Asp.net - Dynamically Add Drop Down Lists And Remember Them Through Postbacks?
Aug 10, 2009
I need to show a drop down list when the page loads, the default selected value is nothing, or an empty element (such as "-"). When the user selects one value from the list, another drop down list is added below the first one, and so on.My problem with this is how you make the page to remember the drop down lists created through postbacks and the values they have selected?
EDIT: I did this example for dynamically add drop down lists and suscribe them to an event handler but the event won't fire.
EDIT 2: Changed the code because I labelled for VB.Net and posted something in C#. I update the code with some trivial improvements, but still won't fire the event :(
Private myDdlArray As New List(Of DropDownList)
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If (Session("ddl") Is Nothing) Then
I have an asp.net page within which I've used several AJAX controls doing partial postbacks with update panels. In testing it works wonderfully, all of the postbacks are done without reloading the page and it makes the whole process smooth. I uploaded this to the web server for some outside testing and all of the tested reported that the page was reloading a lot. I tried it within the network from the web server and it was still working fine. However, when I tried it from outside the network at home, it does in fact appear to be doing full postbacks whenever it's set to do partial postbacks for these update panels.
I can't seem to find out why this is happening. Even with the increased time it takes to communicate with the server, it shouldn't reload the page - it should just, at most, stall for a moment. Another strange thing is that it's not maintaining the scroll position even though I have it set to do so for the one or two full postbacks I have. It reloads to the top of the page.
I'm thinking perhaps this may be something set on the server, but I can't be sure.
i have two pages.1.aspx and 2.aspx i have a drop down list on the first page and a back and sumbit button on the second page..If i make a selection in the drop down list and go the second page and then go the the first page again with the back button. the drop down list doesnt show the selection that i did.i tried the use "sessions" but didnt work, also tried postback but no luck. I read something about "Enableviewstate" also no luck.[code]
I am fairly new to VB (have done some VB in excell, but its a bit different)
I have a couple of questions:
1) How do I populate a dropdown list from a Database Row 2?
2) When I create a Database from Acess, where do I save the database? and If I build the exe program later on, will it include the database, or how does it work? I feel completely stupid, but one of the best ways to learn is to try over and over again
I'll try to clarify by using the following example. In here I have two Drop down lists (ddlInsertEmployee + ddlInsertCustomer) which should both be bound to fetch data from tables [Employee.EmployeeID] and [Customer.CustomerID] and insert it into table [Task].
The problem is that it inserts data from Employee.Fullname and Customer.Fullname into resp.Employee.EmployeeID and Customer. CustomerID.If I would change the Drop down lists to textboxes, and manually insert the IDs, it works like a charm, but this is not very efficient, I want to be able to see the entire Fullname.how to change my Sqlstring in order to make this work correctly.
Imports System Imports System.Collections.Generic Imports System.Data[code].......
I'm using Visual Studio for the first time and VB. I have programed for awhile, but mostly new to windows related softwares. I have an access database connected to my test application and I am trying to display a drop down box with a listing of the item names in my table and the value that is sent off to my database is the actual item id. I can figure out the database part in terms of adding and editing, but I haven't been able to figure out how to display the full list. If I click the next button the list that is generated it displays the next item, but I would rather just list all items in the drop down box and remove that toolbar all together.
Here is my drop down list and data source. My question is.. when is it possible to set a defaulted selected option for the drop down list, aka when have all the dropdownlists been databound and their ListItems populated? I have tried Page_PreRender, age_PreRenderComplete, Page_Load.I have read over MSDN's Page Life cycle event which suggest Page_PreRender.
I have a couple drop down lists connecting to an Access database. I can get the first drop down list to populate with the departments I have listed under "dept" in my access file. After someone selected a "dept" i want the second drop down list to populate with the names ("name"). Right now the second dropdown list is showing up but isn't poplulating. What am I doing wrong?!? I would like to include a third dropdown list for another selection with a button to then show things from the specific selections. Right now, I just need to figure out how to populate a list upon another lists' selections.
ok, I'm basically trying to make mulitple drop down lists on my form. When the page loads, I can get my main dropdown list, called makelist, to fill in with the items that I want from a txt file.
What I'm trying to do is whenever the selectedindex is changed in makelist, it has to load a different dropdown list, called modellist with items from a different txt file.
I've written a program to work out the flight distance between a set of seven cities around the world using a 2D array but was wondering how I would if possible go about having the values for each city selected via two drop down lists (say start city and destination city).
