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?
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 am creating an app that when a button is pressed a batch file is executed and hidden from view.I have managed to get the output of the batch file to be displayed in a text box.
View 1 RepliesI am writing an application that connects to a specific com port. This com port can change depending on how many physical ports are on the PC, and if other USB devices have installed com ports before this one.
I have the communication to the com port all working great, but I need to get the com port description not just the "COM#" which is all I currently get.
I found in the registry where the description is stored but am having trouble doing what I need.
In this key:
Code:
HKEY_LOCAL_MACHINESYSTEMControlSet001ControlClass{4D36E978-E325-11CE-BFC1-08002BE10318}
there is a varied number of sub keys. The are numbered 0000-NNNN depending on how many ports you have. Inside each of these keys, there are multiple values, although I am only interested in one or 2 of them.
My problem is, that I do not know how to get a list of the subkeys (the 0000-NNNN keys/folders) from the original key I posted. I have looked through a few registry tutorials, and I can view the default value in the listed key, but I could not find how to list the subkeys of the listed key.
Does anyone have any sample code they could share that shows how I can get a listing of subkeys, and then run through those subkeys checking for a specific value in one of the strings contained in the subkey?
I am using VB.net 2008 and Windows XP.
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 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 am developing some program which will frequently read a file and occasionally write to the file. The file, however, is extremely huge - it may contain hundred of thousands of rows, and each row has a particular meaning to the program. That, is there may be loads and loads of rows, and a row may contain additional elements.For instance, a row might look like the following:
Code:
3 00000111000000 01110110 2 0
I am writing my program in C#, just fyi.Given my very large file, I am refraining from the idea of just using a text file, which is an obvious choice. I am also hesitating to use a database and a table.
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 am trying to read all the attributes, there are 3, from a single node. This is what I tried from an example I found:
Code:
Dim xl As New XmlDocument
xl.Load(XMLfile)
Dim rn As XmlNode = xl.SelectSingleNode("p1")
[code]....
I have used a messagebox to show the xl.OuterXml, I see the file is loaded.
I want to read 'File.ini' line by line checking if specific text exists in the file and then display on a windows form weather particular settings are turned on or off.So far this code works if "TargetText" exists but if it doenst I get an error on the code line: "If line.Contains("TargetText") Then".
Code:
Using z As System.IO.StreamReader = New System.IO.StreamReader(File.ini")
Dim line As String
' Read first line.
[code]....
It works if "TargetText" exists in a line in the file but if it doesnt exist I get the 'Null Reference Exception. Object reference not set to an instance of an object.'
Alright this is what im working with. Im Working with vb.net 2003.I have (X) amount txt files in "C:Marble".In each txt files there are 3 lines.I want to read the first line of each txt file and display them in a listbox. [code] Things i need to Find:
-1 How to tell how many files are in a folder
-2 How to create a loop were it reads the first line of each file in that folder
I'm trying to read multiple values from a registry subkey in the CurrentUser key. I need to display these values in a listbox with multiple lines. I so far can only get one of the values from the subkey. I know (or at least I think I know) that I need to list the values in a string (with a possible loop), and then just display the string to the listbox. The subkey is the TypedURLs under CurrentUserSoftwareMicrosoftInternet Explorer Typed URLs. Here is my code I have so far (I did a year of basic VB as part of my Uni course).[code]
View 4 RepliesAn application that my company uses stores report files with a .dat extension for use with their software. These files can be opened in notepad and the basic report information can be seen as text. I am attempting to write an app that opens and reads data from these .dat files and displays it in a checked listbox. My hangup thus far is that I can't figure out how to read the data from the .dat files since they are not .txt files. Can anyone point me in the right direction?
[Code]...
I am working on a project that needs to read a file, no prob I have that part but, how do I code it to read the file and get say the highest, lowest, average and sum of the numbers in the file? Everything I have tried didn't work and left me with a blank application.
View 8 RepliesI have a txt file, that i want to read into my program. The problem is this:The textfile is a stats file for a game and looks like this:
Code:
ip:port wins username points
ip:port wins username points
ip:port wins username points
ip:port wins username points
ip:port wins username points
etc.
The main thing i want to do is sort these things out and then add to mysql database table that would have these columns:
Code:
ip authid wins username points
So what i wanna do is splitting this textfile data up and then adding everything to a mysql table.
I'm trying to return a integer / count of the ammount of files in the directory and sub directories in the 'Windows' folder, I need to be able to do this as fast as possible (no lag) and tell when it's done, hope I explained this right.
View 3 RepliesI wrote a cleanup program to go through some directories and delete files based on if the creation date is older than say 6 months. It works fine with some of the directories I have that contain around a few thousand small files. However, there is one directory (that contains small backup files from another program) that is loaded with over 300,000 files and it locks up on me as soon as I read in the first file in that directory.I am convinced it is the directory has too many files in it to open it. The server that the directory is on is slow. It takes a half hour to open the directory while on the server itself. I know it will take forever to delete the amount of files I want to delete, but I don't understand why it gets stuck and hangs there with no error message.Here is where I get stuck. Listbox1 is the directory I'm attempting to access
For Each selectFile In My.Computer.FileSystem.GetFiles(ListBox1.Items.Item(Count), FileIO.SearchOption.SearchTopLevelOnly, "*.*")
compFile = Path.GetFileName(selectFile)
[code].....
I require some help in saving and reading files in Line by Line format, How would I save to a specific line in the text file, or read a specific line?
[Code]...
I'm currently making a program that will be used to practice German. It reads from textfiles that have English words (noted by # prefix) and German words (noted by $ prefix). An example of this:
#hello $hallo
#good $gut
#evening $abends
The way it currently works is it loads a text file, finds all # and splits to an array called "English" and finds all $ and splits it to an array called "German" What I want it to now do is feed the "English" entries into textboxes on the left, and "German" onto textboxes on the right so I can then match them out and make a sort of memory game out of it. Unfortunately, I don't know how I would loop an array through multiple textboxes. Conveniently, the textboxes on the left have even numbers, and the ones on the right have odd. Is there a way to possibly find all evenly numbered textboxes and loop "English" array entries into them, and the same for "German"? I've realised this has now gotten a little convoluted, but hopefully somebody understands. I can screenshot the form for better explanation, and copy my existing source code if anybody wants it.
I'm trying to read an .rtf file one line at a time but I'm clearly missing something!The file contains 3 lines and I want each line to end-up in a different RichTextBox, so:
Open File
RichTextBox1 = 1st Line in File
RichTextBox2 = 2nd Line in File
RichTextBox3 = 3rd Line in File
Close File
What am I not understanding? I've tried using LoadFile to load the whole file into another RichTextBox first as I got the impression that RichTextBoxes are indexed - but what I got was strings not .rtf format. I've also looked to see if there's an equivalent of the text-centric ".ReadLine" and nothing seems to fit the bill.
I my old vb6 i use the tipical Open "c:somefile.vbw" For Output As #1 ecc...and loop into txt file line by line....Now i'am new in vb2010i need a little project in vb2010
View 1 RepliesI have a binary converter I am attempting to build and want to read and convert the InputTextBox(alphabetical characters) letter by letter however all I have so far is one letter at a time
Image here is the code I have so far:
Code:
Public Class ConverterForm
Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click
[Code]....