selection must not be actually selected.
I've included the relevant code below. First the DDL, then the datasource, and finally the C# code in the if (!Page.IsPostBack)
I have a gridview which contains a templatefield. Inside this is an ImageButton and a dropdownlist. This is all created in the aspx page, although the ddl list items are populated in the RowDataBound event in the vb page. When i change the selected item in the drop down list and hit the imagebutton, the selected item is not maintained after postback. Instead the first record is displayed in the dropdownlist. I have wrapped an If Not Page.IsPostback around the datasource and databind's but this doesn't help. I have tried enabling viewstate in all areas on the page too, but still nothing. The list items for the ddl must be created on RowDataBound also. As far as I am aware, my ddl is not really dynamic, its just the list items which I add in the code behind which are classed as dynamic.
I am trying to add many rows in the gridview by clicking a Add button in web form by takeing the value from the textbox then add it to gridview but i couldn't because it accept one row only so how can I let the gridview accept more than one row in every click to the button.
I have a function that constructs a datatable from a file that the client uploads. And I want to bind that datatable to a listview but I'm not sure what I'm doing wrong... Say, the datatable is like:
FirstName LastName John Smith
Here's how my aspx looks like:
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In my names.aspx.cs file, I do: lvNames.Datasource = dt; //dt is a datatable lvNames.DataBind();
When I run my aspx page, the listview is empty, is there something obvious I'm doing wrong?
I have a gridview with empty data template. In this empty data template i have a table(HTML) with 4 columns. When user enters data i want to save this in a datatable temporarily at a button click event.. Again if user wants to add one more rows data that also should be added to the same table where i added previous row data. So now the datatable has 2 rows. Like this he may add any no of rows. What i want is all the rows should be displayed when i bind datatable to gridview..At the click event i am adding 1 row at a time to the datatable
I have a DevExpress WebChart Control that binds to a DataTable. The chart control renders fine from the DataTable until I try to import data from a details view(i think the chart control renders before the detailsview?).
Here is three renderings.
Chart 1. just rendering from the datatable
Chart 2 The sqldatasource gets its para. from the values of two label controls to render the detailsview. The detailsview renders fine
Chart 3, the problem comes in when I try to extract the values from the DetailsView to populate the Chart, I loose the value. I am assuming the the datatable is built before the rendering of the detailsview? Lost at this point.
I need to populate a dropdownlist with results from a linq query done in my controller. I want users to be displayed but when the item is selected and submitted, the userid is passed back to the controller.my controller:
I'm populating a DropDownList using JS on the client and validating with a RequiredFieldValidator.This works fine on the client but the Page.IsValid consistently comes back false on the server.Is this because the selected value wasn't in the DropDownList when it was first served to the page?What's the easiest way around this? (I need to leave server validation turned on)
When I use the code below an error accur when click add button to insert into sql because the selected value in DropDownList is back to --select-- Idon't know why it should be the the value I selectedbut when not use this code and bind the DropDownList using wizard it works but I need to use the code to make the first selection is --select--.
private void PopulateDropDownList() { string constr = ConfigurationManager.ConnectionStrings[1].ConnectionString; using (SqlConnection con = new SqlConnection(constr)) { using (SqlCommand cmd = new SqlCommand("SELECT Country_ID,Country_Name FROM Country", con)) { using (SqlDataAdapter da = new SqlDataAdapter(cmd)) {
My issue is similar to [URL] how-to-use-the-value-of-a-selected-value-from-a-dropdownlist-populated-with-ajax but I am using ASP.NET, not PHP. I have a dropdownlist that is populated by another dropdownlist's current value through ajax. So if DDL A is 'NY', DDL B is populated with different data relating to 'NY'. I need that data to be posted back to the server because this affects an SQLDataSource parameter. However, as far as I can tell, the value is always null after postback resulting in the gridview to be empty.
Okay, here's something that I could easily do the hard way and manually wire up each form element and save it to a datatable in memory, but there has to be a more efficient way to do it.
Here's what I have:
1. A strongly typed datatable and tableadapter in a XSD name Orders
2. A formview control which currently is connected to an ODS connected to the Orders tableadapter, this makes it easy to wire up the databindings for each form field in design view
I would like to:
- bind the the formview to an instance of the strongly typed datatable, and then save the dt to a session object without interacting with the actual database
- load forms on subsequent pages from the dt in session
- ultimately save the dt info to an actual database table on the third page
I've read some solutions where a custom class is created, but to me this seems like almost as much work as wiring up the form field to the table columns manually in code.
I have no clue what I'm doing wrong here, but I wanted to create a grid view based on a return from a tableadapter.
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Also, maybe I should be going about this another way as I wanted to add a drop down to each record and a link to each record.On pointers on how I should do this would be great too.
