VS 2005 Strea Reader/Writer Delete Line
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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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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Apr 21, 2009
What is the code to make a stream writer remove a certain line from a file stream?
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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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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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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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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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Aug 16, 2009
You would think a search for this would show some results but I have had no luck.If I want to delete a line by a line number from a text file, how do I do that?
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Nov 25, 2009
Background: I am creating PDF with PrinceXML.I want to adjust the tracking on a paragraph in the PDF. So I select a unique piece of text, match it in the starting document, add a tracking attribute to the text, and re-create the PDF using PrinceXML.I have to delete the current PDF in order to create the revised PDF.When I was using the AxAcroPDF1 control in VB.NET all I needed to do was
1) If File.Exists(sPDFoutputName) Then File.Delete(sPDFoutputName)
Now I am trying to do the same thing but instead of using the AxAcroPDF control I am trying to do it with WebBrowser [Why am I doing this? Adobe places a burden on the developer to maintain a list of who has the program (Reader) to comply with US export law. This is an unacceptable requirement for the program.]
2)WebBrowser1.Navigate(sPDFoutputName + "#" + sPDFargument)
I want to jump to the same page that I was on so set the page to open in the sPDFarguement variable.Now when my program tries to delete as in #1 above I get error message that file is locked/in use.Question: How do I unload/close/unlock file in the webbrowser so I can delete it?The closest idea that I have found that almost works is to copy the xxxPDF to another file: displayPDF and only display the latter.With this I can delete and recreate a new xxxPDF. The problem again hits me when I try to delete the displayPDF. I have also tried to navigate to a dummyPDF but still displayPDF remains locked.
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Feb 1, 2012
I am working on a code that can read and display the rfid tag onto a textbox. What I am stuck on at the moment is that it displays all of the code from when a card is swiped over the rfid reader and I only want it to display the UID code only. The rfid code that comes up is as below:
IC Type: Philips Mifare UltraLight
Card UID: 0x88 04 BD 3F 49 BB 02 80
ATQA Byte[1]: 0x00 ATQA Byte[0]: 0x44 SAK: 0x00
[Code].....
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Jan 9, 2010
Is it possible that when a new line (anywhere in a richtextbox) is added/deleted, then a line is also added/deleted in another richtextbox?
[Code]...
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Apr 21, 2012
I am using this code to draw a line on a form using textboxes as the x and y coordinates. I then click the button with the code below that will draw the line.
Before the new line is drawn, I would like to have previous lines deleted first.
How can I delete these lines?
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim canvas As New ShapeContainer
[Code].....
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Apr 23, 2010
how to delete a richtextbox line, if the line only has one value. Ex:
[Code]...
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Nov 27, 2009
I am a student and I am about to make a program that will use a barcode scanner well ofcourse to scan a barcode. My problem is i don't know what library to use and what certain things i need to do so that when i am going to scan a barcode it'll be something like show it on a textbox and pull something from the database. i've actually research some. i've seen mscomm1 (not so sure about that) and POS for .net (haven't fully understood its use) were those will help me develop my program?
i have a metrologic ms9520 Voyager barcode scanner. and i am going to create a program for it in vb2005.
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Sep 9, 2009
i am having trouble deleting the individual rows in the datagrid. That is when the user select this row only this row will be deleted. i am getting some errors at the dataset there. the below is my code to delete from the database:
[Code]....
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Jun 17, 2011
how to connect barcode reader device into visual studio 2005? My device model is acanlogic cs-2030?
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Dec 24, 2009
I have two buttons: show button and next button. I want the show button to show the first result and then for every click of the next button, I want to go the the next result. I did this code for the show button:
cmd.Parameters.AddWithValue("@sex", TextBox4.Text)
dr = cmd.ExecuteScalar
If dr.HasRows Then
While (dr.Read)
TextBox1.Text = dr(0)
[Code] .....
Now the number of rows returned is 5. But on clicking the show button I can see only the last row in the textbox's. Then how to see the first row by clicking the show button? And how to see all rows one after another by clicking the next button? I need to use:
dr.NextResult()
to loop through the fetched data. But I cant place it properly in the next button code. How to do the code for show and next button to get the desired result?
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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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Aug 18, 2009
I have a show button.The user will select a data from the dropdown list of the combo and on clicking the show button the corresponding data will be fetched from the database and will be shown in the corresponding fields.So I did this
Private Sub Show_Btn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Show_Btn.Click
Using connection As New OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0;Data Source=BankAccount.mdb")
connection.Open()
Dim command As New OleDbCommand("Select * from BankAccount", connection)
Dim reader As OleDbDataReader = command.ExecuteReader()
[Code]...
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Feb 2, 2010
a text document containing information as:In/memory of/wendy/smith 6th of march 1545/ foreever in our thought/love liz and pony/i`ve got to develop a software in vb that will read the text file above and extract names, date.for each inscription it is required to display on a computer screen, IN TABULAR FORM, the details mention above.
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Jan 22, 2009
I have a form that has some combo boxes in it, and a table in SQL Server that stores the Values for the selected item for the combo box.I have read the data out from the combo box and inserted it into the SQL table as a integer. Now I want to read it back in to the form.
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Sep 5, 2011
how to connect barcode reader device into visual studio 2005? My device model is acanlogic cs-2030?
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Feb 4, 2009
How do i load a specific or a couple of line(not full file) to a RichTextBox by its line no...
For Example if i want load line 14...
Or sometime line 14-18...
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May 18, 2011
I want to launch a application called Foxit Reader pdf Reader .I know System.Diagnostics.Process.Start(path) can do it but . Requirements are Foxit Reader should be installed on machine.Now if it is installed how to serarch for the path of its Executable to provide the parameter as I can not hardcode the path for different machines.
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Feb 28, 2012
I am having an issue with both Adobe Reader and FoxIt Reader when trying to print a PDF document. Both issues are different but a solution to either one will allow me to fix my issue.The issue I am having with Adobe Reader when trying to print using the following code is that it will not print it to the network printer I specify but just the default printer.
Dim AdobeReader As New Process
AdobeReader.StartInfo.CreateNoWindow = False
AdobeReader.StartInfo.Verb = "print"
[code].....
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Dec 15, 2009
I have lines like this in my text file
10.0 28 Blue (B1-T54 ) [1 01.69 65.4] 47234 -22234 181017 76921
6.5 28 Blue (B1-T55 ) [1 01.80 50.2] 48234 -21234 203852 76133
11.0 28 Blue (B1-T56 ) [1 01.80 64.9] 48234 -22234 181804 76133
[code].....
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