in my project I insert values into a database, each value needs to be unique, currently I am using the following code to check for the value in the database before inserting, if it exists I loop back and generate another value and check again..
Dim SerialCount As Integer
SerialCount = 0
Dim con As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:UsersMatt-ASUSDocuments im_db.accdb;Persist Security Info=False")
I have a listbox control that has a selection mode "MultiSimple" (I've also tried MultiExtended). I also have a button that uses this code to select all the items in the list:
Dim i As Integer For i = 0 To ListBox1.Items.Count - 1 ListBox1.SetSelected(i, True) Next i
It works ok but the problem is that it's very slow. I have cases where there are 60 000 items in the listbox, and it takes forever to select them all. Is there any function that would select all at once (Just like ListBox1.ClearSelected() unselects all instantly)?
I am working on process for validating documents to make sure that they meet corporate standards. One of the steps is to make sure that the Word document does not use non-approved fonts.I have the following stub of code, which works:
Dim wordApplication As Word.ApplicationClass = New Word.ApplicationClass() Dim wordDocument As Word.Document = Nothing Dim fontList As New List(Of String)()
I have a simple multithread application that stores updated data from a list of websites. After each thread gathers data, it then store the data into the same text file. I am now thinking of having each thread store the data directly into a arrayList, and after a certain amount of time past, store from the arrayList to the text file. Which situation would enable the application to complete its task faster?
I'm converting a process from VB 6.0 to VB .Net. The process copies a table from one database table to another database. In many cases they are not linked so a "Select * into Table2 from Table1" is not a solution. Also the source table may be a temporary global table that has a unique structure. The current process reads the source table into an ADODB recordset, obtains the columns attributes to create a new table, creates the new table, builds insert statements from the source table, and then inserts the rows into the new table. I'd like to take advantage of any .Net features that may be more efficient than that. Can anyone point me in the right Direction?
I'm using ADO.Net to work with an Excel Document. Essentially, I'm looking up values in a table called "source" and creating a new table called "result" which will be populated with the results of my query.
I have a couple of questions.A) How can I check if a table exists and create a new one if it doesn't? B) Is a table the same as a sheet in Excel?[URL]...
I'm trying to check username and password by using a For Each Statement. If it validates then messagebox saying welcome appears, if it doesn't a message box saying "incorrect" will keep popping up over and over until it's done looping through the table. How can i correct this and just make it display one time. Also when it does validate a new window will show up with users First and Last name in a textbox, How can I edit users info and then save to db.
Private Sub Button1_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles Button1.Click Dim data As New datalinq1DataContext
I need to check if a Commodity entered into (TextBox1.Text) already exists on my table before i insert it. I'm having issues checking if the number of rows returned from my Select is equal 0? Also i'm wondering should i be checking for an exception and open/closing my connections each time i make a call to my DB or is the way i have it coded below OK?
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click Try myConnection = New SqlConnection("server=localSQLEXPRESS;uid=sa;password=12345;database=My DB") myConnection.Open()
I have a IF statement which is checking each row in the data table (for a match) and ELSE statement with commands which are executed if the If statement is not satisfied. Now I would like to write like so that it goes to the Else part BUT ONLY for values which are not satisfied in the IF statement. If I am more specific; I would like to calculate values if a match is found and just print them if it is not fond (usually there are both cases). Now the problem is the bold text; if there is a match found I don't want it processed BUT if the match is found I do. How can I write that?
currencyPosition = 0 Dim d As Integer = w + 100 For Each currency In Ary
i need to create a hash table using a multiplication method and i need to create an array of linked listso how i can to create array of linkedlist in vb or c# ?
I'm trying to retrieve values from a look up table with the selectedRows method. But i'm getting the exception InvalidCast. It says: Conversion from string "Codigo" to type'Integer' is not valid. Well my code is varchar not numeric.
Try frmMovimientos.codDestino = dgLook.SelectedRows("Codigo").ToString frmMovimientos.desDestino = dgLook.SelectedRows("Descripcion").ToString Catch ex As Exception[code]....
