And it actually seems to work on first instance (altho im not sure the above is a good way to do it, but the problem is when use the pagination on the gridview I get the error
Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
On the line
Dim productId As String = productListTable.DataKeys(i).Value
why I am getting this error and also is there a better way to do it ?
Using following method to create Shopping Cart Session [URL]Now running locally on my machine where sessionstate mode is inProc by default, all seems to perform fine.I'm writing an application which I've just placed up on hosting provider (shared hosting environment etc). Their default sessionstate is stateserver so I had to serialise the classes to fit in with this. It's using cookies.The basket (adding,removing etc) works fine but I'm seeing some odd things happen regarding the persistency of the session.
On my local machine, if I access the site in 2 separate browsers, if I add items in IE, I can see them in Firefox when I refresh. This doesn't make any sense to me since cookies are per browser.Plus I thought that when a session was generated, its id would be unique so there is no way that one user should be able to see anothers session data (unless tabbed in same browser perhaps)Even worse, if I start adding/removing items in IE and doing likewise in Firefox, both of them show very random cart results every time you refresh the browser.
The selecting products screen will look like a gridview which will display.
name price quantity Text Text Input box
So i.e. lets say I have 10 products per page so i.e. 10 quantity input boxes per gridview. And then I have 2 Buttons below my gridview i.e. Update and Checkout. Just even worrying about Update for now. How could that work i.e. would I have to check every input box in gridview for which a value was entered ?
I.e. is there any example how I can loop through gridview row check for a value which is greater than 0 or null for example and if there is a value then perform a function like [Code]
I am in the middle of building a very simple shopping cart in asp.net with a VB backend but I am running into problems with my code. When I run my application and try to add a product to the cart I get an error message.
Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
Line 27: Dim blnMatch As Boolean = False Line 28: Line 29: For Each Me.objDR In objDT.Rows Line 30: If objDR("StockItemName") = Product Then Line 31: objDR("Quantity") += txtQuantity.Text
I am not sure why it is doing this and was hoping that perhaps someone could take a look and offer up some advice? I have checked over my code and I cannot find anything wrong however I would take any guidence that you may have on it.
I am trying to create a shopping cart in Visual Basic. I have most of it figured out. However, when I click the Add Cart button, the item will add; however, when I add a new item, it will not go to the next line to display it. It instead replaces the first item I added. For example if the user chooses 1111 for the part number and qty is 2 then clicks the Add to Cart button, the following will show in a group box below: 1111 Alarm Clock 2 $19.95 $39.90
If the person wants to add part number 2222 and qty is 2, that relating info should show up below the first entry of the Alarm clock. In my code, it's not doing that, it's just replacing the first line (alarm clock entry). However, it is keeping track of the total amount added to the cart.
Here is my code that I have done for the Add Cart button:
Private Sub xAddButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles xAddButton.Click Dim searchFor As String
I've created a program that pulls item prices from a database. The problem I'm having right now is that I'd like to display a running total, as the program currently only displays the list of items and their prices.
Private Sub btnGoToCart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGoCart.Click Me.Hide()
I am working on a class project and I am trying to create a shopping cart application. I need to transfer info from listboxes on 2 forms to the main form and calculate the charges for "the books." I am having a hard time writing the code to properly transfer the items and I really have no idea where to start with the calculating the charges for subtotals of the selected books.
My project is to create a shopping cart application. I have my main form and from there the user can go to two different forms to add books to their cart, the cart being the main form. This all works. What I can't figure out, is how to use global variables for the prices, shipping, tax and updating the total. I have places for this information to show up on the main form, and I've created a module for the calculations and prices, but I don't know how to code it to get the prices to show up in the specified areas.
How can I get the items in my code from my listbox which is called "selectListBox" to a shopping cart called "cartlistbox", when the add button is clicked?
Public Class MainForm Private Sub MainForm_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Note: This code actually codes from a tutorial book I'm reading at the moment, so you can imagine this is frustrating me greatly! I'm building a basic shopping cart, using VB.NET 4, Visual Studio 2010 and MS SQL Server R2 2008. The code below is supposed to remove items from the cart, by reading a session variable, editing it to remove the appropriate ProductID and return the amending string to the session variable. It is then supposed to rebind the data to the gridview (gvCart) to refresh the data...but it seems here there is an error.
Every time I build the site in Visual Studio, it validates fine. But every time I run the site, and attempt to use the remove button it gives me the error:Incorrect syntax near ')'.ith the IDE pointing me toward the final parenthesis
Protected Sub gvCart_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles gvCart.SelectedIndexChanged 'This method is hooked to the Remove button & is removing items from the cart
i havent had problems in visual basic all the ay up to this point. I have been given a shopping cart program that I must use: a MainForm, MP3From, AlbumForm, and a module
I finally got my program to send data from the listbox on my MP3Form to the listbox on my MainForm but something isnt right still. I need to be able to click an an item from the lstMP3(listbox on MP3Form) to lstShoppingCart(listbox on MainForm) multiple times without having to close the MP3Form everytime to add the items to lstShoppingCart. Here is what I got so far on my MainForm: [code...]
This assignment makes me mad cause we have not even covered half the stuff I am having to use in this form at all this semester. If i can get a little explanation on instantiate, inheritance, and declaring and object variable and how its used to transfer data from one to the other.