Public Class frmDistance Private Sub Flightdist_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim rowcolumn(7, 7) As Integer Dim sr As IO.StreamReader = IO.File.OpenText("Distance1.Txt")
I have to retrieve same amount of datas from a variable number of clients in an arraylist. I know I can put arraylists in arraylists but would be easier to get one arraylist for each client dynamically declared.
Ex: alClients (XXX, YYY, ZZZ) for i as integer = 0 to clientsNumber -1 Dim nameVariable = "al"+ alClients(i) ' = alXXX Dim nameVariable as New arraylist() ... Next
But it seems not to be possible to do that so is there a way to do it? By surcharging constructor of the Class New ArrayList(), ok but how??
I have two list boxes. A users selects a value from each, clicks a button and the application creates a relationship between the two selected items by saving them in an array and displaying the relationship in a third list box.
What I want to allow is for users to be able to drag a value from one list box and drop it on top of another value. I have the code to capture the value of the item dragged but I don't see how to capture the item that the data is dropped onto.
Is there a way to capture the targeted selected item?
I've got a couple of drop down lists for languages. I bind them to a language list that comes from a query. Then the fields are also bound to the row in the DB they relate to. I have several panels with the language drop down - each "tied" to a different table in my DB. When I call up different records on the same panel the drop downs immediately "set to the position" of that rows language in the list. But when I call up another panel - tied to another database table - I see that language in the drop down.
I'm using vb.net. Basically, I have a drop down list, text box and a submit button. You choose a movie director from a drop down list, then type in a movie, click button and it adds the data to my database.There's another button which hides/shows drop down list, text box and submit button using Visible = True and Visible = False, but what I don't like about it is when it hides the things I said before, it leaves some white/empty space like if they are still there, but not visible.Is there anyway to put some kind of holder/container and place a button which when clicked could add my drop down list, text box and submit buttons to that place?
I have a gridview which can be filtered from one or more values in a querystring. That all works great: e.g. "?subject=Maths&authorName=Bond_James&type=Magazine" The values passed to the query string come from 3 drop down lists: Subject, Author, Type.What I'd like is when the user presses "Filter" it will take the selected values from the drop down lists and pass them to the querystring - it could be 1 value, 2, or all 3 (like above).
The drop down lists have an item called "All Subjects" / "All Author" / "All Type" each with a value of -1. The idea being that if the user leaves these items selected then the Filter button just ignores them.
Here is my code so far:
Protected Sub buttonFilterGo_Click(ByVal sender As Object, ByVal e As EventArgs) Handles buttonFilterGo.Click Dim queryString As String Dim selectedAuthorString As String = "author=" & dropAuthorList.SelectedItem.Value
[code]....
Also, one more thing. How do I get the drop down lists to have the filters selected when the page re loads?
EDIT: I changed the default values of the drop down lists to "" - this leaves the URL looking messy though ?author=&subject=&type= This works, is it the best way?
I have four drop down lists here and I've assigned the datasource and displaymemberproperties so they are populated by a table. When I run the program and select a choice, all four of them get updated with the new choice.
I want to create a website where it is possible to add dynamically "X" dropdown-lists (or other elements)These dropdown-lists should be shown on the website and furthermore there should be an other element be shown, that depends on the dropdown-list (for example: if the user chooses option "A" there is a checkbox, if the user chooses "B" there is a input field)
I have a website where the user requires to add and remove Headlines from the main page. The headlines are stored in a database with a column titled 'Display' (true or false) which decides if the headlines appear. I want the user to have the ability to add or remove headlines from the main page, so have created another page which creates a table of all headlines along with a drop down list containing 'Enable' and 'disable'. I want these drop down lists to work by when the user changes the value in the drop down list the database will be updated. Only I cant find how to give the drop down lists an on change event.
Our solution is built on ASP.NET v1.1 framework. User is presented with login form, so upon providing credentials this information is posted back to the server. Upon postback SessionID changes and our application crashes as some information which is required for processing is stored in the cache and is identified by SessionID string as a part of the name.
This SessionID change happens absolutely randomly and only to some of the clients. Most of the time browser used to view the page and post info is IE8. I cannot reproduce this issue in our test environment, as SessionID is persistent though-out the whole testing process.
I've already checked all solutions, i.e.
