Stream Writer / Reader - Modifying Time Intervals
Apr 28, 2009
I am new to Visual Basics and I am using Visual Basic 2008 express. I have been using video tutorial on line to learn VB and they are great in explaining what is happening the code vs. just looking at code. I think from what little I can find I would be using StreamWriter WriteLine and StreamReader readLine .I am using a couple of forms. I am looking for simple basic code to use a form as a way of modifying timer intervals and store the values in a single text file on separate lines.
Description:
Form1: will contain the main code that will run. It will contain some timers. I want the timers to look in a text file for their intervals. Each timer would be on a different line.
Example:
Timer1 interval would be located on line 3
Timer2 interval would be located on line 6
Timer3 interval would be located on line 20
Form2: will contain 3 textboxes. This is where when I load form2 I will also read the same values from the text file to preload the text boxes. I will now be able to change the timer intervals as needed and press a button to update the text file. The update button will also reload the new timer settings on Form1. This is very similar to how a CNC Machine works with Parameter settings. This can be useful for storing many different settings for a form that a user can modify and be stored and reloaded next time the program runs.
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Apr 30, 2009
The bigger problem is that I can't seem to get everything involving using stream writer and reader working. If I start of with a .txt file already correctly formatted then I can display it in the list box. But adding data during run time is not proving successful.
[Code]....
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Apr 28, 2011
I'm trying to setup a simple app that reads a file and then writes the contents to another file using OpenFileDialog and SaveFileDialog. Looking at the debbugger it looks like it's reading fine, I can see the data I want written. Towards the end of my code I get the following error message:"Illegal characters in path". I've researched this error. I'm not using any illegal characters such as /\? etc and the pathname contains all alpha characters. I'm pulling the test file from the C drive and trying to save it there as well.
Path: C:\Test.csv
My code:
Private Sub btnAppendData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAppendData.Click
Dim Result As DialogResult
Dim FileContents As String
[Code] .....
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Jan 27, 2009
I am trying to make my application read data from a file. Then save the data back. However I keep getting an error which says the file is still open so cannot be edited. I also read that there is an issue with the streamreader and streamwriter do not close the program straight away. I was wondering if anyone had a way around this or any alternative ideas. Heres my code so far!
[Code]...
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Sep 11, 2009
i am working on a project that uses an magnatec card reader mse-750 iam facing a problem in making the machine on read mode so i can read from it iam using vb.net?
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May 25, 2009
this project im working on is giving me a headache. am trying to write a program to recognie both ntfs and ext3 fileformats and enable the copying of files between them. ive done the ntfs bit and my problem is how do i implement the ext3 file system reader and writer using visual basic.net.any references would be really useful.
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Jul 2, 2010
I'm using the stream writer to make a text file and write to it.I'm trying to get all the items from the listbox2 and save them to a text file called log.txt.The funny part is that its not giving me a ex.message.Do you see any error.[code]...
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Jun 24, 2011
i am creating a program which scans and saves images. in my program i have the option to save images and with each image i save it gets its own number for example: file1, file2, file3, file4 and so on. the only problem i have is getting the prgram to remember where it left off so it carry's on the number. my understanding is that i need to create some sort of stream writer or file stream class for this proccess to work. so it save's the last image number i was on, and carrys it on next time i open the program up again. and i also need it to re-write the new image number its on for next time. so i need to write and read the text file (.txt) and write it again if you catch my drift? i have a book to help but the wording in it is so confusing at the min, i m lost where to start.
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Jul 9, 2010
I want to open a file with a stream writer. Delete it contains and write random data to it. And finally delete the file.
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Aug 22, 2009
I am having a strange issue when using the StreamWriter where I am getting some strange charachers in my text file when reading data from a query string.
[Code]...
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Nov 30, 2009
I have a dataGridView and tied it to a button that saves every time you click it. and every time you click it, I want to write a line to a txtfile that displays how many records were changed and the date that they were changed. Everything works fine but every time a save has been made it over write the previous entry on the text file. Here is some of the code.
If changes > 0 Then
MessageBox.Show(changes & " changed rows were stored in the database.") ' changes shows how many entries were changed
swDate.WriteLine(changes & " record changes on " & entryDate) 'entryDate is formated as date with value of "Now"
Else
[code]....
I am getting the right results in the text file except it over writes previous entry's so there is only one entry saved in the text file at any given time. I want it to keep building the text file so every time something is streamWrited the previous things in the text file stay there and it add to it. Looking at my problem I cant really justify or implement a For Each..Next or a Do While..Loop. My vb knowledge is limited so go easy on me.
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Oct 19, 2010
I'm making a browser and for the favorites I'm using a reader and writer to read and write new favorite to a .txt file. Now if I edit the text file manually and load up the browser, the favorites show up as they should but the problem comes in when I add the a new favourite and then reload the application. Once reloaded the favorites seem to copy what was originally in the file and then whatever I added last at the bottom.
Here is the
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
WebBrowser1.Navigate(TextBox1.Text)
ListBox1.Items.Add(TextBox1.Text)
[Code] .....
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Dec 6, 2010
I have a program that reads a text file tab delimted using OLEDb .I need to be able to allow the user to insert a user created record into the file which I can do.
