I try to create a funtion to return a datareader from CSV file as below but got a error said that
ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified(at cn.open())
Public Shared Function GetCSVAsDataReader(ByVal csvPath As String) As Odbc.OdbcDataReader
Dim fi As New FileInfo(csvPath)
[Code]....
I am experiencing an error. I have a microsoft sql server database and need to colelct the data from the results and get the nullreference error shown below. I check the SQL string and executed it directly in the database and it yielded the correct results.
Quote: Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. 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. I use this code for connecting and reading the DB:
[Code]...
I have multiple documents stored in Attachment data type in Access database. UsingDataReader, I need to read multiple attachments along with their file name and store them on the file system
View 1 RepliesI have an SQL statement like:
SELECT FNAME, LNAME, CITY from EMPLOYEE
How do I create a multi-dimensional array from a datareader which should store values like:
John, Doe, LA
Mike, Johnson, PASADENA
Freddy, Kruger, Long Beach
How to convert CSV file to datareader?I google it but only find out how to convert datareader to CSV file.
View 3 RepliesI have a problem with my project. here is the problem:
My code for login is as follows:
dim conn as SqlConnection = New SqlConnection("Data Source.................)
dim cmd as SqlCommand = New SqlCommand("Loguser",conn)
cmd.CammandType = CommandType.StoredProcedure
[CODE]...
Now the error i get is that "there is a datareader associate with this connection that need to be closed"
I've wrote a program designed to loop through a text file containing email addresses and unsubscribe said email addresses in our CRM system. I'm having a problem with the following code...
Do While obj_filereader2.Peek() <> -1
strcuremail = obj_filereader2.ReadLine()
Dim dbqCustNo As String = "SQL CODE HERE - SELECT CUSTOMER NUMBER"
Dim exeCustNo As New SqlCommand()
Dim SQLdr As SqlDataReader
exeCustNo.Connection = ConnStr
[Code] ......
The program is falling over when trying to execute the update commands during the datareader loop, with the fabled 'There is already an open DataReader associated with this Command...' error. This program has evolved as I've found problems/better ways of working, so it might be a case of myself just not using the DataAdapter right - I'm guessing I should be using a function of the open DataReader rather than the ExecuteNonQuery command.
I am working on a project in VB 2008 and need it to do this:Read first line from text file (using Openfile)Enter line into textbox on formDo some other codeThen Read second linefrom text fileEnter line into same text boxand loop until we have gone through text fileI am not sure how to read line by line from text file then enter it in textbox. I can open the Openfile and get the filename and everything, but I just am not sure how to read from it or enter that line into the textbox.Here is what I have, its not much but its a start:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim FileReader As StreamReader
[code]....
I need to write data to a file, preferably in binary format, but I am unaccustomed with the concept. Where's the easiest place to get the basics? I could come here with a specific need, but I'm at the point right now where I am more willing to work within the confines of keeping it simple.
Here's what I know:
1. how to open a new file
2. how to specify the record length
3. how to close the file
Some specific questions:
Does the record length have to be constant throughout the file?
Can I read the nth record without reading the whole file?
I want to be able to able to read the dimensions of a TIF image without loading the entire file.
PS Using Visual Basic 2008 on Vista64.
I want to perform two hashing operations concurrently on a single file, without reading the file twice. Is there some way to share the FileStream between two synchronized hashing threads? For example:
Dim Stream As New IO.FileStream("...", IO.FileMode.Open)
Dim HashA, HashB As Byte()
Dim A = New System.Threading.Thread(Sub()
[code]....
Maybe some way of caching a stream? Trouble is, I don't want the entire file in memory at once (it could be many gigabytes in size) and I don't want the file read more than once, due to speed issues. I want the file cached only sufficiently to ensure that both threads can work.For example, suppose at some point in time, thread A had read 100k of the file, but thread B had only read 20k of the file. The portion of the file between 20k and 100k should be cached; but then progressively forgotten as thread B catches up. Then again, if thread B is too slow, we might still end up with hundreds of megabytes being cached.Maybe thread A should be made to wait while thread B catches up. Maybe the ReadByte() function of the stream should block for a while if one of the threads is too far behind?
I have a checked list box that is populated with the text from a text file. I started off with this code:
Dim FileToLoad As String
FileToLoad = TextBox3.Text
Dim fs As FileStream = New FileStream(FileToLoad, FileMode.Open)
[code].....
friend of mine has no HTML knowledge so I'm attempting to write a program that replaces certain parts of a html file to suit his needs.I've edited the HTML file and marked certain parts with "tags" like this:
#IMAGEURL1# I have a textbox where he can copy + paste an image URL and hopefully the #IMAGEURL1# is replaced with the contents of the textbox.
So can someone please enlighten me to-as how to open a HTML file (there's no textbox to display the contents just yet, I'll add one if needed), find the specified text and then replace it with whats in a textbox.
I am trying to import a TAB (NOt comma) delimited text file into a DataGridView. The following code works fine if I have a comma separated file. All I have to do is change the FMT to "Delimited".It just does not work with FMT=TabDelimited. All columns are read into single datatable column. The text file is ANSI text and I have double checked to make sure Tabs are tabs and not spaces, even exported a sample Tab Delimited file from Excel.Can this even be done using Text Driver? [code]
View 2 RepliesHow do I play a WAV file while the computer is reading aloud a text file? It uses Text to Speech synthesis and I need a laughter wav to play when the computer comes across something funny in the line.