Session cache is used on Page_Load to retrieve/store some information, so it's initialized and contains data stored. I've made a Health Monitoring check on Application_End event to capture any possible AppDomain crashes using Reflection and Diagnostics Libraries and retrieving ShutDownMessage from httpruntime object, but that's also not a case. Cookieless attribute of the sessionState in web.config is set to false (using URL to store SessionID is not an option)
All MS security and bug fixes are installed on the server. IIS Server settings are similar to the ones we use in Test Environment.
Alright, so here's my basic ASP.NET page setup: I've got a page with a GridView that has ContentTemplates in it. You can add a row and edit/remove rows at any time. There's a "New" button that creates a new row.
All of this data is bound to custom data objects. So if I have a GridView of "People" and each row has "FirstName", "LastName", and "Gender" (with TextBox and DropDown controls), I then have a "Person" object which has public properties for "FirstName", "LastName", etc. I have the binding set up correctly, and I can push data into the GridView from the object, and I persist the object with the Session variable. My page lifetime structure looks something like this:
Page_Load: Loads the List(Of Person) from Session() Any events fire, and modify the List(Of Person).
After any event, the List(Of Person) gets saved back into Session(), and is then DataBound to the GridView (and any subsequent fields are also DataBound, such as the DropDownList.
My question is: Whenever I fill in rows in the GridView, and then add a new row (there is no database saving going on whatsoever), my fields clear out and don't persist across PostBacks. So, how can I persist my custom data objects with databinding across postbacks?
I have two lists. One list is a list of names, the other list is a list of how many times each name is found in the first list noted in the database
so... Nick John Jim Jack
is the firs tlist
10 13 13 2
is the second list. Nick had 10, john 13 and so on.I want to sort the second list from large to small, but have the index for the first list still linked to the correct amount of calls.i do it this way so I can
for x = 0 to num_of_names string = lst_name(x) & "-" & lst_count(x) next x
I have an ASP.NET form that the user can make lots of changes to, each time they make a change the page PostsBack and the details are updated.If the user hits the browser back button they go back through all the previous versions of the page.Is it possible to stop each PostBack being treated by the browser as a new page?
I am settting up control propertis on page load. Like visiblilty of control depending on loaded data. And very simple setting up images to button controls. For page load it works fine but on postback these values are not set back. This is my code. When it's a postback btnSecurityQA image is missing and visibility of all following controls is not set accordingly.
If Not IsPostBack Then ButtonImage.SetPath(btnSecurityQA, GetLocalResourceObject(btnSecurityQA.ID & "BaseName").ToString())
In VS2010 I have VB.NET codebehind aspx pages and I'm using Ajax multihandleslider extensions to filter search results on numerical values.
Fistly, the multihandle sliders don't display in the designer... I have to remove the slider targets tag:
In order to make it display in the designer... this isn't so much a big issue but an annoyance.
I am displaying items in a given category. So I get the max and min prices for all items in that category and assign the sliderextension max/min values appropriately.
This works fine until... I change the item category and go get a new max/min value for the slider control. I set the max/min values, then I set the target textbox values each to the corresponding max/min values.
The slider handles don't repaint (or init?) properly Like say for example my initial min/max is 1/100 if I do a full postback and change the max value to 1000 then the slider bar (correctly) stays the same size but the handle appears WAYYYY to the right off the page and I have to scroll to it. When I click it, it shoots back onto the slider bar.
I know how to check whether an item exists in a list using (MyList.Contains), But I do not know how to check the whole list. For example (use one button and one richtextbox):
I'm using RichTextFormat, and i'm using cf to change the color of strings. I have this
Code: cf22dgreengiant
Its actually like this though
Code: cf2 2dgreengiant
But the parser thinks that the 2 in his name is part of cf. There's a character, in many different formats (usually ) that will fix it, but I can't remember what those characters are called so I can't look it up. It would be like this, assuming ! was the character. This would make it parse correctly
Code: cf2!2dgreengiant
So what is that character called? Sorry for the dumb question, but I can't for the life of me remember.
How can i get my program to remember settings?I have made it so that they click on a register button, if they enter the correct registration code, it will unlock these features. How can i make it so it remembers that the key has been inserted, so when the user next uses the program, they dont have to re enter the key. I think it has something to do with ini files, but im not sure how i can implement it.Here is the
Private Sub Register_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Register.Click If UserID.Text * (KeyID.Text / 2654) > "2234047144494" And UserID.Text * (KeyID.Text / 994) < "213725721516" Then MsgBox("The User ID and Key are Correct! Registration is now complete. You now have full access to EVERY feature.