The problem is I need to be able to let the user edit that record. From my understanding you can not edit or delete with OLEDB only insert So I thought I would read the file using stream reader, find the line I want to edit and just delete it, rewrite the file, then let the user insert a new record
If someone has a better way to perform this operation I am open its just the best way I could find with my limited knowledge and the reading and researching I have been doing thus far.
So I am trying to step-by step and first read the file which seems to work then find the line that would need to be deleted. So I was trying to use the
line.startswith method. I am using msgbox to see if that works before I continue but it doesnt seem to work I know my file has several lines starting with "Active" but my msgbox returns "False"
Here is the code I have so far
[code...]
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Apr 21, 2009
What is the code to make a stream writer remove a certain line from a file stream?
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May 8, 2009
We needed an inter-process reader/writer lock.We decided to use a file and lock the first byte using LockEx and UnlockEx. The class creates a file in the system temp folder when it is created. The file is created with readwrite access and share read|write|delete.We also specify DeleteOnClose so we don't leave loads of temp files laying around. Obviously AcquireReader and AcquireWriter call LockEx with appropriate flags and ReleaseLock calls UnlockEx.We have tested this class using a small application that you can run several instances of and it works perfectly. The application that uses it has a problem, which we have managed to re-produce in another small test app. In pseudo code it is
Create InterProcessReaderWriter
Dispose InterProcessReaderWriter without acquiring any locks
Launch a child process which takes a reader lock
The first time this runs, it works fine. If you attempt to run it again, while the child process from the first time is still holding the lock, we get an UnauthorisedAccessException when trying to open the file.This appears to be a permission issue, not a sharing violation but all the processes in this test case are running as the same user.
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Aug 6, 2009
I have a smart card reader/writer hooked up to my serial port. i've already coded the program to give access to the serial port. How would I go about getting my Card Reader/writer recognized in my program. I basically want to click the "read button" and whatever is on the current smart card im trying to read, pop up on the screen.
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Sep 24, 2008
how would I accomplish saving a large piece of data, using the Stream Reader for the Line-by-Line, while keeping the carriage return line feeds in there?
[Code]...
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Sep 7, 2010
I need to compare the current time with different time intervals, how can i get the time in this format so i can compare them.Format: 09:45:00
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Jun 18, 2012
How can i get my key's value using a stream reader [code]
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Apr 11, 2010
I have a stream reader going into an array with a .split on it:
strNstring = sr.ReadToEnd.Split(New [Char]() {" "c}, StringSplitOptions.RemoveEmptyEntries)
If the file is set up like:
the
dog ran and jumped
in
the grassy
[code]....
Is there any way to set the split to fix this and just have them come in correctly?
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Dec 30, 2008
I've set up a stream reader to get data from a serial file, functionality for that is already set up.
My problem is that the program seems to be missing out every other line of code in the file, which kinda defeats the point of a serial file. [code]...
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Feb 27, 2009
im trying to populate a list box from a text file using the System.IO.StreamReader class
and my code blows up right here:[code...]
The program dies at lstFilePreview.Items.Insert(Counter, ObjReader.Readline.ToString)and it gives me the "Object reference not set to an instance of an object." error.
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May 16, 2009
Radio button 2 beacuse there are 3 and you have to pick one (The right one) to advance on to the next form.
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Jul 2, 2009
Is there a method of using the stream reader to read webfiles?
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Apr 20, 2009
im trying to use a 2 combo boxes each with a list of 7 cities these need to link up with numbers in a stream reader to give a total distance.[code]
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Jun 24, 2010
I've got an application that reads a XML file via a stream reader. The problem is I can't edit my XML file and save it when others are using the application that is using the XML file at the time. how can i get around this?
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Apr 30, 2012
I have a text file name list.txt which contains data like following;
AC-No. Name Time State New State Exception
100 ZULFIQUAR 09/04/2012 01:53 PM C/In Invalid
100 ZULFIQUAR 10/04/2012 01:39 PM C/In Invalid
100 ZULFIQUAR 11/04/2012 01:38 PM C/In Invalid
[Code]....
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Oct 19, 2010
From few days I am doing efforts to read web pages using webbrowser control in my desktop application. But it is very slower than my expectations(because I want to read lots of pages in minutes and browser control reads almost one page in 5 to 10 seconds), what I need is to read two or three tags written in web page.
So finally I decided to use something, which can give me only source code of page. I think StreamReader will help me to read it. I am not sure if it is flaxible with my purpose, or something else is there which can give me only html source code of web page.
I have written this code to read html code, but it gives error.
Quote:
System.ArgumentException: URI formats are not supported.
public static string Navigate(string URL)
{
[code]....
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Jan 18, 2011
I have been using the following Stream Reader code for over a year now to pull information from 3 websites w/ no issues. Recently my users are getting massive amounts of "Timeout" errors. I have opened a ticket w/ the IT department but they have not found any issues (we are experiencing off/on issues w/ our web traffic speeds in our department). Per the code I have the timeout set to 20 seconds but the Timeout error occurs in only a few seconds from the System.Net.WebException.
Imports System.Text.RegularExpressions
Imports System.Net
Imports System.IO
[code]....
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Feb 1, 2009
I am downloading page data using the stream reader using readline.I want to concatenate each line into one long string for parsing The below line of code is not working: datajoined =dataline.Insert(datajoined.Length - 1, dataline.Length - 1)My inevitable goal here is to track stream data with a progress bar. But first I must learn to dload page data in chunks.
[Code]...
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