I want to import data from excel and move that to Datatable in VB.NET 2008. I wrote and working but its taking too long time.. for 1500 records its taking 4.40 min.
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i have a datatable with about 10000 rows and few columns (4)I have noticed that the process of reading a big table its quite slow..is there a way to improve performance in reading a datatable?
View 15 Repliesi'm developing vb.net application. There are 10 ways of transactions. I want to produce 'Purchase register report'. For that I want to find what amount of effect has been made by each transaction on ledgers of 'Purchase account'. Purchase account has almost 30 ledgers. And transactions can produce about 10000 rows in database for a year. Now if I produce month wise report for a year, there will be 10000*30=300000 row scanning which makes it very slow in execution.
View 6 RepliesI'm trying to improve my app with some error catching. I have a module that downloads a file from the Internet to a local folder. At the moment, if the local folder doesn't exist, it just crashes here:
strLocalFile = New FileStream(pPath, FileMode.Create, FileAccess.Write, FileShare.None)
with error:
System.IO.DirectoryNotFoundException was unhandled
Message="Could not find a part of the path 'C:Documents and SettingsSimonDesktop estdownload.zip'."
Source="mscorlib"
How can I do something with that error and stop my app from crashing? Ideally, have a messagebox show saying 'directory not found' or similar.
Dim ds As New DataSet
Dim xmlfile As XDocument = XDocument.Load("devices.xml")
Dim reader As XmlReader = xmlfile.CreateReader
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I have a repeater which takes 270 seconds to render and actually ends up crashing all browsers. The SQL to retrieve the data takes about 10 seconds. I wanted to remove the Eval's to see if that speeds up things a bit, but I am having trouble with the correct syntax. I have doubts that this would actually improve performance as I am dealing with 150,000 records. Would a GridView or other control be faster? Would using LINQ to SQL improve performance? Here is the code for the Eval:
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How can I improve the performance of a Windows Forms application?
View 1 Repliesimprove performance of Contact fetching using EWS managed API?
View 1 RepliesHow can I improve the performance of a Windows Forms application?
View 5 RepliesIf I took a COM object (specifically Excel 2003 workbook) and made it an embedded resource of my executable, would that improve the notoriously slow .NET-COM interop at all?
View 1 RepliesI'm currently working with a gridview that has a huge underlying dataset.I'm almost certain that I saw something about a new facility in Visual Studio 2010/.NET 4, which would improve the performance (e.g. doesn't download all the data on databind, but rather only what data required for current page). My guess would be that it was using AJAX.I didn't need it at the time I saw it, and now I can't find it, even though I've been hunting online for a while.
View 2 RepliesWhich one is more faster between DataTable and SqlDataReader while I'm trying to fill Data into FlexGrid with VB.NET?
View 3 RepliesI did ana application that interacts with excel (reading and writing files)But when the application ends and I close it, the excel file is still in the task manager procceses (ctrl+alt+del ->Proccesses)How can I completely close it?I'm using vb.net 2010 express
View 2 RepliesI have following code and it's slow to load first time. CSV file is about 4mb 16000 rows.
If Session("tb") Is Nothing Then
Dim str As String()
If (IsNothing(Cache("csvdata"))) Then
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I read a text file every second..[code]The file is generated from another program and it's costantly updated more times per second.The sense of the code (StartIndex) is to read only the rows that I have not read from the last time.The code works without problems until the file is about 2.5 Mb in dimensions... for higher dimensions I have problems and all becomes very slow.Using and fs.Dispose() are like Microsoft suggest (and in fact if i run the code analisys I have no problems), but surely the problem is not here.The question is: is my code right or there is way to improve the reading?? Is there way to read only the tail without to open the whole file?
View 5 RepliesI am trying to write the TOURN structure and then read the TOURN structure back in.. the file gets created on my desktop and the program does not have any syntax errors, but when I READ the file none of the Data gets retrieved. So I am not sure if the DATA was actually saved or it is just not being retrieved?? This is what I have coded so far...
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I am doing the project to make a microcontroller communicate with PC. I am facing the problem writing the C++ code for command button to ask uC to display the data in my label. How to write the code for C++ to get the data from the microcontroller?
i'm using a C8051F320-dk which already have a USB connector and a RTC.
my data will be the date, and time provided from the RTC.
The program that I am writing has three default variables that I would like it to store and also be able to change. I have them in a text file called "settings.txt" The format of the text file is as follows:
Default Source "I:DCIM101MSDCF"
Default Destination "C:Documents and SettingsChristyMy DocumentsMy Pictures"
Default Backup Destination "D:My DocumentsBackupMy Pictures"
The field descriptions eg "Default Source" take up 30 characters, so the variable data starts with character 30. I know their has to be an easy way just to pull out the data from a particular line starting with character 30 but I can't find it.
I�m currently working on a school project and I have encountered a problem in my code. When i write the contents of my listbox to a file called stock.txt it seems write an invisible linebreak in-between each data entry, my problem is that when I load my array on the next form those invisible linebreaks causes my array to load the data incorrectly.
I have attached a pic of my stock.txt file
The Code that Edits and writes to stock.txt
Private Sub BtnRemove_Click(sender As System.Object, e As System.EventArgs) Handles BtnRemove.Click
'Removes the selected item from the listbox then updates stock.txt
lbxStock.Items.Remove(lbxStock.Text)[code].....
