I am programing a basic P.O.S. (Point of Sale) system, ad am looking for the best way to save Inventory objects. The object contains a few Singles and Strings (Such as barcode, name, price...ect). Assuming the user could possibly input thousands of such items, what is the best way to store and handle these?
My first, and simplest thought, is to add each inventory Item to an ArrayList, then once the user saves, or closes, the ArrayList prints each object to a text file, then when the program opens it reads the text file to re-populate the Array list. However, this seems very un-efficient (I assume). Would it be better to use an excell file or a Database (I know almost nothing about databases, but I can learn), or something completely different?
How can I add and save items to a List of Items in a listbox to an existing Text File in the bin folder? I'm already using IOStreamReader to pull information from the file, but I want the user to be able to add additional items (Name and Last name). Also, I'm having some issues organizing the list in the list box.How can I organize it pro pertly (2 columns)
In .NET, the Generics Lists have a sort function that accepts IComparer or Comparison. I'd like to sort just part of a list. Hopefully I can specify the start index, count of elements to sort, and a lambda function. It looks like you can only use lambda functions to do this if you're sorting the entire list. Is that right or did I miss something?
I am using file.readalllines to read the file into a string, then using listbox.items.addrange and splitting by vbcrlf to insert the items. Is there a way to reduce the lag it causes for loading huge lists?
How can I save ALL of the items in a listview, items that were added by the user? I tried application Settings and tried creating a settings file but there is not a settings option for listview items.
I have researched the net, youtube, and the msdn DB, and still can not find the working answer I am looking for. I would like someone to show me how you would save the contents of "Listbox1" to a .txt file using the "Save As" Option. I know how to hardcode a savepoint in, but since there will be multiple users I would like the option to be up to the end-user.
I'm looping all the properties in an object via reflection:
For Each p As PropertyInfo In values.[GetType]().GetProperties() If p.CanRead Then 'Do stuff End If Next
how to determine whether the property in question is a generic List(Of T)? If it is I need to loop the list itself.
I've experimented with GetType and TypeOf but have not managed to get anything working.
To clarify, I want to keep this generic. I do not want to specify the type of T, I need to loop the list items and call the ToString method on each item. T could be one of a number of different types (application specific reference types). Is it possible to do this without specifying types?
This program is supposed to allow the user to check items in a checked list box. If the item is checked, it goes into the Completed List Box on the right. The program then adds the unchecked items to the Pending list box on the left. I keep getting placement values (e.g. O,1,2) instead of the strings (e.g. "Key Returned") in the list box results (see photo attached)
Public Class frmCheckOut Dim i As Integer Dim cleaning As String = "Cleaning Inspection" Dim damage As String = "Damage Repaired"
Another program I am working on for fun, I am basically shuffling a list inside a listbox, what I want to do is delete the rest but not sure how to go through with that. At the moment I have this: [code] Just contains the code, declarations outside weren't included.So anyway, once clicked, it will call on the function to basically shuffle in a for loop, I was wondering if I should (or how should) create another function and call it in the click button or have just a loop in the click button so it deletes half the list. What I am doing is I have 20 list of items, I want the program to shuffle the items and then deleting the lower 10, meaning, if I had 10 items and wanted 5 top, I'd want: 0, 1, 2, 3, 4 and deleting 5, 6, 7, 8, 9.
I am attempting to read the results from a SQL query into a List(Of) and I can see the List.count while adding items to the List increments, however in another part of my code when I am attempting to read the List the List.Count returns 0. My List is as follows:
I have an error panel that is subbed in to a page if an error goes wrong to gracefully handle and display errors.Currently, I am just appending the error messages to a string and pushing that to a label. If you have multiple errors, this gets messy.I'd like to push each error to a list item in a bulleted, unordered list.How can I dynamically generate, from a vb codebehind file, new list items inside of an undordered list element?