I have a project in VB2010 it is well connected to the database (DB.accdb) access2007. I'm trying to save the photo into the database table using Binary method. I am successfully able to (Save, Search). my problem is in the EDIT button : I'm supposed to search first to return\display the info+Photo on the form controls (Textbox + PictureBox), now i want to do EDIT, i use sql string : SqlStr = "Update MyTable Set Field1 = '" & Text1.Text & "', PhotoOle = [b]????[/b]"
I'm not able to convert the PictureBox That contains the returned photo to Byes() using : ImageBytes = Ctype(PictureBox1.Image, Byte()) .... not working . -Or- ImageBytes = Ctype(DaraRead!PhotoOle, Byte()) .... not working either.
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
Let say I have a function inside a class which require 4 parameter (table name,field name,field value, return field) When I use this function my form, such as
myclass.Search("customers", <-- after pressing the "," a popup list will be displayed that contain all the fields in "customers" table.
I created a new query in the dataset designer. There are now 2 queries there. The original one and the new one.I also added named parameters in the Where clause of the 2nd query.This is the query in the new one:
You'd think both are the same. But maybe it's the compiler that Microsoft has used, but I've noticed that when compiling two very small programs, identical logic. VB.NET uses more IL instructions.Is it true than that c# must be faster, if only because its compiler is smarter.
A long time a agp I settled into a listview as an indicating device. I do not use pictorial modes or graphics. Just listing and multicolumn listing.I am also a performance bug and I have written realtime monitors for monitoring cpu activity in real-time and normally rum them starting at bootime. Lately I have found that the listview throws away time. In a tight loop, the list view does not take all cpu time available and the listview is relatively slow.
Does anyone know of a control like the list views only it's faster? Multi-colored and multi-columned are musts.
I have a simple application, a form with two datepicker( Datepicker1 is for startsearchdate, while datepicker2 is endsearchdate) to filter out any record that not in the range. The source of the record is readed from a rtf file.The record is in format as showm below.[code]...
My co-worker said that in a previous interview, he learned that foreach is faster in VB.Net than c#'s foreach. He was told that this was because both have different CLR implementation.
Coming from a C++ perspective, I'm curious on why this is and I was told that I need to read up on CLR first. Googling foreach and CLR doesn't help me understand.
Does anyone have a good explanation on why foreach is faster in VB.Net than in c#? Or was my co-worker misinformed?
I have a directory with more then 350.000 files in. I need to process every single file and move them to an other folder. When I use the dir() method it takes a few seconds before if it returns the first file found. dim foundfile as string = dir("d:")
In the documentation there is this: "The My.Computer.FileSystem Object gives you greater productivity and performance in file I/O operations than the Dir function. See My.Computer.FileSystem.GetDirectoryInfo Method for more information."
But I can't find any method that is faster then dir, and gives the same result. I can't use this method below because it takes for ever to load...... For Each foundFile As String In My.Computer.FileSystem.GetFiles("D:") Next It just does not work fast...
When I use the Dir() method it takes like 5 sec, and it uses 100% cpu... it is just not a option. How do I get the same function as the dir method but better performance? (I use visual basic 2008).
I create a CSV file by getting a datatable then looping through that datatable and writing eachline of a CSV file. My data source usually has around 65,000 rows in it. This process takes several minutes to download from the browser. The problem is that locally and on dev it doesn't take too long, but on the client they usually timeout.
Is there a faster way to generate this file?
Function GenerateCSVFile() As String Dim stuPro As New studentProvider.StudentProvider Dim emailCenter As New EmailCenter
I need to verify if a certain user exist on my asp.net site.I want to know if which of these two functions is more efficient, faster and better compared to each other and why.
I worked in a role and functioning properly. The problem is that it is a bit slow for use in many images would be very slow. I read online that with stride and scan0 and working in memory with buffer can be made faster, but i donīt understand anything . Does anyone know how it works or how to make my code run faster?
I am loading images from the internet. I am using PictureBox1.imageLocation() but it takes a while to load the image. Is there a way i can load the images faster? it shows an error icon before it displays a picture...how can i get rid of that?