Even a primer on just reading/writing to a text file would be golden. The array confuses me further, but understanding the data is primary.
Basically, we're writing a program to manage inventory for a bar. Fields and a few lines are below. The delimiter is "||"
So... How do we read the data into the arrays? NAME would be strName(), etc for all of them.
how to write and update existing data.
UID||BREWERY||NAME||SIZE||FORMAT||SEASONAL||PRICE||CASECOST||CASEQTY||BREWERYLOCATION||BREWSTYLE||ST YLE||ABV||CLASS
A0101.12B||Abita Brewing Company||Abita Amber||12
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I am using these API functions for my project where I am handling 3 unmanaged DLLs of two external apps, basically all it does is to carry data back and forth between these external applications. The project needs a lot of use of pointers, passing pointers and reading/writing to memory so both applications can talk to each other.
Declare Function HeapAlloc Lib "kernel32.dll" _
(ByVal hHeap As Long, ByVal dwFlags As Long, ByVal dwBytes As Long) As Long
Declare Function HeapCreate Lib "kernel32.dll" _
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set of windows API functions for allocating memory, reading and writing to allocated memory, and other required functions to generate required arguments to pass to these API calls?I am up to where I am allocating memory and getting pointer, but I don't know how to go about reading, writing, passing pointers, finding data lengths and reusing memory.
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reading and writing data to a serial port. the settings for the port are correct (from manual of device):
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I'm reading a file into a buffer using the Space function. Then I'm using blowfish dll's to encrypt it, and want to write the encrypted data to a txt file. (I realize you can use .NET cryptography classes, but I need to use these old blowfish dll's for this project.) Anyway, when when I encrypt the data in the buffer, I can see all encrypted data, but when I write it out to a file, I get a few lines of encrypted data and the rest of plain text.
HTML
' BLOCK_SIZE is a const which = 2048
sBlock = Space(BLOCK_SIZE)
Using sr As StreamReader = New StreamReader(FileToEncrypt)
sBlock = sr.ReadToEnd()
End Using[Code] ....
I have a basic page which has fields that I read from the database and write to it. I would like to know where I should call the insert and read commands. I know about age_load but heard about page_loadcomplete.I noted that when the user refreshes the page, for some reason the sqldatasource loads the old data(before the write) even though new data has been loaded on the form.
View 2 RepliesI want to import my data, which I receive over USB (every second), to an Excel sheet. Thing is, I want to open only one Excel file and write everything to this one file, and by pressing a "STOP" button, data reception will be canceled and data in the Excel file should be saved and Excel file should close right after that. Here my code,
Dim excel_cnt as Integer<br/>Dim sv_var as Integer = 0<br/><br/>Sub write_to_excel()
Dim xl As New Excel.Application
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I was developing a software with related to Excel, in which I have to write and SAVE the details at appropriate columns. I am currently having a problem in saving the data.
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'Open
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Very first time I debug the coding I haven't got much problem. But debugging it again gives me an Error AS: "A file named 'Resume.XLW' already exits in this location. Do you want to replace it?"
I was able to see this since I have enabled the display alerts. Disabling it generates a save as window.
I'm fairly new to coding in Visual Basic, and I'm working on a project where I have to allow users to write data to an existing Excel worksheet (by entering the data into a form created in Visual Basic.NET). I've created a form that allows users to enter data such as the following:
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I'm working on a project where I have to allow users to write data to an existing Excel worksheet (by entering the data into a form created in Visual Basic.NET). I've created a form that allows users to enter data such as the following:
Name (First, Last)
Mailing Address
Email Address
Gender
Age
...and so on. I've programmed the data to be sent to the Excel file upon clicking on the Submit button in the form itself. I've also created the Excel file and placed it on my C: drive, but the problem I'm having is trying to send the data from the VB form to the Excel file itself. Can someone please show me some sample code or point me in the right direction as to how to get the submitted information from the form to save into the Excel file, please?
I'm trying to get the information to show up in rows and columns in Excel like the following below (the dashes are just to show that the information should be in rows and columns):
Name--------------------------Mailing Address-------Email Address-------Gender-------Age
John Doe---------------------2300 Jackson Street-------- xxx@xxxx.com-------Male---------17
I have an application which opens one of several excel templates, fills a datagrid view with Excel Named Range data. Once the data is modified in the application I neet to save it to an excel spreadsheet. I currently have the following working:1. This sub writes 2 columns of data (Ingredient) and (Result) from those named ranges and places them in the datagrid
Private Sub CboBoxTypeCofA_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CboBoxTypeCofA.SelectedIndexChangedWorkbookTemplate = ""CofABook = ""
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This code works and the only problem is that after running the code the excel application does not close.Now I need to write the completed updates from the datagrid view and the other controls back into a workbook.Ive been searching around but have not found the proper way to do this and how to kill the oexcel application in the code above.
I'm writing a VB.NET program (VS 2005) that reads data from an XML document and writes it into a column in an excel spreadsheet. It's working fine, except for the following: after the first run, all the data appears as expected - for example
COLUMN
a
b
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