I have two generic lists, named ListA and ListB. Both ListA and ListB could potentially have duplicate items. What I would like to do is use LINQ to grab the items in ListB that are not in ListA, but I'm unsure how to do so.
i want to search item A (from a list of X items) in list B but i want to get the item not found example Search ITEM A in LIST B if not found then return a print....if found continue with ITEM B..and so on.
That was probably bad title, but I'll illustrate what I'm trying to do. I have a method in a class that I need to call several times. The method returns a List(Of String). I'm just grabbing some information from a database.
VB.NET Public Function GetTestList() As List(Of String) Dim int As Integer = 0
I have a List(Of MyObj), and I want to iterate through that list and compare each element to all other elements in the same list, excluding (if possible) the same element. I have a solution that works, but it's slow and uses double For loops. It may possibly have also summoned Cthulhu from his sleep. This below is a sanitized version of what I have:
Dim MyList As New List(Of MyObj)({Obj1, Obj2, Obj3, Obj4, Obj5, Obj6}) If MyList.Count > 0 Then For i = 0 To (MyList.Count - 1) Step 1
I want to know how to test the 1st list box if it has items more than the other list box but by one item, here is what i have: If lstInvisibleTv. Items.Count > lstInvisiblePc.Items.Count Then it works good if the lstInvisibleTv list box is greater than the other list box by one but it also works if it is greater the other one by one or more which I do not want. I want it to work just by one.
I'm trying to get this code to save the list when a new website is added, how do I get a list of collections to save a link that I designate into the list?
Private Sub ToolStripButton8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton8.Click ToolStripComboBox2.Items.Add(WebBrowser1.Url)
I have a program that will compare an array of grocery list items glist and an array of coupon item clist.When I compare the two and if there is a match somewhere in the array I want to have a picturebox visible.When there is no match, I want the picture box not to be visible. [code] The code seems to work great until I come to the else statement.When the code finds a match it displays the picture box and the msgbox without error, but as soon as the message box is cleared, even though i've input it as an ELSE statement, the picturebox goes false again.Does anyone have any idea of how I can "hold" the picturebox to stay visible while the match between the arrays exists?
i am writing a program that reads a excel report from accounting software with our weeks orders on... so basically the program reads a list of around 100 items which all works fine.I also have a database that holds info on each item, when the excel sheet is parsed the software checks to see if any new items have been added to the list that are not on the softwares database. this is where i am having the issue.I have two lists: ItemsOrdered & ExistsingItems.
All the items ordered this week are in ItemsOrdered and all the items not in the items in the database are in the ExistsingItems list. using these two lists how can i find items that are in ItemsOrdered but not in ExistsingItems.
I have a List object and I want to remove the duplicated items but leaving at least one of the duplicated items in the list;I wrote something like this however I would optimize this code for better performance, is there something faster?
Const chars As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" Dim rnd As New Random() Dim mylist As List(Of String) = Enumerable.Range(1, 100).Select(Function(i)
I have been writing code fore a rather large project in the past mounts And Im beginning to think about arcitecture of the program... Its just a complete mess. I dont know how to tackle so much code..Its beginning to be impossible to debug.Basically Im doing the following prosidures. Importing several a Excel files and getting the rfrequency data from these files..Displaying them in a litview and a datatable... so you are able to edit them..Doing some calculation and exporting the results back to a xls file.Problem is now that im going to add more functionallity to the program,. What im woundering about is, is there some good unofficial guides on how to program with OOP?
I've been messing around with prime numbers for a while now, but I now want to use massive numbers, say a few million digits in length. Is there a way of storing and performing mathematical functions with such large numbers? Is it even possible on my home computer? I read on another old thread, something about a big number library, but the links he gave are now dead.
I have a combo box in my vb.net webbrowser when during a particular session the cobo box displays the all pages visited when the form is closed all vanishes[code]...
I have a form with a listbox. I'm trying to save the items that I add in the listbox to a file that i create when I use the save dialog. Every time I run this and try to save the file with all the listbox items, I get an error from VB that says "Procedure call or argument is not valid."[code]...
My download manager records the history of your downloads, The problem is that I can't seem to find a code to save the Items in that combo box in a txt file.