I am working on a project for a class, and am having trouble getting my program to automatically calculate the subtotal every time an item is added to the shopping cart list. I've tried sub procedures and functions, but I can't seem to get it to work.
I have a gridview and use a session to pass the variables from the page to an edit page. This works perfectly, until you search for a number. When you search the correct record displays in gridview, but when you click edit, it passes the wrong record.
Private Sub gridview1_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles GridView1.RowEditing Session("wr_id") = GridView1.Rows(e.NewEditIndex).Cells(2).Text & "~/~" & _ GridView1.Rows(e.NewEditIndex).Cells(3).Text & "~/~" & _ GridView1.Rows(e.NewEditIndex).Cells(4).Text & "~/~" & _ [Code] .....
I realize not all of the code is pasted in here, because it would take too much space. Any Ideas? I'm guessing it has something to do with e.NewEditIndex
I am trying to make a webpage that has a list of items on 1 page which is displayed in a gridview that has the auto generate selected button enabled, they can click this button and it loads the item into a collection which i have stored in a session. On another page the session containing the items they selected gets displayed in a gridview. [code]...
have web page, In that I created table and loaded row values at run_time using javascriptNow I want to take a those table values in aspx.vb coding area, I tried it does not pull up my values even my table has 3 rows, but in aspx.vb area it shows row count as 0. How can I achieve this.
I have created a connection string, and i am populating a dropdownlist with an ID from a sql database.I want to be able to click on a ID from the dropdownlist and run a query to populate a gridview with data. I have made the dropdownlist autopostback = Enabled. I am not getting an error.
Here is my code:
Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlContracts.SelectedIndexChanged Dim ds As New DataSet
when I add a product to the shopping cart it adds it very well but the problem is in the session, it stores it in the server not in the client browser.
so if some body visit the website from another computer he can see the added products on his browser while it should be empty.
Is there a way to save it on the client side instead of the server side ??
I want to populate a checkbox field in a gridview.
I am using the Checked='<%# Convert.ToBoolean(Eval("Inactive")) %>' statement but the issue that I am facing is that in the database some records contain NULL for Inactive. If it encounters a 0 or 1 value it works fine but if NULL it throws an exception.
Kindly guide me how to populate the checkbox so that it should be unchecked even if the field is null.
I'd like to have a backgroundworker process data that will eventually populate a gridview in my windows form. I need to use a backgroundworker because the process takes a little while, normally causing the program to slow/freeze until it's opening and streaming connections.. So, I'm using a background worker to perform these methods.How can I take the data from the background worker (on a separate thread than the UI) and use it to populate controls in the UI?
It has been so long since I have coded a page in VB. For the life of me I just cannot remember how to do this. I have a GridView on an ASP page. Each row has a comment ImageButton. I already have the gridview and text box wrapped in a UpdatePanel. The gridview shows all of the correct information. I just need to add some code to populate the text box with the comment when a user clicks on that row's ImageButton.
The comments are stored in SQL 2005 DB if that makes a difference. Should I shove the comments inside a hidden field of the gridview or is there a function that will allow me to query the db for that specific comment. End goal would be to not refresh the page if possible.
If I used a generic list Class to hold data objects that I am pulling from SQL Server using Linq to sql to populate a datagridview would I need to make any modifications to the datagridview control to accomodate multiple columns or would I need to make any modifications to the generic list class to accomodate the multiple columns in a row that is typical of a record in SQL Server? And one more thing which I believe is the easy part. To bind the list to a datagrid view would I just use the datasource property of the datagridview control.
I am using a gridview in my form.aspx page. The textboxes in each row of the gridview are to be populated from a datagrid upon clicking a particular field of the datagrid
All of the columns populate correctly except for the Long column. It returns a null for all rows. I have tested the SQL statement in Toad and it works perfectly. how to get an Oracle Long data type to populate in a gridview? This is driving me nuts
I have to set GridView.DataKeyNames(This is really a question about the syntax for a string array, in VB.Net.)I am discovering the PrimaryKey columns names from within a loop, ie:For Each fld As IEntityField In Me.llbDataSource.EntityCollection(0).PrimaryKeyFields'fld.Name ' this is where the column name is stored, so I have to get this into an array Next..[code]So, basically, how does one declare a string array (as required by GridView.DataKeyNames), and then populate the elements of the array from within a loop?
populate values from a database(Access) in to vb.net form. after selecting a field from first form , the next form should display all the parameters used in the selected field from the data base. Also if do editing it shppuld be updated in the database.
Public Class Editdetails Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim cn As New System.Data.OleDb.OleDbConnection[code]....
I have an application where a user is entering data into textfields using vb.net and then it is saving to excel. The textfields only accept numbers and do not allow the user to proceed unless all textfields have been filled out. If for some reason the user cannot enter in data (machine being broken etc...) is there a way that a messgagebox with a textfield can pop up allowing them to enter the reason that they couldn't enter a reading and then get saved to a textfile or sent as an email.
I am storing a session variable that a user types into a textbox. With their valid input, their session gets created and they get a little more functionality than the regular end users of the site.I was wondering if it is possible to find a way to add someone's session variable to the end of a URL. This way we can email a link to one of our clients, they click it, and their session has automatically begun. They already have the textbox to enter their code into, but I was told that it would be much easier for the users to just click a link that will start their session.