View 2 RepliesI'm new to Visual Basic. I'm trying to get this code to read a .txt file line by line. If the only thing that the line says is "B" it should add one to the intTotalBoys integer and so on with G for Girls, F for Fathers, and M for Mothers. I'm not sure why it won't work. [code]
View 4 RepliesI would like to read from file, and ignore lines that start with --. I know how to read line by line but i just need to ignore those lines.
View 3 RepliesSo I need to write out an object to a text file as well as read in objects from text files.How do I accomplish this? This is the code i've used to read and write just simple lines of text. Is there a small modification to this or just a different function i use to read in an entire object?
Code:
Dim path As String
path = "Security.txt"
[code].....
I have just recently been using VB 2010 after using VB5. I have noticed a lot of changes. The problem I have is that I wish to open and save text files to and from arrays in the background. I've attached what I would do in VB5. I have searched around, but all the examples I find use a Textbox instead of an array. Can anyone show me how I can do this with VB 2010?
View 1 RepliesI got a log file (Log.txt) a timer and a RichTextBox1.Text The timer is opening the log file again and again every milisecond here the code:
Code:
Okay that keeps the track of my log file inside my richtextbox , but there is a big problem there. My richtextbox slows down hard if the log file gets too big.. Sometimes it kicks me out of the program and in taskbar it says Program Not Responding..
I wanted to know if there is a method to read a bigger Log file with out having such issues. (It mostly happens when log file goes over 13000 characters)
this code takes about 30 mins and high cpu usage, what is the problem
Do
strLine = objReader.ReadLine()
If strLine Is Nothing Then
[code].....
I am in the process (slow process) if learning vb.net by trying to create a simple application that will read and write (save) chosen information to a text file. The application has text boxes (name, email address, etc) and I want to read information from certain lines in the text and place in the given text box.
Code:
Dim StreamToDisplay As StreamReader
StreamToDisplay = New StreamReader("C: esting estfile.txt")
TextBox1.Text = StreamToDisplay.ReadLine()
StreamToDisplay.Close()
Currently it's reading the first line of text (which is "[username]").
Text file (testfile.txt) is attached
I have read a log file which is being used by a process. I could open the file in notepad or similar applications. The log file is not written by my application.
File.Open or streamreader gives me the following error: "An unhandled exception of type 'System.IO. IOException' occurred in mscorlib.dll. Additional information: The process cannot access the file "E:parkvbproject1.NETinsystem_log" because it is being used by another process."
i created a text file with some employee data in vb 2005, on my form i i have a bunch of textboxes and a combobox. i can load the employee numbers manually into the combobox but want the employee details to show in the textboxes when selecting the different employee numbers. i declared a structure with the various fields and a reader to read the text file. here is where i am stuck. my code thus far:
Public ABCStreamReader As StreamReader
[Code]...
I'm currently working on an app that grabs listings from a craigslist search (by saving the RSS feed from the results page as an XML file, and then reading it). However, I'm hitting an error.I have the code below in my Form1_Load event:
Code:
My.Computer.Network.DownloadFile("http://greenville.craigslist.org/search/sss?query=ipod%20touch&format=rss", "C:UsersBillDocumentsCLtemp.xml")
Dim CLsr As New System.IO.StreamReader("C:UsersBillDocumentsCLtemp.xml")
Dim CLxr As New System.Xml.XmlTextReader(CLsr)
[code].....
Basically I'm grabbing the RSS feed from the web [URL] currently just a test search for iPod touch being sold in Greenville, SC) and saving it as an XML file to the HDD temporarily to be read with a stream reader. Then, it just displays message boxes one after another showing the title of each post. However, when I run the program, I get the error on this line:
Code:
Dim posts As System.Xml.XmlNodeList = CLdataDoc.SelectNodes("rdf:RDF/item")
"Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function."
I'm working with VB.NET 2003 on Windows XP.I'm trying to read in from a text file and populate a listbox with the data. Below is my code:
Code:
If (File.Exists("users.txt")) Then
Dim text As String
FileOpen(1, "users.txt", OpenMode.Output)
Do
text = LineInput(1)
[Code]...
This code never populates the listbox and then on top of that it erases everything in the text file. What am i doing wrong?
this code takes about 60 mins and high cpu usage for a text file of 90,000 lines, what is the problem..[code]
View 9 RepliesI got the following code to read an XML file: [Code] Obviously the count limits the amount of lines that it reads. But how do I get it to read all the lines in the file? Ive tried removing the And (count <20) but when I run the program nothing happens.
View 2 RepliesI am using following code to read text from a .txt file. But I don't know how to perform search within file and how to read a specific line in the text file, based on search.
Dim vrDisplay = My.Computer.FileSystem.ReadAllText(CurDir() & "keys.txt")
MsgBox(vrDisplay)
For an example, if I want to read the line that contains the word "Start", how to do that?
I have an XML file, shown below:
<?xml version="1.0" standalone="no"?>
<!--RISInsight server settings-->
<Configuration>
[Code].....
Is there a way that I can make it continue to read the XML file?